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Lu M, Li S, Han Z, Ma B, Wang L, Wan F, Lei S, Nie Y, Wang J. Carrying both the heterozygous Myh6-R453C and Tnnt2-R92W mutations aggravate the hypertrophic cardiomyopathy phenotype in mice. Biochem Biophys Res Commun 2024; 733:150582. [PMID: 39191188 DOI: 10.1016/j.bbrc.2024.150582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 08/04/2024] [Accepted: 08/20/2024] [Indexed: 08/29/2024]
Abstract
Hypertrophic cardiomyopathy (HCM) is an inherited disease of the heart muscle that is dominated by variations in eight genes encoding sarcomere proteins. Although there are clinical or basic research reports that carrying double mutations can lead to more severe HCM phenotypes, there are also research reports that after reanalyzing the reported mutations, the severity of clinical symptoms in patients with double mutations did not significantly increase compared to patients with only one mutation. To determine whether double pathogenic mutations can aggravate the phenotype of hypertrophic cardiomyopathy in mice, we constructed mice carrying single pathogenic heterozygous mutation Myh6-R453C or Tnnt2-R92W and mice carrying both pathogenic heterozygous mutations. Our results showed that mice with double heterozygous mutations exhibited significant hypertrophic cardiomyopathy phenotypes at 4 weeks of age, and the degree of hypertrophy was significantly higher than that of single heterozygous mutant mice of the same age. Our study suggests that carrying the two pathogenic heterozygous mutations simultaneously can aggravate the phenotype of HCM in mice, which provides experimental evidence for the genotype-phenotype relationship of double pathogenic mutations and provides reference significance for clinical risk stratification of HCM patients.
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Affiliation(s)
- Minjie Lu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuai Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ziqiang Han
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bingxuan Ma
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Leqi Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fangfang Wan
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Song Lei
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Cardiomyopathy Ward, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; National Clinical Research Center of Cardiovascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Yu Nie
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Jizheng Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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Saul T, Bui QM, Argiro A, Keyt L, Olivotto I, Adler E. Natural history and clinical outcomes of patients with hypertrophic cardiomyopathy from thin filament mutations. ESC Heart Fail 2024. [PMID: 38773858 DOI: 10.1002/ehf2.14848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 03/12/2024] [Accepted: 04/24/2024] [Indexed: 05/24/2024] Open
Abstract
Hypertrophic cardiomyopathy (HCM) due to thick filament variants is more common; however, HCM due to thin filament variants (HCM-Thin) may be associated with a more malignant phenotype with an increased risk of sudden cardiac death. The aim of this study was to review all the published cases of HCM-Thin to better understand the natural history and clinical outcomes of this disease. A literature review of HCM-Thin identified 21 studies with a total of 177 patients that were suitable for analysis. There were three outcomes of interest, which included a heart failure composite, a ventricular arrhythmia composite and a heart failure and arrhythmia composite outcome. Kaplan-Meier (KM) survival analyses for freedom from each of the abovementioned composite outcomes were completed for the entire cohort and stratified by age of onset and sarcomeric variant. The heart failure composite occurred in 24 (13.6%) patients, the ventricular arrhythmia composite occurred in 30 patients (16.9%) and the combined heart failure and arrhythmia composite occurred in 50 patients (28.2%). In regard to left ventricular ejection fraction (LVEF), the majority of patients were preserved (LVEF > 50%) compared with mildly reduced (LVEF 41%-50%) and reduced (LVEF ≤ 40%) (respectively 26.6% vs. 0.6% vs. 3.4%). The median maximal left ventricular wall thickness (LVWT) was 19.0 mm [interquartile range (IQR) 5.3]. Only 10.7% of the cohort had evidence of left ventricular outflow tract (LVOT) obstruction. Those with paediatric-onset HCM had earlier onset and were at higher risk for each endpoint than their adult counterparts. When stratified by genetic variant, patients with TNNI3 and TPM1 were at a higher risk of the heart failure composite endpoint and the combined heart failure and arrhythmia composite endpoint in comparison with those with the other genetic variants. HCM-Thin is associated with significant morbidity and mortality, with a high arrhythmia burden despite low rates of cardiac obstruction and mild hypertrophy. The paediatric onset of disease and certain sarcomeric variants appear to be associated with a worse prognosis than their adult-onset and other sarcomeric variant counterparts. HCM-Thin seems to have a distinct phenotype, which may require a different management approach.
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Affiliation(s)
- Tatiana Saul
- Division of Cardiovascular Medicine, Department of Medicine, University of California, San Diego, San Diego, California, USA
| | - Quan M Bui
- Division of Cardiovascular Medicine, Department of Medicine, University of California, San Diego, San Diego, California, USA
| | - Alessia Argiro
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy
| | - Lucas Keyt
- Division of Cardiovascular Medicine, Department of Medicine, University of California, San Diego, San Diego, California, USA
| | - Iacopo Olivotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy
| | - Eric Adler
- Division of Cardiovascular Medicine, Department of Medicine, University of California, San Diego, San Diego, California, USA
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Gaballa A, Jadam S, Desai MY. Promising therapies for adults with symptomatic obstructive hypertrophic cardiomyopathy: 2023 and beyond. Expert Opin Pharmacother 2024; 25:915-924. [PMID: 38813944 DOI: 10.1080/14656566.2024.2362902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 05/29/2024] [Indexed: 05/31/2024]
Abstract
INTRODUCTION Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic heart disease with an estimated prevalence in the general population of 0.2% to 0.6%. Clinically, HCM can range from no symptoms to severe symptoms such as heart failure or sudden cardiac death. Currently, the management of HCM involves lifestyle modifications, familial screening, genetic counseling, pharmacotherapy to manage symptoms, sudden cardiac death risk assessment, septal reduction therapy, and heart transplantation for specific patients. Multicenter randomized controlled trials have only recently explored the potential of cardiac myosin inhibitors (CMIs) such as mavacamten as a directed pharmacological approach for managing HCM. AREAS COVERED We will assess the existing medical treatments for HCM: beta-blockers, calcium channel blockers, disopyramide, and different CMIs. We will also discuss future HCM pharmacotherapy guidelines and underline this patient population's unfulfilled needs. EXPERT OPINION Mavacamten is the first-in-class CMI approved by the FDA to target HCM pathophysiology specifically. Mavacamten should be incorporated into the standard therapy for oHCM in case of symptom persistence despite using maximally tolerated beta blockers and/or calcium channel blockers. Potential drug-drug interactions should be assessed before initiating this drug. More studies are needed on the use of CMIs in patients with kidney and/or liver failure and pregnant/breastfeeding patients.
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Affiliation(s)
- Andrew Gaballa
- Hypertrophic Cardiomyopathy Center, Cleveland Clinic, Cleveland, OH, USA
| | - Shada Jadam
- Hypertrophic Cardiomyopathy Center, Cleveland Clinic, Cleveland, OH, USA
| | - Milind Y Desai
- Hypertrophic Cardiomyopathy Center, Cleveland Clinic, Cleveland, OH, USA
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Cianci V, Forzese E, Sapienza D, Cardia L, Cianci A, Germanà A, Tornese L, Ieni A, Gualniera P, Asmundo A, Mondello C. Morphological and Genetic Aspects for Post-Mortem Diagnosis of Hypertrophic Cardiomyopathy: A Systematic Review. Int J Mol Sci 2024; 25:1275. [PMID: 38279275 PMCID: PMC10816624 DOI: 10.3390/ijms25021275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiovascular diseases, and it shows an autosomal dominant pattern of inheritance. HCM can be clinically silent, and sudden unexpected death due to malignant arrhythmias may be the first manifestation. Thus, the HCM diagnosis could be performed at a clinical and judicial autopsy and offer useful findings on morphological features; moreover, it could integrate the knowledge on the genetic aspect of the disease. This review aims to systematically analyze the literature on the main post-mortem investigations and the related findings of HCM to reach a well-characterized and stringent diagnosis; the review was performed using PubMed and Scopus databases. The articles on the post-mortem evaluation of HCM by gross and microscopic evaluation, imaging, and genetic test were selected; a total of 36 studies were included. HCM was described with a wide range of gross findings, and there were cases without morphological alterations. Myocyte hypertrophy, disarray, fibrosis, and small vessel disease were the main histological findings. The post-mortem genetic tests allowed the diagnosis to be reached in cases without morpho-structural abnormalities; clinical and forensic pathologists have a pivotal role in HCM diagnosis; they contribute to a better definition of the disease and also provide data on the genotype-phenotype correlation, which is useful for clinical research.
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Affiliation(s)
- Vincenzo Cianci
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Elena Forzese
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Daniela Sapienza
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Luigi Cardia
- Department of Human Pathology of Adult and Childhood “Gaetano Barresi”, University of Messina, Via C. Valeria 1, 98125 Messina, Italy; (L.C.); (A.I.)
| | - Alessio Cianci
- Department of Cardiovascular Medicine, Fondazione Policlinico Universitario A. Gemelli-IRCCS, Largo A. Gemelli 8, 00168 Rome, Italy;
| | - Antonino Germanà
- Zebrafish Neuromorphology Laboratory, Department of Veterinary Sciences, University of Messina, Via Palatucci snc, 98168 Messina, Italy;
| | - Lorenzo Tornese
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Antonio Ieni
- Department of Human Pathology of Adult and Childhood “Gaetano Barresi”, University of Messina, Via C. Valeria 1, 98125 Messina, Italy; (L.C.); (A.I.)
| | - Patrizia Gualniera
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Alessio Asmundo
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Cristina Mondello
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
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Murata H, Miyauchi Y, Nitta T, Sakamoto SI, Kunugi S, Ishii Y, Shimizu A, Fujimoto Y, Hayashi H, Yamamoto T, Yodogawa K, Maruyama M, Kaneko S, Hayashi H, Soejima K, Nogami A, Asai K, Shimizu W, Iwasaki YK. Electrophysiological and Histopathological Characteristics of Ventricular Tachycardia Associated With Primary Cardiac Tumors. JACC Clin Electrophysiol 2024; 10:43-55. [PMID: 37855769 DOI: 10.1016/j.jacep.2023.08.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/11/2023] [Accepted: 08/30/2023] [Indexed: 10/20/2023]
Abstract
BACKGROUND Ventricular tachycardia (VT) associated with primary cardiac tumors (PCTs) originating from the ventricles is rare, but lethal, in young patients. OBJECTIVES This study aimed to clarify the mechanisms underlying primary cardiac tumor-related ventricular tachycardia (PCT-VT) and establish a therapeutic strategy for this form of VT. METHODS Among 67 patients who underwent surgery for VT at our institute between 1981 and 2020, 4 patients aged 1 to 34 years, including 3 males, showed PCT-VT (fibroma, 2; lipoma, 1; and hamartoma, 1), which was investigated using a combination of intraoperative electroanatomical mapping and histopathological studies. RESULTS All 4 patients developed electrical storms of sustained VTs refractory to multiple drugs and repetitive endocardial ablations. The VT mechanism was re-entry, and intraoperative electroanatomical mapping showed a centrifugal activation pattern originating from the border between the tumor and healthy myocardium, where fractionated potentials were detected during sinus rhythm. Histopathological studies of serial sections of specimens acquired from these areas revealed tumor infiltration into the surrounding myocardium with cell disorganization, exhibiting myocardial disarray. Several myocardia entrapped in the tumor edges contributed to the development and sustainment of re-entrant VT activation. In the 2 patients in whom complete resection was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing VT occurrence. CONCLUSIONS The mechanism underlying PCT-VT involves re-entry localized at the tumor edges. Myocardial disarray associated with tumor infiltration is a substrate for this form of VT. Cryoablation along the border between the tumor and myocardium is a promising therapeutic option for unresectable PCT-VT.
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Affiliation(s)
- Hiroshige Murata
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan. https://twitter.com/Muratahiroshige
| | - Yasushi Miyauchi
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Takashi Nitta
- Department of Cardiovascular Surgery, Nippon Medical School, Tokyo, Japan
| | | | - Shinobu Kunugi
- Department of Analytic Human Pathology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yosuke Ishii
- Department of Cardiovascular Surgery, Nippon Medical School, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yuhi Fujimoto
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Hiroshi Hayashi
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Teppei Yamamoto
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Kenji Yodogawa
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Mitsunori Maruyama
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Shinji Kaneko
- Department of Cardiology, Toyota Kosei Hospital, Aichi, Japan
| | - Hidemori Hayashi
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kyoko Soejima
- Department of Cardiology, Kyorin University, Tokyo, Japan
| | - Akihiko Nogami
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Kuniya Asai
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Yu-Ki Iwasaki
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
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Mehra N, Ali AH, Desai MY. Obstructive hypertrophic cardiomyopathy: a review of new therapies. Future Cardiol 2023; 19:661-670. [PMID: 37933625 DOI: 10.2217/fca-2023-0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 09/13/2023] [Indexed: 11/08/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a phenotypically heterogeneous disease with a genetic basis and variable penetrance. The hallmarks of HCM include dynamic left ventricular outflow tract obstruction, typically caused by asymmetric septal hypertrophy. However, abnormal papillary muscle placement, abnormal mitral valve and subvalvular apparatus and apical hypertrophic forms have also been described. Typical medical treatment has been stagnant for decades, although there have been significant advances in surgical treatment of patients with obstructive HCM. Herein, we describe a new class of drugs targeting the specific pathophysiology of HCM.
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Affiliation(s)
- Nandini Mehra
- Hypertrophic Cardiomyopathy Center, Heart Vascular Thoracic Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Adel Hajj Ali
- Hypertrophic Cardiomyopathy Center, Heart Vascular Thoracic Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Internal Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Milind Y Desai
- Hypertrophic Cardiomyopathy Center, Heart Vascular Thoracic Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Wong J, Peters S, Marwick TH. Phenotyping heart failure by genetics and associated conditions. Eur Heart J Cardiovasc Imaging 2023; 24:1293-1301. [PMID: 37279791 DOI: 10.1093/ehjci/jead125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 05/26/2023] [Indexed: 06/08/2023] Open
Abstract
Heart failure is a highly heterogeneous disease, and genetic testing may allow phenotypic distinctions that are incremental to those obtainable from imaging. Advances in genetic testing have allowed for the identification of deleterious variants in patients with specific heart failure phenotypes (dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and hypertrophic cardiomyopathy), and many of these have specific treatment implications. The diagnostic yield of genetic testing in heart failure is modest, and many rare variants are associated with incomplete penetrance and variable expressivity. Environmental factors and co-morbidities have a large role in the heterogeneity of the heart failure phenotype. Future endeavours should concentrate on the cumulative impact of genetic polymorphisms in the development of heart failure.
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Affiliation(s)
- Joshua Wong
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
| | - Stacey Peters
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
| | - Thomas H Marwick
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
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Hajj Ali A, Mehra N, Desai MY. Hypertrophic cardiomyopathy: investigational drugs inhibiting myosin and upcoming agents. Expert Opin Investig Drugs 2023; 32:849-853. [PMID: 37787068 DOI: 10.1080/13543784.2023.2263362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 09/22/2023] [Indexed: 10/04/2023]
Abstract
INTRODUCTION Hypertrophic cardiomyopathy (HCM), a phenotypically variable disorder with a genetic basis, was first described in the late 1800s. Since the discovery of the disease, various medical and surgical treatments have been proposed with surgical treatments proving to be of more benefit than medical in patients with severe symptoms. Although beta blockers, calcium channel blockers, and disopyramide have been used for their negative inotropic effect, the data behind utilization of these medications is weak at best. AREAS COVERED Herein, we describe a first-in-man class of medications called cardiac myosin inhibitors (CMI), which have been recently approved by the Food and Drug Administration (FDA) for the treatment of symptomatic patients with obstructive HCM. PubMed was the primary database searched. EXPERT OPINION Whether these medications will stand the test of time remains to be seen. They do appear to provide significant benefit and disease modification in early randomized trials with the drawback of decreasing contractility and ejection fraction. In our opinion, this new class of medications is an option for patients with NYHA class II-III symptoms from obstructive HCM who have EF ≥ 55%.
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Affiliation(s)
- Adel Hajj Ali
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Nandini Mehra
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Milind Y Desai
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
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Desai MY, Hajj Ali A. Mavacamten, an Alternative to Septal Reduction Therapy for Patients with Hypertrophic Cardiomyopathy. Heart Int 2023; 17:2-4. [PMID: 37456351 PMCID: PMC10339467 DOI: 10.17925/hi.2023.17.1.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/27/2023] [Indexed: 07/18/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common heridetary cardiac disorder characterized by a wide range of symptoms. The pharmacological treatment of HCM is currently limited to beta blockers, non-dihydropyridine calcium channel blockers and disopyramide. Mavacamten is a novel cardiac myosin inhibitor, which was recently added to the limited pharmacological list of treatment options for HCM. This editorial elaborates on current evidence evaluating the use of mavacamten in patients with symptomatic obstructive HCM, comments on its current use and its expanded potential applications in the future.
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Affiliation(s)
- Milind Y Desai
- Hypertrophic Cardiomyopathy Center, Heart Vascular Thoracic Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Adel Hajj Ali
- Hypertrophic Cardiomyopathy Center, Heart Vascular Thoracic Institute, Cleveland Clinic, Cleveland, OH, USA
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10
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Sau A, Ng FS. Hypertrophic cardiomyopathy risk stratification based on clinical or dynamic electrophysiological features: two sides of the same coin. Europace 2023; 25:euad072. [PMID: 36943002 PMCID: PMC10228291 DOI: 10.1093/europace/euad072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Affiliation(s)
- Arunashis Sau
- National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
- Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, 72 Du Cane Road, W12 0HS, London, UK
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
- Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, 72 Du Cane Road, W12 0HS, London, UK
- Department of Cardiology, Chelsea and Westminster Hospital NHS Foundation Trust, 369 Fulham Road, SW10 9NH, London, UK
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11
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Park YM. Updated risk assessments for sudden cardiac death in hypertrophic cardiomyopathy patients with implantable cardioverter-defibrillator. Korean J Intern Med 2023; 38:7-15. [PMID: 36353786 PMCID: PMC9816680 DOI: 10.3904/kjim.2022.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/16/2022] [Indexed: 11/11/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disease associated with a risk of malignant ventricular tachyarrhythmias and sudden cardiac death (SCD). Assessment of the SCD risk is crucial for its clinical management, and there has been considerable interest in developing risk stratification strategies. An implantable cardioverter-defibrillator (ICD) is a life-saving treatment for patients with HCM who are at a high-risk of ventricular tachyarrhythmias and SCD. However, a substantial number of ICD recipients experience adverse effects arising from inappropriate device therapy and implant-related complications. This has led to numerous investigations of the risk of SCD and the indications for ICD implantation. American guidelines were recently updated to include new risk markers, including left ventricular systolic dysfunction, apical aneurysm, and extensive late gadolinium enhancement, while European guidelines recommend individualized estimated 5-year SCD risk assessment models. Studies evaluating other risk factors for SCD in patients with HCM have also been published. Drawing on recent guidelines and publications on clinical risk factors, we focus this review on updated risk assessments for SCD with ICD therapy in patients with HCM.
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Affiliation(s)
- Yae Min Park
- Division of Cardiology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
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12
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Sukhacheva TV, Serov RA, Malenkov DA, Berseneva MI, Bokeria LA. [Morphology of the myocardium of the interventricular septum in children with hypertrophic cardiomyopathy]. Arkh Patol 2023; 85:5-15. [PMID: 38010634 DOI: 10.17116/patol2023850615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
OBJECTIVE To carry out a comparative analysis of the morphology of the interventricular septum (IVS) myocardium in children with hypertrophic cardiomyopathy (HCM) and without cardiovascular pathology. MATERIAL AND METHODS A study of myocardial biopsies of the IVS in children with HCM (n=18, 1.2-17 years) and children without cardiovascular pathology (n=11, 1-16 years) was carried out. The volume of interstitial tissue in the IVS myocardium was determined, a morphometric study of the size of cardiomyocytes (CMCs), the myofibrillogenesis level and the ploidy of CMCs was carried out, the ultrastructure of the CMCs was studied, and the localization of the gap junction protein, connexin43 (Cx43), was revealed by immunohistochemistry. RESULTS The proportion of interstitial tissue in the myocardium of children with HCM was 9-10% and did not differ from its proportion in the myocardium of children in the control group. The diameter of the CMCs of the IVS in children with HCM reached the limit of ontogenetic growth and exceeded the parameters of the control group (average 18.9±5.7 µm vs 9.3±4.4 µm). CMCs ploidy in children with HCM was 2 times higher than CMCs ploidy in control patients (5.3c vs 2.7c). In the myocardium of children with HCM, the assembly of myofibrils most actively occurred in small CMCs. At the ultrastructural level, signs of immaturity of the contractile apparatus and intercalated discs of the CMC in HCM were demonstrated. In the myocardium of children with HCM, Cx43-containing gap junctions were more often located on the lateral surfaces of the CMC than in the myocardium of the control group. CONCLUSION In children with HCM, a morphological picture of an increase in the size of the CMCs and their ploidy during accelerated ontogenetic development was demonstrated in combination with ultrastructural signs of immaturity of the contractile apparatus and intercalated discs and the lack of growth of interstitial tissue of the IVS myocardium compared with patients in the control group.
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Affiliation(s)
- T V Sukhacheva
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
| | - R A Serov
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
| | - D A Malenkov
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
| | - M I Berseneva
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
| | - L A Bokeria
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
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13
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Parker LE, Kramer RJ, Kaplan S, Landstrom AP. One gene, two modes of inheritance, four diseases: A systematic review of the cardiac manifestation of pathogenic variants in JPH2-encoded junctophilin-2. Trends Cardiovasc Med 2023; 33:1-10. [PMID: 34861382 PMCID: PMC9156715 DOI: 10.1016/j.tcm.2021.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 02/01/2023]
Abstract
Rare variants in JPH2 have been associated with a range of cardiac disease, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmias, and sudden cardiac death (SCD); however, our understanding of how variants in JPH2 correspond to specific modes of inheritance and correlate clinical phenotypes has not been comprehensively explored. In this systematic review, we assess current case reports and series that describe patients with JPH2 variants and cardiac disease. We identified a total of 61 variant-positive individuals, approximately 80% of whom had some form of cardiac disease, including 47% HCM, 18% DCM, and 14% arrhythmia/SCD. In analyzing the 24 probands described in the studies, we found that autosomal recessive, loss-of-function variants are associated with severe, early onset DCM, while autosomal dominant missense variants are associated with a wider range of cardiac disease, including HCM, arrhythmia, SCD, and cardiac conduction disease.
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Affiliation(s)
- Lauren E Parker
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, NC, United States
| | - Ryan J Kramer
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, NC, United States
| | - Samantha Kaplan
- Medical Center Library and Archives, Duke University, Durham, NC, United States
| | - Andrew P Landstrom
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, NC, United States; Department of Cell Biology, Duke University School of Medicine, Durham, NC, United States.
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14
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Risi CM, Belknap B, White HD, Dryden K, Pinto JR, Chase PB, Galkin VE. High-resolution cryo-EM structure of the junction region of the native cardiac thin filament in relaxed state. PNAS NEXUS 2023; 2:pgac298. [PMID: 36712934 PMCID: PMC9832952 DOI: 10.1093/pnasnexus/pgac298] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Cardiac contraction depends on molecular interactions among sarcomeric proteins coordinated by the rising and falling intracellular Ca2+ levels. Cardiac thin filament (cTF) consists of two strands composed of actin, tropomyosin (Tm), and equally spaced troponin (Tn) complexes forming regulatory units. Tn binds Ca2+ to move Tm strand away from myosin-binding sites on actin to enable actomyosin cross-bridges required for force generation. The Tn complex has three subunits-Ca2+-binding TnC, inhibitory TnI, and Tm-binding TnT. Tm strand is comprised of adjacent Tm molecules that overlap "head-to-tail" along the actin filament. The N-terminus of TnT (e.g., TnT1) binds to the Tm overlap region to form the cTF junction region-the region that connects adjacent regulatory units and confers to cTF internal cooperativity. Numerous studies have predicted interactions among actin, Tm, and TnT1 within the junction region, although a direct structural description of the cTF junction region awaited completion. Here, we report a 3.8 Å resolution cryo-EM structure of the native cTF junction region at relaxing (pCa 8) Ca2+ conditions. We provide novel insights into the "head-to-tail" interactions between adjacent Tm molecules and interactions between the Tm junction with F-actin. We demonstrate how TnT1 stabilizes the Tm overlap region via its interactions with the Tm C- and N-termini and actin. Our data show that TnT1 works as a joint that anchors the Tm overlap region to actin, which stabilizes the relaxed state of the cTF. Our structure provides insight into the molecular basis of cardiac diseases caused by missense mutations in TnT1.
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Affiliation(s)
- Cristina M Risi
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Betty Belknap
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Howard D White
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Kelly Dryden
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32304, USA
| | - P Bryant Chase
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Vitold E Galkin
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA 23507, USA
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15
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Keyt LK, Duran JM, Bui QM, Chen C, Miyamoto MI, Silva Enciso J, Tardiff JC, Adler ED. Thin filament cardiomyopathies: A review of genetics, disease mechanisms, and emerging therapeutics. Front Cardiovasc Med 2022; 9:972301. [PMID: 36158814 PMCID: PMC9489950 DOI: 10.3389/fcvm.2022.972301] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 07/28/2022] [Indexed: 11/17/2022] Open
Abstract
All muscle contraction occurs due to the cyclical interaction between sarcomeric thin and thick filament proteins within the myocyte. The thin filament consists of the proteins actin, tropomyosin, Troponin C, Troponin I, and Troponin T. Mutations in these proteins can result in various forms of cardiomyopathy, including hypertrophic, restrictive, and dilated phenotypes and account for as many as 30% of all cases of inherited cardiomyopathy. There is significant evidence that thin filament mutations contribute to dysregulation of Ca2+ within the sarcomere and may have a distinct pathomechanism of disease from cardiomyopathy associated with thick filament mutations. A number of distinct clinical findings appear to be correlated with thin-filament mutations: greater degrees of restrictive cardiomyopathy and relatively less left ventricular (LV) hypertrophy and LV outflow tract obstruction than that seen with thick filament mutations, increased morbidity associated with heart failure, increased arrhythmia burden and potentially higher mortality. Most therapies that improve outcomes in heart failure blunt the neurohormonal pathways involved in cardiac remodeling, while most therapies for hypertrophic cardiomyopathy involve use of negative inotropes to reduce LV hypertrophy or septal reduction therapies to reduce LV outflow tract obstruction. None of these therapies directly address the underlying sarcomeric dysfunction associated with thin-filament mutations. With mounting evidence that thin filament cardiomyopathies occur through a distinct mechanism, there is need for therapies targeting the unique, underlying mechanisms tailored for each patient depending on a given mutation.
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Affiliation(s)
- Lucas K. Keyt
- Department of Internal Medicine, University of California, San Diego, San Diego, CA, United States
| | - Jason M. Duran
- Department of Cardiology, University of California, San Diego, San Diego, CA, United States
| | - Quan M. Bui
- Department of Cardiology, University of California, San Diego, San Diego, CA, United States
| | - Chao Chen
- Department of Cardiology, University of California, San Diego, San Diego, CA, United States
| | | | - Jorge Silva Enciso
- Department of Cardiology, University of California, San Diego, San Diego, CA, United States
| | - Jil C. Tardiff
- Department of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ, United States
| | - Eric D. Adler
- Department of Cardiology, University of California, San Diego, San Diego, CA, United States
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16
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Zhang Y, Peng R, Wang H. Identification and genetic analysis of rare variants in myosin family genes in 412 Han Chinese congenital heart disease patients. Mol Genet Genomic Med 2022; 10:e2041. [PMID: 35993536 PMCID: PMC9544220 DOI: 10.1002/mgg3.2041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/23/2022] [Accepted: 08/07/2022] [Indexed: 11/17/2022] Open
Abstract
Background Myosin family genes, including those encoding myosin heavy chain 6, myosin heavy chain 7, myosin light chain 3, and myosin light chain 2 (MYL2), are important genetic factors in congenital heart disease (CHD). However, how these genes contribute to CHD in the Han Chinese population remains unclear. Methods We sequenced myosin family genes in a Han Chinese cohort comprising 412 CHD patients and 213 matched controls in the present study. A zebrafish model was used to evaluate the pathogenicity of rare mutations in MYL2. Results We identified 30 known mutations and 12 novel mutations. Furthermore, the contributions of two novel mutations, MYL2 p.Ile158Thr and p.Val146Met, to CHD were analyzed. The p.Ile158Thr mutation increased MYL2 expression. In zebrafish embryos, injection of myl2b‐targeting morpholinos led to aberrant cardiac structures, an effect that was reversed by expression of wild‐type MYL2 but not MYL2 p.Ile158Thr and pVal146Met. Conclusions Overall, our findings suggest that MYL2 p.Ile158Thr and p.Val146Met contribute to the etiology of CHD. The results also indicate the importance of MYL2 in heart formation.
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Affiliation(s)
- Yunqian Zhang
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, State Key Laboratory of Genetic Engineering at School of Life Sciences, Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China
| | - Rui Peng
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, State Key Laboratory of Genetic Engineering at School of Life Sciences, Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,NHC Key Lab of Reproduction (Shanghai Institute of Planned Parenthood Research), Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China
| | - Hongyan Wang
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, State Key Laboratory of Genetic Engineering at School of Life Sciences, Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,NHC Key Lab of Reproduction (Shanghai Institute of Planned Parenthood Research), Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China.,Children's Hospital, Fudan University, Shanghai, China.,The Institutes of Biomedical Sciences, Fudan University, Shanghai, China
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17
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Barefield DY, Yamakawa S, Tahtah I, Sell JJ, Broman M, Laforest B, Harris S, Alvarez AA, Araujo KN, Puckelwartz MJ, Wasserstrom JA, Fishman GI, McNally EM. Partial and complete loss of myosin binding protein H-like cause cardiac conduction defects. J Mol Cell Cardiol 2022; 169:28-40. [PMID: 35533732 PMCID: PMC9329245 DOI: 10.1016/j.yjmcc.2022.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 03/25/2022] [Accepted: 04/15/2022] [Indexed: 02/04/2023]
Abstract
A premature truncation of MYBPHL in humans and a loss of Mybphl in mice is associated with dilated cardiomyopathy, atrial and ventricular arrhythmias, and atrial enlargement. MYBPHL encodes myosin binding protein H-like (MyBP-HL). Prior work in mice indirectly identified Mybphl expression in the atria and in small puncta throughout the ventricle. Because of its genetic association with human and mouse cardiac conduction system disease, we evaluated the anatomical localization of MyBP-HL and the consequences of loss of MyBP-HL on conduction system function. Immunofluorescence microscopy of normal adult mouse ventricles identified MyBP-HL-positive ventricular cardiomyocytes that co-localized with the ventricular conduction system marker contactin-2 near the atrioventricular node and in a subset of Purkinje fibers. Mybphl heterozygous ventricles had a marked reduction of MyBP-HL-positive cells compared to controls. Lightsheet microscopy of normal perinatal day 5 mouse hearts showed enrichment of MyBP-HL-positive cells within and immediately adjacent to the contactin-2-positive ventricular conduction system, but this association was not apparent in Mybphl heterozygous hearts. Surface telemetry of Mybphl-null mice revealed atrioventricular block and atrial bigeminy, while intracardiac pacing revealed a shorter atrial relative refractory period and atrial tachycardia. Calcium transient analysis of isolated Mybphl-null atrial cardiomyocytes demonstrated an increased heterogeneity of calcium release and faster rates of calcium release compared to wild type controls. Super-resolution microscopy of Mybphl heterozygous and homozygous null atrial cardiomyocytes showed ryanodine receptor disorganization compared to wild type controls. Abnormal calcium release, shorter atrial refractory period, and atrial dilation seen in Mybphl null, but not wild type control hearts, agree with the observed atrial arrhythmias, bigeminy, and atrial tachycardia, whereas the proximity of MyBP-HL-positive cells with the ventricular conduction system provides insight into how a predominantly atrial expressed gene contributes to ventricular arrhythmias and ventricular dysfunction.
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Affiliation(s)
- David Y. Barefield
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL;,Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL;,Correspondence to: David Y. Barefield, PhD, Department of Cell and Molecular Physiology Loyola University Chicago, 2160 S. 1st Ave. Maywood, IL 60153,
| | - Sean Yamakawa
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Ibrahim Tahtah
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Jordan J. Sell
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Michael Broman
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, IL
| | - Brigitte Laforest
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, IL
| | - Sloane Harris
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Alejandro A. Alvarez
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Kelly N. Araujo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Megan J. Puckelwartz
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - J. Andrew Wasserstrom
- Department of Medicine and The Feinberg Cardiovascular and Renal Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Glenn I. Fishman
- Division of Cardiology, NYU Grossman School of Medicine, New York, New York
| | - Elizabeth M. McNally
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL;,Correspondence to: Elizabeth McNally, MD, PhD, Center for Genetic Medicine, Northwestern University, 303 E. Superior St. Chicago, IL 60611,
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18
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Alcalde M, Nogué-Navarro L, Tiron C, Fernandez-Falgueras A, Iglesias A, Simon A, Buxó M, Pérez-Serra A, Puigmulé M, López L, Picó F, del Olmo B, Corona M, Campuzano O, Moral S, Castella J, Coll M, Brugada R. Rare variants in genes encoding structural myocyte contribute to a thickened ventricular septum in sudden death population without ventricular alterations. Forensic Sci Int Genet 2022; 58:102688. [PMID: 35316720 DOI: 10.1016/j.fsigen.2022.102688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/08/2022] [Accepted: 03/12/2022] [Indexed: 01/09/2023]
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19
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Norrish G, Ding T, Field E, Cervi E, Ziółkowska L, Olivotto I, Khraiche D, Limongelli G, Anastasakis A, Weintraub R, Biagini E, Ragni L, Prendiville T, Duignan S, McLeod K, Ilina M, Fernández A, Marrone C, Bökenkamp R, Baban A, Kubus P, Daubeney PEF, Sarquella-Brugada G, Cesar S, Klaassen S, Ojala TH, Bhole V, Medrano C, Uzun O, Brown E, Gran F, Sinagra G, Castro FJ, Stuart G, Vignati G, Yamazawa H, Barriales-Villa R, Garcia-Guereta L, Adwani S, Linter K, Bharucha T, Garcia-Pavia P, Siles A, Rasmussen TB, Calcagnino M, Jones CB, De Wilde H, Kubo T, Felice T, Popoiu A, Mogensen J, Mathur S, Centeno F, Reinhardt Z, Schouvey S, O'Mahony C, Omar RZ, Elliott PM, Kaski JP. Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy. Circ Arrhythm Electrophysiol 2022; 15:e010075. [PMID: 35491873 PMCID: PMC7612749 DOI: 10.1161/circep.121.010075] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort. METHODS The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids). RESULTS MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk. CONCLUSIONS In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.
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Affiliation(s)
- Gabrielle Norrish
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., E.C., J.P.K.).,Institute of Cardiovascular Sciences (G.N., C.O., P.M.E., J.P.K.), University College London, United Kingdom
| | - Tao Ding
- Department of Statistical Science (T.D., R.Z.O.), University College London, United Kingdom
| | - Ella Field
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., E.C., J.P.K.)
| | - Elena Cervi
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., E.C., J.P.K.)
| | | | | | | | | | | | | | - Elena Biagini
- Cardiology Unit, S. Orsola-Malpighi Hospital, IRCCS Azienda Ospedalierao-Universitaria di Bologna, Italy (E.B., L.R.)
| | - Luca Ragni
- Cardiology Unit, S. Orsola-Malpighi Hospital, IRCCS Azienda Ospedalierao-Universitaria di Bologna, Italy (E.B., L.R.)
| | | | - Sophie Duignan
- Royal Hospital for Children, Glasgow, United Kingdom (K.M., M.I.)
| | - Karen McLeod
- Royal Hospital for Children, Glasgow, United Kingdom (K.M., M.I.)
| | - Maria Ilina
- Royal Hospital for Children, Glasgow, United Kingdom (K.M., M.I.)
| | - Adrián Fernández
- Fundación Favaloro University Hospital, Buenos Aires, Argentina (A.F.)
| | | | | | | | - Peter Kubus
- University Hospital Motol, Prague, Czech Republic (P.K.)
| | - Piers E F Daubeney
- Royal Brompton and Harefield NHS Trust, London, United Kingdom (P.E.F.D.)
| | | | - Sergi Cesar
- Sant Joan de Deu, Barcelona, Spain (G.S.-B., S.C.)
| | - Sabine Klaassen
- Department of Pediatric Cardiology (S.K.), Charite-Universitatsmedizin Berlin, Germany.,Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück-Center for Molecular Medicine (S.K.), Charite-Universitatsmedizin Berlin, Germany.,German Centre for Cardiovascular Research, Partner Site Berlin, Germany (S.K.)
| | - Tiina H Ojala
- Department of Pediatric Cardiology, Pediatric Research Center, New Children's Hospital, University of Helsinki, Finland (T.H.O.)
| | - Vinay Bhole
- Birmingham Children's Hospital, United Kingdom (V.B.)
| | - Constancio Medrano
- Fondazione Toscana G. Monasterio, Massa-Pisa, Italy (C.M.).,Hospital General Universitario Gregorio Marañón, Madrid, Spain (C.M.)
| | - Orhan Uzun
- University Hospital of Wales, Cardiff (O.U.)
| | | | - Ferran Gran
- Val d'Hebron University Hospital, Barcelona, Spain (F.G.)
| | - Gianfranco Sinagra
- Heart Muscle Disease Registry Trieste, University of Trieste, Italy (G.S.)
| | | | - Graham Stuart
- Bristol Royal Hospital for Children, United Kingdom (G.S.)
| | | | - Hirokuni Yamazawa
- Department of Pediatrics, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Hospital, Sapporo, Japan (H.Y.)
| | | | | | | | | | - Tara Bharucha
- Southampton General Hospital, Southampton, United Kingdom (T.B.)
| | - Pablo Garcia-Pavia
- Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain (P.G.-P., A.S.)
| | - Ana Siles
- Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain (P.G.-P., A.S.)
| | | | - Margherita Calcagnino
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milano, Dept di Medicina Interna, UOC Cardiologica, Milano, Italy (M.C.)
| | - Caroline B Jones
- Alder Hey Children's Hospital, Liverpool, United Kingdom (C.B.J.)
| | | | - Toru Kubo
- Kochi Medical School Hospital, Japan (T.K.)
| | | | - Anca Popoiu
- Department of Pediatrics, University of Medicine and Pharmacy "Victor Babes" Timisoara, Children's Hospital 'Louis Turcanu,' Romania (A.P.)
| | | | - Sujeev Mathur
- Evelina Children's Hospital, London, United Kingdom (S.M.)
| | | | | | | | - Costas O'Mahony
- Institute of Cardiovascular Sciences (G.N., C.O., P.M.E., J.P.K.), University College London, United Kingdom.,St Bartholomew's Centre for Inherited Cardiovascular Diseases, St Bartholomew's Hospital, West Smithfield, London, United Kingdom (C.O., P.M.E.)
| | - Rumana Z Omar
- Department of Statistical Science (T.D., R.Z.O.), University College London, United Kingdom
| | - Perry M Elliott
- Institute of Cardiovascular Sciences (G.N., C.O., P.M.E., J.P.K.), University College London, United Kingdom.,St Bartholomew's Centre for Inherited Cardiovascular Diseases, St Bartholomew's Hospital, West Smithfield, London, United Kingdom (C.O., P.M.E.)
| | - Juan Pablo Kaski
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., E.C., J.P.K.).,Institute of Cardiovascular Sciences (G.N., C.O., P.M.E., J.P.K.), University College London, United Kingdom
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20
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Bourque K, Hawey C, Jiang A, Mazarura GR, Hébert TE. Biosensor-based profiling to track cellular signalling in patient-derived models of dilated cardiomyopathy. Cell Signal 2022; 91:110239. [PMID: 34990783 DOI: 10.1016/j.cellsig.2021.110239] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/06/2021] [Accepted: 12/29/2021] [Indexed: 12/18/2022]
Abstract
Dilated cardiomyopathies (DCM) represent a diverse group of cardiovascular diseases impacting the structure and function of the myocardium. To better treat these diseases, we need to understand the impact of such cardiomyopathies on critical signalling pathways that drive disease progression downstream of receptors we often target therapeutically. Our understanding of cellular signalling events has progressed substantially in the last few years, in large part due to the design, validation and use of biosensor-based approaches to studying such events in cells, tissues and in some cases, living animals. Another transformative development has been the use of human induced pluripotent stem cells (hiPSCs) to generate disease-relevant models from individual patients. We highlight the importance of going beyond monocellular cultures to incorporate the influence of paracrine signalling mediators. Finally, we discuss the recent coalition of these approaches in the context of DCM. We discuss recent work in generating patient-derived models of cardiomyopathies and the utility of using signalling biosensors to track disease progression and test potential therapeutic strategies that can be later used to inform treatment options in patients.
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Affiliation(s)
- Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Cara Hawey
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Alyson Jiang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Grace R Mazarura
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
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21
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Shafaattalab S, Li AY, Gunawan MG, Kim B, Jayousi F, Maaref Y, Song Z, Weiss JN, Solaro RJ, Qu Z, Tibbits GF. Mechanisms of Arrhythmogenicity of Hypertrophic Cardiomyopathy-Associated Troponin T ( TNNT2) Variant I79N. Front Cell Dev Biol 2022; 9:787581. [PMID: 34977031 PMCID: PMC8718794 DOI: 10.3389/fcell.2021.787581] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common heritable cardiovascular disease and often results in cardiac remodeling and an increased incidence of sudden cardiac arrest (SCA) and death, especially in youth and young adults. Among thousands of different variants found in HCM patients, variants of TNNT2 (cardiac troponin T—TNNT2) are linked to increased risk of ventricular arrhythmogenesis and sudden death despite causing little to no cardiac hypertrophy. Therefore, studying the effect of TNNT2 variants on cardiac propensity for arrhythmogenesis can pave the way for characterizing HCM in susceptible patients before sudden cardiac arrest occurs. In this study, a TNNT2 variant, I79N, was generated in human cardiac recombinant/reconstituted thin filaments (hcRTF) to investigate the effect of the mutation on myofilament Ca2+ sensitivity and Ca2+ dissociation rate using steady-state and stopped-flow fluorescence techniques. The results revealed that the I79N variant significantly increases myofilament Ca2+ sensitivity and decreases the Ca2+ off-rate constant (koff). To investigate further, a heterozygous I79N+/−TNNT2 variant was introduced into human-induced pluripotent stem cells using CRISPR/Cas9 and subsequently differentiated into ventricular cardiomyocytes (hiPSC-CMs). To study the arrhythmogenic properties, monolayers of I79N+/− hiPSC-CMs were studied in comparison to their isogenic controls. Arrhythmogenesis was investigated by measuring voltage (Vm) and cytosolic Ca2+ transients over a range of stimulation frequencies. An increasing stimulation frequency was applied to the cells, from 55 to 75 bpm. The results of this protocol showed that the TnT-I79N cells had reduced intracellular Ca2+ transients due to the enhanced cytosolic Ca2+ buffering. These changes in Ca2+ handling resulted in beat-to-beat instability and triangulation of the cardiac action potential, which are predictors of arrhythmia risk. While wild-type (WT) hiPSC-CMs were accurately entrained to frequencies of at least 150 bpm, the I79N hiPSC-CMs demonstrated clear patterns of alternans for both Vm and Ca2+ transients at frequencies >75 bpm. Lastly, a transcriptomic analysis was conducted on WT vs. I79N+/−TNNT2 hiPSC-CMs using a custom NanoString codeset. The results showed a significant upregulation of NPPA (atrial natriuretic peptide), NPPB (brain natriuretic peptide), Notch signaling pathway components, and other extracellular matrix (ECM) remodeling components in I79N+/− vs. the isogenic control. This significant shift demonstrates that this missense in the TNNT2 transcript likely causes a biophysical trigger, which initiates this significant alteration in the transcriptome. This TnT-I79N hiPSC-CM model not only reproduces key cellular features of HCM-linked mutations but also suggests that this variant causes uncharted pro-arrhythmic changes to the human action potential and gene expression.
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Affiliation(s)
- Sanam Shafaattalab
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Alison Y Li
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Marvin G Gunawan
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - BaRun Kim
- Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Farah Jayousi
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Yasaman Maaref
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Zhen Song
- UCLA Cardiac Computation Lab, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - James N Weiss
- UCLA Cardiac Computation Lab, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - R John Solaro
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
| | - Zhilin Qu
- UCLA Cardiac Computation Lab, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Glen F Tibbits
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cellular and Regenerative Medicine Centre, BC Children's Hospital Research Institute, Vancouver, BC, Canada.,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.,Department of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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22
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Abstract
PURPOSE OF REVIEW Hypertrophic cardiomyopathy (HCM) is one of the leading causes of sudden cardiac death (SCD) in younger people and athletes. It is crucial to identify the risk factors for SCD in individuals with HCM. This review, based on recent systematic literature studies, will focus on the risk factors for SCD in patients with HCM. RECENT FINDINGS An increasing number of studies have further explored the risk factors for SCD in patients with HCM, and new risk markers have emerged accordingly. In addition, more accurate SCD risk estimation and stratification methods have been proposed and continuously improved. SUMMARY The identification of independent risk factors for HCM-related SCD would likely contribute to risk stratification. However, it is difficult to predict SCD with absolute certainty, as the annual incidence of SCD in adult patients with HCM is approximately 1%. The review discusses the established risk factors, such as a family history of SCD, unexplained syncope and some new risk factors. Taken together, the findings of this review demonstrate that there is a need for further research on individual risk factors and that SCD risk stratification in HCM patients remains a clinical challenge.
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Affiliation(s)
- Ying Hong
- Department of Cardiology, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
- Department of Cardiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China
| | - Wilber W. Su
- Department of Cardiology, Banner-University Medical Center, Phoenix, Arizona, USA
| | - Xiaoping Li
- Department of Cardiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China
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23
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Pollmann K, Kaltenecker E, Schleihauf J, Ewert P, Görlach A, Wolf CM. Compound Mutation in Cardiac Sarcomere Proteins Is Associated with Increased Risk for Major Arrhythmic Events in Pediatric Onset Hypertrophic Cardiomyopathy. J Clin Med 2021; 10:jcm10225256. [PMID: 34830538 PMCID: PMC8617951 DOI: 10.3390/jcm10225256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/02/2021] [Accepted: 11/09/2021] [Indexed: 12/14/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is associated with adverse left ventricular (LV) remodeling causing dysfunction and malignant arrhythmias. Severely affected patients present with disease onset during childhood and sudden cardiac death risk (SCD) stratification is of the highest importance in this cohort. This study aimed to investigate genotype–phenotype association regarding clinical outcome and disease progression in pediatric onset HCM. Medical charts from forty-nine patients with pediatric HCM who had undergone genetic testing were reviewed for retrospective analysis. Demographic, clinical, transthoracic echocardiographic, electrocardiographic, long-term electrocardiogram, cardiopulmonary exercise test, cardiac magnetic resonance, and medication data were recorded. Childhood onset HCM was diagnosed in 29 males and 20 females. Median age at last follow-up was 18.7 years (range 2.6–51.7 years) with a median follow-up time since diagnosis of 8.5 years (range 0.2–38.0 years). Comparison of patients carrying mutations in distinct genes and comparison of genotype-negative with genotype-positive individuals, revealed no differences in functional classification, LV morphology, hypertrophy, systolic and diastolic function, fibrosis and cardiac medication. Patients with compound mutations had a significantly higher risk for major arrhythmic events than a single-mutation carrier. No association between affected genes and disease severity or progression was identified in this cohort.
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Affiliation(s)
- Kathrin Pollmann
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
| | - Emanuel Kaltenecker
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
| | - Julia Schleihauf
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
| | - Peter Ewert
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80802 Munich, Germany
| | - Agnes Görlach
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80802 Munich, Germany
- Experimental and Molecular Pediatric Cardiology, Technical University of Munich, 80636 Munich, Germany
| | - Cordula M. Wolf
- German Heart Center Munich, Department of Congenital Heart Disease and Pediatric Cardiology, School of Medicine & Health, Technical University of Munich, 80636 Munich, Germany; (K.P.); (E.K.); (J.S.); (P.E.); (A.G.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80802 Munich, Germany
- Correspondence:
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24
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Ion Channel Impairment and Myofilament Ca 2+ Sensitization: Two Parallel Mechanisms Underlying Arrhythmogenesis in Hypertrophic Cardiomyopathy. Cells 2021; 10:cells10102789. [PMID: 34685769 PMCID: PMC8534456 DOI: 10.3390/cells10102789] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/07/2021] [Accepted: 10/13/2021] [Indexed: 11/17/2022] Open
Abstract
Life-threatening ventricular arrhythmias are the main clinical burden in patients with hypertrophic cardiomyopathy (HCM), and frequently occur in young patients with mild structural disease. While massive hypertrophy, fibrosis and microvascular ischemia are the main mechanisms underlying sustained reentry-based ventricular arrhythmias in advanced HCM, cardiomyocyte-based functional arrhythmogenic mechanisms are likely prevalent at earlier stages of the disease. In this review, we will describe studies conducted in human surgical samples from HCM patients, transgenic animal models and human cultured cell lines derived from induced pluripotent stem cells. Current pieces of evidence concur to attribute the increased risk of ventricular arrhythmias in early HCM to different cellular mechanisms. The increase of late sodium current and L-type calcium current is an early observation in HCM, which follows post-translation channel modifications and increases the occurrence of early and delayed afterdepolarizations. Increased myofilament Ca2+ sensitivity, commonly observed in HCM, may promote afterdepolarizations and reentry arrhythmias with direct mechanisms. Decrease of K+-currents due to transcriptional regulation occurs in the advanced disease and contributes to reducing the repolarization-reserve and increasing the early afterdepolarizations (EADs). The presented evidence supports the idea that patients with early-stage HCM should be considered and managed as subjects with an acquired channelopathy rather than with a structural cardiac disease.
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25
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Bonaventura J, Polakova E, Vejtasova V, Veselka J. Genetic Testing in Patients with Hypertrophic Cardiomyopathy. Int J Mol Sci 2021; 22:10401. [PMID: 34638741 PMCID: PMC8509044 DOI: 10.3390/ijms221910401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/17/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited heart disease with an estimated prevalence of up to 1 in 200 individuals. In the majority of cases, HCM is considered a Mendelian disease, with mainly autosomal dominant inheritance. Most pathogenic variants are usually detected in genes for sarcomeric proteins. Nowadays, the genetic basis of HCM is believed to be rather complex. Thousands of mutations in more than 60 genes have been described in association with HCM. Nevertheless, screening large numbers of genes results in the identification of many genetic variants of uncertain significance and makes the interpretation of the results difficult. Patients lacking a pathogenic variant are now believed to have non-Mendelian HCM and probably have a better prognosis than patients with sarcomeric pathogenic mutations. Identifying the genetic basis of HCM creates remarkable opportunities to understand how the disease develops, and by extension, how to disrupt the disease progression in the future. The aim of this review is to discuss the brief history and recent advances in the genetics of HCM and the application of molecular genetic testing into common clinical practice.
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Affiliation(s)
- Jiri Bonaventura
- Department of Cardiology, Motol University Hospital, 2nd Faculty of Medicine, Charles University, V Uvalu 84, 15006 Prague, Czech Republic; (E.P.); (V.V.); (J.V.)
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26
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Finocchiaro G, Sheikh N, Leone O, Westaby J, Mazzarotto F, Pantazis A, Ferrantini C, Sacconi L, Papadakis M, Sharma S, Sheppard MN, Olivotto I. Arrhythmogenic potential of myocardial disarray in hypertrophic cardiomyopathy: genetic basis, functional consequences and relation to sudden cardiac death. Europace 2021; 23:985-995. [PMID: 33447843 DOI: 10.1093/europace/euaa348] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 10/28/2020] [Indexed: 12/19/2022] Open
Abstract
Myocardial disarray is defined as disorganized cardiomyocyte spatial distribution, with loss of physiological fibre alignment and orientation. Since the first pathological descriptions of hypertrophic cardiomyopathy (HCM), disarray appeared as a typical feature of this condition and sparked vivid debate regarding its specificity to the disease and clinical significance as a diagnostic marker and a risk factor for sudden death. Although much of the controversy surrounding its diagnostic value in HCM persists, it is increasingly recognized that myocardial disarray may be found in physiological contexts and in cardiac conditions different from HCM, raising the possibility that central focus should be placed on its quantity and distribution, rather than a mere presence. While further studies are needed to establish what amount of disarray should be considered as a hallmark of the disease, novel experimental approaches and emerging imaging techniques for the first time allow ex vivo and in vivo characterization of the myocardium to a molecular level. Such advances hold the promise of filling major gaps in our understanding of the functional consequences of myocardial disarray in HCM and specifically on arrhythmogenic propensity and as a risk factor for sudden death. Ultimately, these studies will clarify whether disarray represents a major determinant of the HCM clinical profile, and a potential therapeutic target, as opposed to an intriguing but largely innocent bystander.
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Affiliation(s)
- Gherardo Finocchiaro
- Cardiothoracic Centre, Guy's and St Thomas' Hospital, London, UK.,King's College London
| | - Nabeel Sheikh
- Cardiothoracic Centre, Guy's and St Thomas' Hospital, London, UK.,King's College London
| | - Ornella Leone
- Cardiovascular and Cardiac Transplant Pathology Unit, Department of Pathology, Sant'Orsola-Malpighi University Hospital, Bologna, Italy
| | - Joe Westaby
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Francesco Mazzarotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy.,Department of Experimental and Clinical Medicine, University of Florence, Italy.,National Heart and Lung Institute, Imperial College London, UK.,Cardiovascular Research Centre, Royal Brompton and Harefield National Health Service Foundation Trust, London, UK
| | - Antonis Pantazis
- Cardiovascular Research Centre, Royal Brompton and Harefield National Health Service Foundation Trust, London, UK
| | - Cecilia Ferrantini
- University of Florence, Florence, Italy.,European Laboratory for Non-Linear Spectroscopy, Florence, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, Florence, Italy.,Institute for Experimental Cardiovascular Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Papadakis
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Sanjay Sharma
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Mary N Sheppard
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Iacopo Olivotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy
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27
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Leong KMW, Ng FS, Shun-Shin MJ, Koa-Wing M, Qureshi N, Whinnett ZI, Linton NF, Lefroy D, Francis DP, Harding SE, Davies DW, Peter NS, Lim PB, Behr E, Lambiase PD, Varnava A, Kanagaratnam P. Non-invasive detection of exercise-induced cardiac conduction abnormalities in sudden cardiac death survivors in the inherited cardiac conditions. Europace 2021; 23:305-312. [PMID: 33083839 DOI: 10.1093/europace/euaa248] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 08/18/2020] [Indexed: 11/12/2022] Open
Abstract
AIMS Rate adaptation of the action potential ensures spatial heterogeneities in conduction across the myocardium are minimized at different heart rates providing a protective mechanism against ventricular fibrillation (VF) and sudden cardiac death (SCD), which can be quantified by the ventricular conduction stability (V-CoS) test previously described. We tested the hypothesis that patients with a history of aborted SCD due to an underlying channelopathy or cardiomyopathy have a reduced capacity to maintain uniform activation following exercise. METHODS AND RESULTS Sixty individuals, with (n = 28) and without (n = 32) previous aborted-SCD event underwent electro-cardiographic imaging recordings following exercise treadmill test. These included 25 Brugada syndrome, 13 hypertrophic cardiomyopathy, 12 idiopathic VF, and 10 healthy controls. Data were inputted into the V-CoS programme to calculate a V-CoS score that indicate the percentage of ventricle that showed no significant change in ventricular activation, with a lower score indicating the development of greater conduction heterogeneity. The SCD group, compared to those without, had a lower median (interquartile range) V-CoS score at peak exertion [92.8% (89.8-96.3%) vs. 97.3% (94.9-99.1%); P < 0.01] and 2 min into recovery [95.2% (91.1-97.2%) vs. 98.9% (96.9-99.5%); P < 0.01]. No significant difference was observable later into recovery at 5 or 10 min. Using the lowest median V-CoS scores obtained during the entire recovery period post-exertion, SCD survivors had a significantly lower score than those without for each of the different underlying aetiologies. CONCLUSION Data from this pilot study demonstrate the potential use of this technique in risk stratification for the inherited cardiac conditions.
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Affiliation(s)
- Kevin Ming Wei Leong
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Fu Siong Ng
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Matthew J Shun-Shin
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Michael Koa-Wing
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Norman Qureshi
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Zachary I Whinnett
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Nick F Linton
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - David Lefroy
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Darrel P Francis
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Sian E Harding
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - D Wyn Davies
- Imperial College Healthcare NHS Trust, London, UK
| | - Nicholas S Peter
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Phang Boon Lim
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Elijah Behr
- St George's University Hospitals NHS Trust, London, UK
| | | | - Amanda Varnava
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
| | - Prapa Kanagaratnam
- Institute of Cardiovascular Science, University College London & Bart's Heart Centre, Bart's Health NHS Trust, London, UK.,Imperial College Healthcare NHS Trust, London, UK
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28
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Mani I. Genome editing in cardiovascular diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 181:289-308. [PMID: 34127197 DOI: 10.1016/bs.pmbts.2021.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Genetic modification at the molecular level in somatic cells, germline, and animal models requires for different purposes, such as introducing desired mutation, deletion of alleles, and insertion of novel genes in the genome. Various genome-editing tools are available to accomplish these alterations, such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated (Cas) system. CRISPR-Cas system is an emerging technology, which is being used in biological and medical sciences, including in the cardiovascular field. It assists to identify the mechanism of various cardiovascular disease occurrence, such as hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and arrhythmogenic cardiomyopathy (ACM). Furthermore, it has been advantages to edit various genes simultaneously and can also be used to treat and prevent several human diseases. This chapter explores the use of the scientific and therapeutic potential of a CRISPR-Cas system to edit the various cardiovascular disease-associated genes to understand the pathways involved in disease progression and treatment.
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Affiliation(s)
- Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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29
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Assessment of dynamic cardiac repolarization and contractility in patients with hypertrophic cardiomyopathy. PLoS One 2021; 16:e0246768. [PMID: 33571287 PMCID: PMC7877626 DOI: 10.1371/journal.pone.0246768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/25/2021] [Indexed: 11/24/2022] Open
Abstract
Aims Arrhythmia mechanisms in hypertrophic cardiomyopathy remain uncertain. Preclinical models suggest hypertrophic cardiomyopathy-linked mutations perturb sarcomere length-dependent activation, alter cardiac repolarization in rate-dependent fashion and potentiate triggered electrical activity. This study was designed to assess rate-dependence of clinical surrogates of contractility and repolarization in humans with hypertrophic cardiomyopathy. Methods All participants had a cardiac implantable device capable of atrial pacing. Cases had clinical diagnosis of hypertrophic cardiomyopathy, controls were age-matched. Continuous electrocardiogram and blood pressure were recorded during and immediately after 30 second pacing trains delivered at increasing rates. Results Nine hypertrophic cardiomyopathy patients and 10 controls were enrolled (47% female, median 55 years), with similar baseline QRS duration, QT interval and blood pressure. Median septal thickness in hypertrophic cardiomyopathy patients was 18mm; 33% of hypertrophic cardiomyopathy patients had peak sub-aortic velocity >50mmHg. Ventricular ectopy occurred during or immediately after pacing trains in 4/9 hypertrophic cardiomyopathy patients and 0/10 controls (P = 0.03). During delivery of steady rate pacing across a range of cycle lengths, the QT-RR relationship was not statistically different between HCM and control groups; no differences were seen in subgroup analysis of patients with or without intact AV node conduction. Similarly, there was no difference between groups in the QT interval of the first post-pause recovery beat after pacing trains. No statistically significant differences were seen in surrogate measures for cardiac contractility. Conclusion Rapid pacing trains triggered ventricular ectopy in hypertrophic cardiomyopathy patients, but not controls. This finding aligns with pre-clinical descriptions of excessive cardiomyocyte calcium loading during rapid pacing, increased post-pause sarcoplasmic reticulum calcium release, and subsequent calcium-triggered activity. Normal contractility at all diastolic intervals argues against clinical significance of altered length-dependent myofilament activation.
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30
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Hypertrophic Cardiomyopathy: Diverse Pathophysiology Revealed by Genetic Research, Toward Future Therapy. Keio J Med 2020; 69:77-87. [PMID: 32224552 DOI: 10.2302/kjm.2019-0012-oa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is an intractable disease that causes heart failure mainly due to unexplained severe cardiac hypertrophy and diastolic dysfunction. HCM, which occurs in 0.2% of the general population, is the most common cause of sudden cardiac death in young people. HCM has been studied extensively using molecular genetic approaches. Genes encoding cardiac β-myosin heavy chain, cardiac myosin-binding protein C, and troponin complex, which were originally identified as causative genes, were subsequently reported to be frequently implicated in HCM. Indeed, HCM has been considered a disease of sarcomere gene mutations. However, fewer than half of patients with HCM have mutations in sarcomere genes. The others have been documented to have mutations in cardiac proteins in various other locations, including the Z disc, sarcoplasmic reticulum, plasma membrane, nucleus, and mitochondria. Next-generation sequencing makes it possible to detect mutations at high throughput, and it has become increasingly common to identify multiple cardiomyopathy-causing gene mutations in a single HCM patient. Elucidating how mutations in different genes contribute to the disease pathophysiology will be a challenge. In studies using animal models, sarcomere mutations generally tend to increase myocardial Ca2+ sensitivity, and some mutations increase the activity of myosin ATPase. Clinical trials of drugs to treat HCM are ongoing, and further new therapies based on pathophysiological analyses of the causative genes are eagerly anticipated.
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31
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Post-Mortem Cardiac Magnetic Resonance for the Diagnosis of Hypertrophic Cardiomyopathy. Diagnostics (Basel) 2020; 10:diagnostics10110981. [PMID: 33233445 PMCID: PMC7700290 DOI: 10.3390/diagnostics10110981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/04/2022] Open
Abstract
Background: Post-mortem cardiac magnetic resonance (PMCMR) is an emerging tool supporting forensic medicine for the identification of the causes of cardiac death, such as hypertrophic cardiomyopathy (HCM). We proposed a new method of PMCMR to diagnose HCM despite myocardial rigor mortis. Methods: We performed CMR in 49 HCM patients, 30 non-HCM hypertrophy, and 32 healthy controls. In cine images, rigor mortis was simulated by the analysis of the cardiac phase corresponding to 25% of diastole. Left ventricular mass, mean, and standard deviation (SD) of WT, maximal WT, minimal WT, and their difference were compared for the identification of HCM. These parameters were validated at PMCMR, evaluating eight hearts with HCM, 10 with coronary artery disease, and 10 with non-cardiac death. Results: The SD of WT with a cut-off of > 2.4 had the highest accuracy to identify HCM (AUC 0.95, 95% CI = 0.89–0.98). This was particularly evident in the female population of HCM (AUC=0.998), with 100% specificity (95% CI = 85–100%) and 96% sensitivity (95% CI = 79–99%). Using this parameter, at PMCMR, all of the eight patients with HCM were correctly identified with no false positives. Conclusions: PMCMR allows identification of HCM as the cause of sudden death using the SD of WT > 2.4 as the diagnostic parameter.
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Santini L, Palandri C, Nediani C, Cerbai E, Coppini R. Modelling genetic diseases for drug development: Hypertrophic cardiomyopathy. Pharmacol Res 2020; 160:105176. [DOI: 10.1016/j.phrs.2020.105176] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/16/2020] [Accepted: 08/22/2020] [Indexed: 12/13/2022]
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Ariga R, Tunnicliffe EM, Manohar SG, Mahmod M, Raman B, Piechnik SK, Francis JM, Robson MD, Neubauer S, Watkins H. Identification of Myocardial Disarray in Patients With Hypertrophic Cardiomyopathy and Ventricular Arrhythmias. J Am Coll Cardiol 2020; 73:2493-2502. [PMID: 31118142 PMCID: PMC6548973 DOI: 10.1016/j.jacc.2019.02.065] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 02/07/2019] [Accepted: 02/26/2019] [Indexed: 01/26/2023]
Abstract
Background Myocardial disarray is a likely focus for fatal arrhythmia in hypertrophic cardiomyopathy (HCM). This microstructural abnormality can be inferred by mapping the preferential diffusion of water along cardiac muscle fibers using diffusion tensor cardiac magnetic resonance (DT-CMR) imaging. Fractional anisotropy (FA) quantifies directionality of diffusion in 3 dimensions. The authors hypothesized that FA would be reduced in HCM due to disarray and fibrosis that may represent the anatomic substrate for ventricular arrhythmia. Objectives This study sought to assess FA as a noninvasive in vivo biomarker of HCM myoarchitecture and its association with ventricular arrhythmia. Methods A total of 50 HCM patients (47 ± 15 years of age, 77% male) and 30 healthy control subjects (46 ± 16 years of age, 70% male) underwent DT-CMR in diastole, cine, late gadolinium enhancement (LGE), and extracellular volume (ECV) imaging at 3-T. Results Diastolic FA was reduced in HCM compared with control subjects (0.49 ± 0.05 vs. 0.52 ± 0.03; p = 0.0005). Control subjects had a mid-wall ring of high FA. In HCM, this ring was disrupted by reduced FA, consistent with published histology demonstrating that disarray and fibrosis invade circumferentially aligned mid-wall myocytes. LGE and ECV were significant predictors of FA, in line with fibrosis contributing to low FA. Yet FA adjusted for LGE and ECV remained reduced in HCM (p = 0.028). FA in the hypertrophied segment was reduced in HCM patients with ventricular arrhythmia compared to patients without (n = 15; 0.41 ± 0.03 vs. 0.46 ± 0.06; p = 0.007). A decrease in FA of 0.05 increased odds of ventricular arrhythmia by 2.5 (95% confidence interval: 1.2 to 5.3; p = 0.015) in HCM and remained significant even after correcting for LGE, ECV, and wall thickness (p = 0.036). Conclusions DT-CMR assessment of left ventricular myoarchitecture matched patterns reported previously on histology. Low diastolic FA in HCM was associated with ventricular arrhythmia and is likely to represent disarray after accounting for fibrosis. The authors propose that diastolic FA could be the first in vivo marker of disarray in HCM and a potential independent risk factor.
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Affiliation(s)
- Rina Ariga
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Elizabeth M Tunnicliffe
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sanjay G Manohar
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Masliza Mahmod
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Betty Raman
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stefan K Piechnik
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jane M Francis
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Matthew D Robson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
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Sukhacheva TV, Serov RA, Bockeria LA. [Hypertrophic cardiomyopathy. Cardiomyocyte ultrastructure, the specific or stereotypic signs]. Arkh Patol 2019; 81:5-15. [PMID: 31851187 DOI: 10.17116/patol2019810615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a congenital disease caused by mutations in a number of sarcomere proteins. According to the type of mutation, clinical observations record similar clinical manifestations, myocardial pathological changes, and the timing of manifestation of the disease in HCM patients. OBJECTIVE To study cardiomyocyte (CMC) ultrastructural changes in the interventricular septum (IVS) of patients with HCM and evaluate their specificity for this pathology. MATERIAL AND METHODS IVS myocardial samples taken from 44 HCM patients aged 18-59 years at IVS myoectomy underwent an electron microscopic study. The diameter of CMCs and their nuclei was measured in semithin sections. RESULTS A morphometric examination of the IVS myocardium in HCM patients revealed moderate hypertrophy of CMCs and their nuclei, the diameters of which averaged 23.7±4.4 and 5.2±0.9 μm, respectively. The IVS CMCs were characterized by the ultrastructural signs of hypertrophy: the larger size and number of structures ensuring contractile and synthetic functions; the myocytes contained higher amounts of myofibrils, intermyofibrillar mitochondria, granular endoplasmic reticulum cisterns, and free ribosomes. On the contrary, some CMCs had fewer myofibrils in the perinuclear region, which is an adaptive change under hemodynamic overload conditions. In addition, a number of myocytes displayed signs of dystrophic changes: the appearance of lipofuscin granules, myelin figures, phagosomes, lipid droplets, and vacuoles, which can fill all free sarcoplasmic zones. CONCLUSION Ultrastructural changes characteristic of hypertrophy were found in IVS CMCs in HCM patients. In addition, there was partial myofibrillar loss and dystrophic changes in a number of myocytes, which are stereotypic compensatory-adaptive changes under hemodynamic overload conditions. All the above-mentioned changes in the CMC ultrastructure are characteristic of myocardial hypertrophy, but not specific for hypertrophic cardiomyopathy.
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Affiliation(s)
- T V Sukhacheva
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
| | - R A Serov
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
| | - L A Bockeria
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
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Liu Y, Afzal J, Vakrou S, Greenland GV, Talbot CC, Hebl VB, Guan Y, Karmali R, Tardiff JC, Leinwand LA, Olgin JE, Das S, Fukunaga R, Abraham MR. Differences in microRNA-29 and Pro-fibrotic Gene Expression in Mouse and Human Hypertrophic Cardiomyopathy. Front Cardiovasc Med 2019; 6:170. [PMID: 31921893 PMCID: PMC6928121 DOI: 10.3389/fcvm.2019.00170] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/08/2019] [Indexed: 12/11/2022] Open
Abstract
Background: Hypertrophic cardiomyopathy (HCM) is characterized by myocyte hypertrophy and fibrosis. Studies in two mouse models (R92W-TnT/R403Q-MyHC) at early HCM stage revealed upregulation of endothelin (ET1) signaling in both mutants, but TGFβ signaling only in TnT mutants. Dysregulation of miR-29 expression has been implicated in cardiac fibrosis. But it is unknown whether expression of miR-29a/b/c and profibrotic genes is commonly regulated in mouse and human HCM. Methods: In order to understand mechanisms underlying fibrosis in HCM, and examine similarities/differences in expression of miR-29a/b/c and several profibrotic genes in mouse and human HCM, we performed parallel studies in rat cardiac myocyte/fibroblast cultures, examined gene expression in two mouse models of (non-obstructive) HCM (R92W-TnT, R403Q-MyHC)/controls at early (5 weeks) and established (24 weeks) disease stage, and analyzed publicly available mRNA/miRNA expression data from obstructive-HCM patients undergoing septal myectomy/controls (unused donor hearts). Results: Myocyte cultures: ET1 increased superoxide/H2O2, stimulated TGFβ expression/secretion, and suppressed miR-29a expression in myocytes. The effect of ET1 on miR-29 and TGFβ expression/secretion was antagonized by N-acetyl-cysteine, a reactive oxygen species scavenger. Fibroblast cultures: ET1 had no effect on pro-fibrotic gene expression in fibroblasts. TGFβ1/TGFβ2 suppressed miR-29a and increased collagen expression, which was abolished by miR-29a overexpression. Mouse and human HCM: Expression of miR-29a/b/c was lower, and TGFB1/collagen gene expression was higher in TnT mutant-LV at 5 and 24 weeks; no difference was observed in expression of these genes in MyHC mutant-LV and in human myectomy tissue. TGFB2 expression was higher in LV of both mutant mice and human myectomy tissue. ACE2, a negative regulator of the renin-angiotensin-aldosterone system, was the most upregulated transcript in human myectomy tissue. Pathway analysis predicted upregulation of the anti-hypertrophic/anti-fibrotic liver X receptor/retinoid X receptor (LXR/RXR) pathway only in human myectomy tissue. Conclusions: Our in vitro studies suggest that activation of ET1 signaling in cardiac myocytes increases reactive oxygen species and stimulates TGFβ secretion, which downregulates miR-29a and increases collagen in fibroblasts, thus contributing to fibrosis. Our gene expression studies in mouse and human HCM reveal allele-specific differences in miR-29 family/profibrotic gene expression in mouse HCM, and activation of anti-hypertrophic/anti-fibrotic genes and pathways in human HCM.
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Affiliation(s)
- Yamin Liu
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States.,Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
| | - Junaid Afzal
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States.,Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
| | - Styliani Vakrou
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
| | - Gabriela V Greenland
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States.,Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
| | - C Conover Talbot
- Johns Hopkins School of Medicine, Institute for Basic Biomedical Sciences, Baltimore, MD, United States
| | - Virginia B Hebl
- Intermountain Medical Center, Intermountain Heart Institute, Murray, UT, United States
| | - Yufan Guan
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
| | - Rehan Karmali
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States
| | - Jil C Tardiff
- Sarver Heart Center, University of Arizona Health Sciences, Tucson, AZ, United States
| | - Leslie A Leinwand
- Molecular, Cellular and Developmental Biology, Biofrontiers Institute, University of Colorado, Boulder, CO, United States
| | - Jeffrey E Olgin
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States
| | - Samarjit Das
- Department of Anesthesia and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Ryuya Fukunaga
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - M Roselle Abraham
- Division of Cardiology, Hypertrophic Cardiomyopathy Center of Excellence, University of California, San Francisco, San Francisco, CA, United States.,Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, MD, United States
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Abdullah S, Lynn ML, McConnell MT, Klass MM, Baldo AP, Schwartz SD, Tardiff JC. FRET-based analysis of the cardiac troponin T linker region reveals the structural basis of the hypertrophic cardiomyopathy-causing Δ160E mutation. J Biol Chem 2019; 294:14634-14647. [PMID: 31387947 DOI: 10.1074/jbc.ra118.005098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 07/12/2019] [Indexed: 11/06/2022] Open
Abstract
Mutations in the cardiac thin filament (TF) have highly variable effects on the regulatory function of the cardiac sarcomere. Understanding the molecular-level dysfunction elicited by TF mutations is crucial to elucidate cardiac disease mechanisms. The hypertrophic cardiomyopathy-causing cardiac troponin T (cTnT) mutation Δ160Glu (Δ160E) is located in a putative "hinge" adjacent to an unstructured linker connecting domains TNT1 and TNT2. Currently, no high-resolution structure exists for this region, limiting significantly our ability to understand its role in myofilament activation and the molecular mechanism of mutation-induced dysfunction. Previous regulated in vitro motility data have indicated mutation-induced impairment of weak actomyosin interactions. We hypothesized that cTnT-Δ160E repositions the flexible linker, altering weak actomyosin electrostatic binding and acting as a biophysical trigger for impaired contractility and the observed remodeling. Using time-resolved FRET and an all-atom TF model, here we first defined the WT structure of the cTnT-linker region and then identified Δ160E mutation-induced positional changes. Our results suggest that the WT linker runs alongside the C terminus of tropomyosin. The Δ160E-induced structural changes moved the linker closer to the tropomyosin C terminus, an effect that was more pronounced in the presence of myosin subfragment (S1) heads, supporting previous findings. Our in silico model fully supported this result, indicating a mutation-induced decrease in linker flexibility. Our findings provide a framework for understanding basic pathogenic mechanisms that drive severe clinical hypertrophic cardiomyopathy phenotypes and for identifying structural targets for intervention that can be tested in silico and in vitro.
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Affiliation(s)
- Salwa Abdullah
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721
| | - Melissa L Lynn
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, 85721
| | - Mark T McConnell
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, 85721
| | - Matthew M Klass
- Department of Physiological Sciences, University of Arizona, Tucson, Arizona, 85721
| | - Anthony P Baldo
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721
| | - Steven D Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721
| | - Jil C Tardiff
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721 .,Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, 85721.,Department of Physiological Sciences, University of Arizona, Tucson, Arizona, 85721.,Department of Medicine, University of Arizona, Tucson, Arizona 85721
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Antinori S, Ridolfo AL, Giacomelli A, Bonazzetti C, Corbellino M, Galli M. Chagas disease in Italy: the study's contribution of Italian researchers. Panminerva Med 2019; 61:464-472. [PMID: 31362479 DOI: 10.23736/s0031-0808.19.03723-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Chagas disease (CD) is an emerging infection in Italy as the consequence of the huge immigration from Latin American countries observed during the last ten-fifteen years. However, the interest of Italian researchers on CD dates back to the '80-90s of the last century with studies conducted in collaboration with Brazilian and Argentinian colleagues by Italian cardiologists and pathologists. Moreover, the first demonstration of the existence in the pre-Columbian America of Chagas disease in a Peruvian mummy was made by a group of Italian paleopathologists. Seroprevalence studies performed between 2010-2014 in Negrar (Verona), Bergamo, Milan, Florence and Rome shows Trypanosoma cruzi infection ranging from 3.9% to 17.1% with people coming from Bolivia as the most affected. As observed in Latin America about 30% of screened subjects in Italy are affected by cardiac or digestive forms of CD. More than 20% of subjects treated with benznidazole discontinued it permanently due to adverse events.
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Affiliation(s)
- Spinello Antinori
- Luigi Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy - .,III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy -
| | - Anna L Ridolfo
- III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Andrea Giacomelli
- III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Cecilia Bonazzetti
- Luigi Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.,III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Mario Corbellino
- III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
| | - Massimo Galli
- Luigi Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.,III Division of Infectious Diseases, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Milan, Italy
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Wang L, Kryshtal DO, Kim K, Parikh S, Cadar AG, Bersell KR, He H, Pinto JR, Knollmann BC. Myofilament Calcium-Buffering Dependent Action Potential Triangulation in Human-Induced Pluripotent Stem Cell Model of Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2019; 70:2600-2602. [PMID: 29145956 DOI: 10.1016/j.jacc.2017.09.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/12/2017] [Accepted: 09/12/2017] [Indexed: 11/25/2022]
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Abstract
Postmortem imaging is increasingly used in forensic practice as good complementary tool to conventional autopsy investigations. Over the last decade, postmortem cardiac magnetic resonance (PMCMR) imaging was introduced in forensic investigations of natural deaths related to cardiovascular diseases, which represent the most common causes of death in developed countries. Postmortem CMR application has yielded interesting results in ischemic myocardium injury investigations and in visualizing other pathological findings in the heart. This review presents the actual state of postmortem imaging for cardiovascular pathologies in cases of sudden cardiac death (SCD), taking into consideration both the advantages and limitations of PMCMR application.
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40
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Zhou W, Bos JM, Ye D, Tester DJ, Hrstka S, Maleszewski JJ, Ommen SR, Nishimura RA, Schaff HV, Kim CS, Ackerman MJ. Induced Pluripotent Stem Cell–Derived Cardiomyocytes from a Patient with MYL2-R58Q-Mediated Apical Hypertrophic Cardiomyopathy Show Hypertrophy, Myofibrillar Disarray, and Calcium Perturbations. J Cardiovasc Transl Res 2019; 12:394-403. [DOI: 10.1007/s12265-019-09873-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 02/13/2019] [Indexed: 12/31/2022]
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Shah AB, Bechis MZ, Brown M, Finch JM, Loomer G, Groezinger E, Weiner RB, Wasfy MM, Picard MH, Fifer MA, Lewis GB, Baggish AL. Catecholamine response to exercise in patients with non-obstructive hypertrophic cardiomyopathy. J Physiol 2019; 597:1337-1346. [PMID: 30552684 DOI: 10.1113/jp277494] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 12/05/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). As a result, the majority of patients with HCM deliberately reduce their habitual physical activity after diagnosis and this lifestyle change puts them at risk for sequelae of a sedentary lifestyle: weight gain, hypertension, hyperlipidaemia, insulin resistance, coronary artery disease, and increased morbidity and mortality. We show that plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold, a parameter that can be defined during cardiopulmonary exercise testing, but rise rapidly at higher intensities of exercise. These findings suggest that cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM. ABSTRACT Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). However, the impact of exercise intensity on plasma catecholamine levels among HCM patients has not been rigorously defined. We conducted a prospective observational case-control study of men with non-obstructive HCM and age-matched controls. Laboratory-based cardiopulmonary exercise testing coupled with serial phlebotomy was used to define the relationship between exercise intensity and plasma catecholamine levels. Compared to controls (C, n = 5), HCM participants (H, n = 9) demonstrated higher left ventricular mass index (115 ± 20 vs. 90 ± 16 g/m2 , P = 0.03) and maximal left ventricular wall thickness (16 ± 1 vs. 8 ± 1 mm, P < 0.001) but similar body mass index, resting heart rate, peak oxygen consumption (H = 40 ± 13 vs. C = 42 ± 7 ml/kg/min, P = 0.81) and heart rate at the ventilatory threshold (H = 78 ± 6 vs. C = 78 ± 4% peak heart rate, P = 0.92). During incremental effort exercise in both groups, concentrations of adrenaline and noradrenaline were unchanged through low- and moderate-exercise intensity until reaching a catecholamine threshold (H = 82 ± 4 vs. C = 85 ± 3% peak heart rate, P = 0.86) after which levels of both molecules rose rapidly. In patients with mild non-obstructive HCM, plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold but rise rapidly at higher intensities of exercise. Routine cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM.
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Affiliation(s)
- Ankit B Shah
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Mary Z Bechis
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Marcel Brown
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Jennifer Michaud Finch
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Garrett Loomer
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Erich Groezinger
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Rory B Weiner
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Meagan M Wasfy
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Michael H Picard
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Michael A Fifer
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Gregory B Lewis
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
| | - Aaron L Baggish
- Division of Cardiology, Massachusetts General Hospital, 55 Fruit Street, Yawkey Suite 5B, Boston, MA, USA
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Dieseldorff Jones KM, Koh Y, Weller RS, Turna RS, Ahmad F, Huke S, Knollmann BC, Pinto JR, Hwang HS. Pathogenic troponin T mutants with opposing effects on myofilament Ca 2+ sensitivity attenuate cardiomyopathy phenotypes in mice. Arch Biochem Biophys 2018; 661:125-131. [PMID: 30445044 DOI: 10.1016/j.abb.2018.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 08/28/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023]
Abstract
Mutations in cardiac troponin T (TnT) associated with hypertrophic cardiomyopathy generally lead to an increase in the Ca2+ sensitivity of contraction and susceptibility to arrhythmias. In contrast, TnT mutations linked to dilated cardiomyopathy decrease the Ca2+ sensitivity of contraction. Here we tested the hypothesis that two TnT disease mutations with opposite effects on myofilament Ca2+ sensitivity can attenuate each other's phenotype. We crossed transgenic mice expressing the HCM TnT-I79N mutation (I79N) with a DCM knock-in mouse model carrying the heterozygous TnT-R141W mutation (HET). The results of the Ca2+ sensitivity in skinned cardiac muscle preparations ranked from highest to lowest were as follow: I79N > I79N/HET > NTg > HET. Echocardiographic measurements revealed an improvement in hemodynamic parameters in I79N/HET compared to I79N and normalization of left ventricular dimensions and volumes compared to both I79N and HET. Ex vivo testing showed that the I79N/HET mouse hearts had reduced arrhythmia susceptibility compared to I79N mice. These results suggest that two disease mutations in TnT that have opposite effects on the myofilament Ca2+ sensitivity can paradoxically ameliorate each other's disease phenotype. Normalizing myofilament Ca2+ sensitivity may be a promising new treatment approach for a variety of diseases.
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Affiliation(s)
| | - Yeojung Koh
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Rebecca S Weller
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Rajdeep S Turna
- Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Ferhaan Ahmad
- Department of Internal Medicine University of Iowa, Iowa City, IA, USA
| | - Sabine Huke
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA; Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Björn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA
| | | | - Hyun Seok Hwang
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.
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Zebrafish heart failure models: opportunities and challenges. Amino Acids 2018; 50:787-798. [DOI: 10.1007/s00726-018-2578-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 04/24/2018] [Indexed: 01/03/2023]
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44
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Vakrou S, Fukunaga R, Foster DB, Sorensen L, Liu Y, Guan Y, Woldemichael K, Pineda-Reyes R, Liu T, Tardiff JC, Leinwand LA, Tocchetti CG, Abraham TP, O'Rourke B, Aon MA, Abraham MR. Allele-specific differences in transcriptome, miRNome, and mitochondrial function in two hypertrophic cardiomyopathy mouse models. JCI Insight 2018; 3:94493. [PMID: 29563334 DOI: 10.1172/jci.insight.94493] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 02/14/2018] [Indexed: 01/06/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) stems from mutations in sarcomeric proteins that elicit distinct biophysical sequelae, which in turn may yield radically different intracellular signaling and molecular pathologic profiles. These signaling events remain largely unaddressed by clinical trials that have selected patients based on clinical HCM diagnosis, irrespective of genotype. In this study, we determined how two mouse models of HCM differ, with respect to cellular/mitochondrial function and molecular biosignatures, at an early stage of disease. We show that hearts from young R92W-TnT and R403Q-αMyHC mutation-bearing mice differ in their transcriptome, miRNome, intracellular redox environment, mitochondrial antioxidant defense mechanisms, and susceptibility to mitochondrial permeability transition pore opening. Pathway analysis of mRNA-sequencing data and microRNA profiles indicate that R92W-TnT mutants exhibit a biosignature consistent with activation of profibrotic TGF-β signaling. Our results suggest that the oxidative environment and mitochondrial impairment in young R92W-TnT mice promote activation of TGF-β signaling that foreshadows a pernicious phenotype in young individuals. Of the two mutations, R92W-TnT is more likely to benefit from anti-TGF-β signaling effects conferred by angiotensin receptor blockers and may be responsive to mitochondrial antioxidant strategies in the early stage of disease. Molecular and functional profiling may therefore serve as aids to guide precision therapy for HCM.
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Affiliation(s)
- Styliani Vakrou
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA.,Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Ryuya Fukunaga
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - D Brian Foster
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Lars Sorensen
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA.,Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Yamin Liu
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA.,Division of Cardiology, UCSF, San Francisco, California, USA
| | - Yufan Guan
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA
| | - Kirubel Woldemichael
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA
| | - Roberto Pineda-Reyes
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ting Liu
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jill C Tardiff
- Department of Internal Medicine and Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Leslie A Leinwand
- Department of Molecular, Cellular, and Developmental Biology and the BioFrontiers Institute, University of Colorado, Boulder, Colorado, USA
| | - Carlo G Tocchetti
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Theodore P Abraham
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA.,Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Division of Cardiology, UCSF, San Francisco, California, USA
| | - Brian O'Rourke
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Miguel A Aon
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - M Roselle Abraham
- Hypertrophic Cardiomyopathy Center of Excellence, Johns Hopkins University, Baltimore, Maryland, USA.,Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Division of Cardiology, UCSF, San Francisco, California, USA
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Borisov KV. Surgery of Hypertrophic Obstructive Cardiomyopathy in Patients With Severe Hypertrophy, Myocardial Fibrosis, and Ventricular Tachycardia. Ann Thorac Surg 2018. [PMID: 29534954 DOI: 10.1016/j.athoracsur.2018.02.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND In patients with hypertrophic obstructive cardiomyopathy (HOCM) myocardial fibrosis is an independent predictor of adverse outcome. A new technique of HOCM surgical correction in patients with severe hypertrophy and septal myocardial fibrosis has been proposed. METHODS The excision of the asymmetrical hypertrophied area of the interventricular septum causing obstruction was performed from the conal part of the right ventricle corresponding to the zone of obstruction of the left ventricle (LV). The areas of septal myocardial fibrosis were removed corresponding to the zone of delayed enhancement imaging. Myocardial fibrosis was detected by cardiovascular magnetic resonance. Eleven patients with HOCM with severe hypertrophy, myocardial fibrosis, and episodes of ventricular tachycardia underwent this procedure. Five patients had biventricular obstruction. The follow-up period was 39 ± 9 months. RESULTS Ten patients were free of symptoms (New York Heart Association class I) and 1 patient had only mild limitations. The mean echocardiographic gradient in the LV decreased from 88.9 ± 10.0 to 9.7 ± 2.1 mm Hg, the mean value of gradient in the right ventricular outflow tract was reduced from 45.2 ± 4.7 to 3.8 ± 1.3 mm Hg. Echocardiographically determined septal thickness was reduced from 34.5 ± 3.8 to 15.5 ± 1.6 mm. Sinus rhythm without block of His bundle right branch was noted in all patients after the operation. Ventricular tachycardia was not registered. CONCLUSIONS The benefits of applying the technique include effective surgical treatment of patients with HOCM with severe hypertrophy and biventricular obstruction. It may be an appropriate choice for patients with HOCM with septal myocardial fibrosis.
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Lyon A, Ariga R, Mincholé A, Mahmod M, Ormondroyd E, Laguna P, de Freitas N, Neubauer S, Watkins H, Rodriguez B. Distinct ECG Phenotypes Identified in Hypertrophic Cardiomyopathy Using Machine Learning Associate With Arrhythmic Risk Markers. Front Physiol 2018; 9:213. [PMID: 29593570 PMCID: PMC5859357 DOI: 10.3389/fphys.2018.00213] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/26/2018] [Indexed: 12/24/2022] Open
Abstract
Aims: Ventricular arrhythmia triggers sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM), yet electrophysiological biomarkers are not used for risk stratification. Our aim was to identify distinct HCM phenotypes based on ECG computational analysis, and characterize differences in clinical risk factors and anatomical differences using cardiac magnetic resonance (CMR) imaging. Methods: High-fidelity 12-lead Holter ECGs from 85 HCM patients and 38 healthy volunteers were analyzed using mathematical modeling and computational clustering to identify phenotypic subgroups. Clinical features and the extent and distribution of hypertrophy assessed by CMR were evaluated in the subgroups. Results: QRS morphology alone was crucial to identify three HCM phenotypes with very distinct QRS patterns. Group 1 (n = 44) showed normal QRS morphology, Group 2 (n = 19) showed short R and deep S waves in V4, and Group 3 (n = 22) exhibited short R and long S waves in V4-6, and left QRS axis deviation. However, no differences in arrhythmic risk or distribution of hypertrophy were observed between these groups. Including T wave biomarkers in the clustering, four HCM phenotypes were identified: Group 1A (n = 20), with primary repolarization abnormalities showing normal QRS yet inverted T waves, Group 1B (n = 24), with normal QRS morphology and upright T waves, and Group 2 and Group 3 remaining as before, with upright T waves. Group 1A patients, with normal QRS and inverted T wave, showed increased HCM Risk-SCD scores (1A: 4.0%, 1B: 1.8%, 2: 2.1%, 3: 2.5%, p = 0.0001), and a predominance of coexisting septal and apical hypertrophy (p < 0.0001). HCM patients in Groups 2 and 3 exhibited predominantly septal hypertrophy (85 and 90%, respectively). Conclusion: HCM patients were classified in four subgroups with distinct ECG features. Patients with primary T wave inversion not secondary to QRS abnormalities had increased HCM Risk-SCD scores and coexisting septal and apical hypertrophy, suggesting that primary T wave inversion may increase SCD risk in HCM, rather than T wave inversion secondary to depolarization abnormalities. Computational ECG phenotyping provides insight into the underlying processes captured by the ECG and has the potential to be a novel and independent factor for risk stratification.
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Affiliation(s)
- Aurore Lyon
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Rina Ariga
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ana Mincholé
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Masliza Mahmod
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Elizabeth Ormondroyd
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Pablo Laguna
- Biomedical Signal Interpretation & Computational Simulation Group, CIBER-BBN, University of Zaragoza, Zaragoza, Spain
| | - Nando de Freitas
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
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Wang L, Kim K, Parikh S, Cadar AG, Bersell KR, He H, Pinto JR, Kryshtal DO, Knollmann BC. Hypertrophic cardiomyopathy-linked mutation in troponin T causes myofibrillar disarray and pro-arrhythmic action potential changes in human iPSC cardiomyocytes. J Mol Cell Cardiol 2018; 114:320-327. [PMID: 29217433 PMCID: PMC5800960 DOI: 10.1016/j.yjmcc.2017.12.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/01/2017] [Accepted: 12/03/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Mutations in cardiac troponin T (TnT) are linked to increased risk of ventricular arrhythmia and sudden death despite causing little to no cardiac hypertrophy. Studies in mice suggest that the hypertrophic cardiomyopathy (HCM)-associated TnT-I79N mutation increases myofilament Ca sensitivity and is arrhythmogenic, but whether findings from mice translate to human cardiomyocyte electrophysiology is not known. OBJECTIVES To study the effects of the TnT-I79N mutation in human cardiomyocytes. METHODS Using CRISPR/Cas9, the TnT-I79N mutation was introduced into human induced pluripotent stem cells (hiPSCs). We then used the matrigel mattress method to generate single rod-shaped cardiomyocytes (CMs) and studied contractility, Ca handling and electrophysiology. RESULTS Compared to isogenic control hiPSC-CMs, TnT-I79N hiPSC-CMs exhibited sarcomere disorganization, increased systolic function and impaired relaxation. The Ca-dependence of contractility was leftward shifted in mutation containing cardiomyocytes, demonstrating increased myofilament Ca sensitivity. In voltage-clamped hiPSC-CMs, TnT-I79N reduced intracellular Ca transients by enhancing cytosolic Ca buffering. These changes in Ca handling resulted in beat-to-beat instability and triangulation of the cardiac action potential, which are predictors of arrhythmia risk. The myofilament Ca sensitizer EMD57033 produced similar action potential triangulation in control hiPSC-CMs. CONCLUSIONS The TnT-I79N hiPSC-CM model not only reproduces key cellular features of TnT-linked HCM such as myofilament disarray, hypercontractility and diastolic dysfunction, but also suggests that this TnT mutation causes pro-arrhythmic changes of the human ventricular action potential.
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Affiliation(s)
- Lili Wang
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Kyungsoo Kim
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Shan Parikh
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Adrian Gabriel Cadar
- Division of Cardiovascular Medicine, Vanderbilt Univ Medical Ctr, Nashville, TN, Light Hall 1155A, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Kevin R Bersell
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA
| | - Huan He
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA; Translational Science Laboratory, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, FL 32306, USA
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, FL 32306, USA
| | - Dmytro O Kryshtal
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA.
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt Univ Medical Ctr, Nashville, TN, Medical Research Building IV, Rm.1275, 2215B Garland Ave, Nashville, TN 37232, USA.
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McDiarmid AK, Pellicori P, Cleland JG, Plein S. Taxonomy of segmental myocardial systolic dysfunction. Eur Heart J 2017; 38:942-954. [PMID: 27147609 PMCID: PMC5381597 DOI: 10.1093/eurheartj/ehw140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/10/2016] [Indexed: 12/13/2022] Open
Abstract
The terms used to describe different states of myocardial health and disease are poorly defined. Imprecision and inconsistency in nomenclature can lead to difficulty in interpreting and applying trial outcomes to clinical practice. In particular, the terms ‘viable’ and ‘hibernating’ are commonly applied interchangeably and incorrectly to myocardium that exhibits chronic contractile dysfunction in patients with ischaemic heart disease. The range of inherent differences amongst imaging modalities used to define myocardial health and disease add further challenges to consistent definitions. The results of several large trials have led to renewed discussion about the classification of dysfunctional myocardial segments. This article aims to describe the diverse myocardial pathologies that may affect the myocardium in ischaemic heart disease and cardiomyopathy, and how they may be assessed with non-invasive imaging techniques in order to provide a taxonomy of myocardial dysfunction.
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Affiliation(s)
- Adam K McDiarmid
- Multidisciplinary Cardiovascular Research Centre & Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Pierpaolo Pellicori
- Academic Cardiology Unit, University of Hull, Castle Hill Hospital, Kingston upon Hull, UK
| | - John G Cleland
- Academic Cardiology Unit, University of Hull, Castle Hill Hospital, Kingston upon Hull, UK
| | - Sven Plein
- Multidisciplinary Cardiovascular Research Centre & Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
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Marian AJ, Braunwald E. Hypertrophic Cardiomyopathy: Genetics, Pathogenesis, Clinical Manifestations, Diagnosis, and Therapy. Circ Res 2017; 121:749-770. [PMID: 28912181 DOI: 10.1161/circresaha.117.311059] [Citation(s) in RCA: 751] [Impact Index Per Article: 107.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disorder that is characterized by left ventricular hypertrophy unexplained by secondary causes and a nondilated left ventricle with preserved or increased ejection fraction. It is commonly asymmetrical with the most severe hypertrophy involving the basal interventricular septum. Left ventricular outflow tract obstruction is present at rest in about one third of the patients and can be provoked in another third. The histological features of HCM include myocyte hypertrophy and disarray, as well as interstitial fibrosis. The hypertrophy is also frequently associated with left ventricular diastolic dysfunction. In the majority of patients, HCM has a relatively benign course. However, HCM is also an important cause of sudden cardiac death, particularly in adolescents and young adults. Nonsustained ventricular tachycardia, syncope, a family history of sudden cardiac death, and severe cardiac hypertrophy are major risk factors for sudden cardiac death. This complication can usually be averted by implantation of a cardioverter-defibrillator in appropriate high-risk patients. Atrial fibrillation is also a common complication and is not well tolerated. Mutations in over a dozen genes encoding sarcomere-associated proteins cause HCM. MYH7 and MYBPC3, encoding β-myosin heavy chain and myosin-binding protein C, respectively, are the 2 most common genes involved, together accounting for ≈50% of the HCM families. In ≈40% of HCM patients, the causal genes remain to be identified. Mutations in genes responsible for storage diseases also cause a phenotype resembling HCM (genocopy or phenocopy). The routine applications of genetic testing and preclinical identification of family members represents an important advance. The genetic discoveries have enhanced understanding of the molecular pathogenesis of HCM and have stimulated efforts designed to identify new therapeutic agents.
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Affiliation(s)
- Ali J Marian
- From the Center for Cardiovascular Genetics, Institute of Molecular Medicine, Department of Medicine, University of Texas Health Sciences Center at Houston (A.J.M.); Texas Heart Institute, Houston (A.J.M.); and TIMI Study Group, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (E.B.).
| | - Eugene Braunwald
- From the Center for Cardiovascular Genetics, Institute of Molecular Medicine, Department of Medicine, University of Texas Health Sciences Center at Houston (A.J.M.); Texas Heart Institute, Houston (A.J.M.); and TIMI Study Group, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (E.B.)
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50
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Abstract
Right ventricular (RV) hypertrophy is common in patients with hypertrophic cardiomyopathy (HCM), and is associated with more severe disease. Conventional surgical strategies such as the traditional Morrow procedure pose a particularly high risk to patients with severe hypertrophy and RV obstruction, for whom the most appropriate therapeutic approach has not yet been established. We have proposed a new technique for surgical correction in patients with hypertrophic obstructive cardiomyopathy and severe hypertrophy, which involves approaching the area of obstruction by entering through the conal part of the RV. This novel technique provides effective elimination of biventricular obstruction and the precise removal of the areas of septal fibrosis in patients with hypertrophic obstructive cardiomyopathy. The current literature review analyzes the indications and various techniques for performing a RV myectomy, and presents the results of follow-up assessments in patients with biventricular obstruction and severe hypertrophy.
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Affiliation(s)
- Konstantin V Borisov
- University Paris Descartes, Sorbonne Paris Cite, 75475 Paris, France.,German-Russian Cardiac Clinic, Moscow, Russia
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