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Huang Y, Yan S, Song Y, Wang X, Yang K, Zhang L, Gui W, Wang J, Yang Y, Xie Y, Wang D, Li X. Del nido versus conventional blood cardioplegia in patients with obstructive hypertrophic cardiomyopathy. Perfusion 2024; 39:1088-1097. [PMID: 36921566 DOI: 10.1177/02676591231163270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
BACKGROUND Myocardial protection is essential in cardiac surgery with cardiopulmonary bypass The Del Nido cardioplegia which was initially used in pediatric cardiac surgery, has been increasingly used in adult cardiac surgery recently. However, no literature has reported the efficacy of DNC in hypertrophic obstructive cardiomyopathy. METHODS This retrospective study involved elective patients who underwent extended surgical myectomy with or without concomitant cardiac surgical procedures between September 2017 and June 2022. Patients were distributed into two groups, the DNC and the CBC group. The primary outcome was high-sensitivity cardiac troponin I (hs-TnI) and creatine kinase-MB (CK-MB) levels at the 0, 1, and 2 postoperative days. The secondary outcomes contained: intraoperative LVEF, return to spontaneous rhythm; postoperative myocardial infarction, worsening or deteriorating of EF, mechanical circulatory support; new-onset atrial fibrillation; mechanical ventilation duration; intensive care unit hours; in-hospital days. RESULTS Fifty-nine patients were included and divided into the CBC (n = 15) and the DNC group (n = 44). There was no statistical difference in patients' demographics and preoperative parameters between the two groups. No in-hospital mortality. The total cardioplegia volume [21.93(18.36,26.07) vs. 25.68(23.17,37.12), p = 0.012] and infusion times [1(1,1) vs. 2(2,3), p = 0.000] were less and the incidence of return to spontaneous rhythm after declamping was higher in the DNC group [97.7% vs. 73.3%, p = 0.013]. Postoperative hs-TnI and CK-MB levels were comparable between the two groups. A longer DNC infusion interval was associated with higher levels of CK-MB on postoperative day 1 and day 2 (p = 0.009 and p = 0.011, respectively). CONCLUSIONS The use of DNC in extended surgical myectomy procedure was as safe and effective as CBC. However, DNC infusion interval over 60 minutes was associated with increased postoperative CK-MB levels.
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Affiliation(s)
- Yingshan Huang
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Shujie Yan
- Department of Cardiopulmonary Bypass, State key laboratory of Cardiovascular Medicine, Fuwai Hospital, National center for Cardiovascular disease, Chinese Academy of Medical science and Peking Union Medical College, Beijing, China
| | - Yi Song
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Xiaoqi Wang
- Department of Cardiac Surgery, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Ke Yang
- Department of Anesthesiology, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Ling Zhang
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Wenting Gui
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Jiao Wang
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Yunling Yang
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Yan Xie
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Dongmei Wang
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Xinyue Li
- Department of Cardiopulmonary Bypass, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
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Lim S, Mangala MM, Holliday M, Cserne Szappanos H, Barratt-Ross S, Li S, Thorpe J, Liang W, Ranpura GN, Vandenberg JI, Semsarian C, Hill AP, Hool LC. Reduced connexin-43 expression, slow conduction and repolarisation dispersion in a model of hypertrophic cardiomyopathy. Dis Model Mech 2024; 17:dmm050407. [PMID: 39189070 PMCID: PMC11381919 DOI: 10.1242/dmm.050407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 07/16/2024] [Indexed: 08/28/2024] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is an inherited heart muscle disease that is characterised by left ventricular wall thickening, cardiomyocyte disarray and fibrosis, and is associated with arrhythmias, heart failure and sudden death. However, it is unclear to what extent the electrophysiological disturbances that lead to sudden death occur secondary to structural changes in the myocardium or as a result of HCM cardiomyocyte electrophysiology. In this study, we used an induced pluripotent stem cell model of the R403Q variant in myosin heavy chain 7 (MYH7) to study the electrophysiology of HCM cardiomyocytes in electrically coupled syncytia, revealing significant conduction slowing and increased spatial dispersion of repolarisation - both well-established substrates for arrhythmia. Analysis of rhythmonome protein expression in MYH7 R403Q cardiomyocytes showed reduced expression of connexin-43 (also known as GJA1), sodium channels and inward rectifier potassium channels - a three-way hit that reduces electrotonic coupling and slows cardiac conduction. Our data represent a previously unreported, biophysical basis for arrhythmia in HCM that is intrinsic to cardiomyocyte electrophysiology. Later in the progression of the disease, these proarrhythmic phenotypes may be accentuated by myocyte disarray and fibrosis to contribute to sudden death.
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Affiliation(s)
- Seakcheng Lim
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
| | - Melissa M Mangala
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney 2052, Australia
| | - Mira Holliday
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
| | | | - Samantha Barratt-Ross
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
| | - Serena Li
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
| | - Jordan Thorpe
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney 2052, Australia
| | - Whitney Liang
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney 2052, Australia
| | - Ginell N Ranpura
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney 2052, Australia
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney 2050, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney 2050, Australia
- Department of Cardiology, Royal Prince Alfred Hospital, Sydney 2050, Australia
| | | | - Livia C Hool
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia
- School of Human Sciences, The University of Western Australia, Crawley 6009, Australia
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Canciello G, Lombardi R, Borrelli F, Ordine L, Chen SN, Santoro C, Frisso G, di Napoli S, Polizzi R, Cristiano S, Esposito G, Losi MA. Echocardiographic Strain Abnormalities Precede Left Ventricular Hypertrophy Development in Hypertrophic Cardiomyopathy Mutation Carriers. Int J Mol Sci 2024; 25:8128. [PMID: 39125703 PMCID: PMC11312232 DOI: 10.3390/ijms25158128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/17/2024] [Accepted: 07/23/2024] [Indexed: 08/12/2024] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disease characterized by unexplained left ventricular hypertrophy (LVH), diastolic dysfunction, and increased sudden-death risk. Early detection of the phenotypic expression of the disease in genetic carriers without LVH (Gen+/Phen-) is crucial for emerging therapies. This clinical study aims to identify echocardiographic predictors of phenotypic development in Gen+/Phen-. Sixteen Gen+/Phen- (one subject with troponin T, six with myosin heavy chain-7, and nine with myosin-binding protein C3 mutations), represented the study population. At first and last visit we performed comprehensive 2D speckle-tracking strain echocardiography. During a follow-up of 8 ± 5 years, five carriers developed LVH (LVH+). At baseline, these patients were older than those who did not develop LVH (LVH-) (30 ± 8 vs. 15 ± 8 years, p = 0.005). LVH+ had reduced peak global strain rate during the isovolumic relaxation period (SRIVR) (0.28 ± 0.05 vs. 0.40 ± 0.11 1/s, p = 0.048) and lower global longitudinal strain (GLS) (-19.8 ± 0.4 vs. -22.3 ± 1.1%; p < 0.0001) than LVH- at baseline. SRIVR and GLS were not correlated with age (overall, p > 0.08). This is the first HCM study investigating subjects before they manifest clinically significant or relevant disease burden or symptomatology, comparing at baseline HCM Gen+/Phen- subjects who will develop LVH with those who will not. Furthermore, we identified highly sensitive, easily obtainable, age- and load-independent echocardiographic predictors of phenotype development in HCM gene carriers who may undergo early preventive treatment.
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Affiliation(s)
- Grazia Canciello
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Raffaella Lombardi
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Felice Borrelli
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Leopoldo Ordine
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Suet-Nee Chen
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Ciro Santoro
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Giulia Frisso
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, 80131 Naples, Italy;
| | - Salvatore di Napoli
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Roberto Polizzi
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Stefano Cristiano
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
| | - Maria-Angela Losi
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Via S Pansini 5, 80131 Napoli, Italy; (G.C.); (F.B.); (L.O.); (C.S.); (S.d.N.); (R.P.); (S.C.); (G.E.); (M.-A.L.)
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Coleman JA, Doste R, Ashkir Z, Coppini R, Sachetto R, Watkins H, Raman B, Bueno-Orovio A. Mechanisms of ischaemia-induced arrhythmias in hypertrophic cardiomyopathy: a large-scale computational study. Cardiovasc Res 2024; 120:914-926. [PMID: 38646743 PMCID: PMC11218689 DOI: 10.1093/cvr/cvae086] [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: 10/19/2023] [Revised: 01/31/2024] [Accepted: 03/17/2024] [Indexed: 04/23/2024] Open
Abstract
AIMS Lethal arrhythmias in hypertrophic cardiomyopathy (HCM) are widely attributed to myocardial ischaemia and fibrosis. How these factors modulate arrhythmic risk remains largely unknown, especially as invasive mapping protocols are not routinely used in these patients. By leveraging multiscale digital twin technologies, we aim to investigate ischaemic mechanisms of increased arrhythmic risk in HCM. METHODS AND RESULTS Computational models of human HCM cardiomyocytes, tissue, and ventricles were used to simulate outcomes of Phase 1A acute myocardial ischaemia. Cellular response predictions were validated with patch-clamp studies of human HCM cardiomyocytes (n = 12 cells, N = 5 patients). Ventricular simulations were informed by typical distributions of subendocardial/transmural ischaemia as analysed in perfusion scans (N = 28 patients). S1-S2 pacing protocols were used to quantify arrhythmic risk for scenarios in which regions of septal obstructive hypertrophy were affected by (i) ischaemia, (ii) ischaemia and impaired repolarization, and (iii) ischaemia, impaired repolarization, and diffuse fibrosis. HCM cardiomyocytes exhibited enhanced action potential and abnormal effective refractory period shortening to ischaemic insults. Analysis of ∼75 000 re-entry induction cases revealed that the abnormal HCM cellular response enabled establishment of arrhythmia at milder ischaemia than otherwise possible in healthy myocardium, due to larger refractoriness gradients that promoted conduction block. Arrhythmias were more easily sustained in transmural than subendocardial ischaemia. Mechanisms of ischaemia-fibrosis interaction were strongly electrophysiology dependent. Fibrosis enabled asymmetric re-entry patterns and break-up into sustained ventricular tachycardia. CONCLUSION HCM ventricles exhibited an increased risk to non-sustained and sustained re-entry, largely dominated by an impaired cellular response and deleterious interactions with the diffuse fibrotic substrate.
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Affiliation(s)
- James A Coleman
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Ruben Doste
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Zakariye Ashkir
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Raffaele Coppini
- Department of NeuroFarBa, University of Florence, Florence, Italy
| | - Rafael Sachetto
- Department of Computer Science, Federal University of São João del-Rei, São João del-Rei, Minas Gerais, Brazil
| | - Hugh Watkins
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Betty Raman
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
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5
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Dobre MA, Ahlawat S, Schelling JR. Chronic kidney disease associated cardiomyopathy: recent advances and future perspectives. Curr Opin Nephrol Hypertens 2024; 33:203-211. [PMID: 38193308 PMCID: PMC10872957 DOI: 10.1097/mnh.0000000000000952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
PURPOSE OF REVIEW Cardiomyopathy in chronic kidney disease (CKD) is a complex condition with multiple triggers and poor prognosis. This review provides an overview of recent advances in CKD-associated cardiomyopathy, with a focus on pathophysiology, newly discovered biomarkers and potential therapeutic targets. RECENT FINDINGS CKD is associated with a specific pattern of myocardial hypertrophy and fibrosis, resulting in diastolic and systolic dysfunction, and often triggered by nonatherosclerotic processes. Novel biomarkers, including amino-terminal type III procollagen peptide (PIIINP), carboxy-terminal type I procollagen peptide (PICP), FGF23, marinobufagenin, and several miRNAs, show promise for early detection and risk stratification. Treatment options for CKD-associated cardiomyopathy are limited. Sodium glucose cotransporter-2 inhibitors have been shown to reduce left ventricle hypertrophy and improve ejection fraction in individuals with diabetes and mild CKD, and are currently under investigation for more advanced stages of CKD. In hemodialysis patients calcimimetic etelcalcetide resulted in a significant reduction in left ventricular mass. SUMMARY CKD-associated cardiomyopathy is a common and severe complication in CKD. The identification of novel biomarkers may lead to future therapeutic targets. Randomized clinical trials in individuals with more advanced CKD would be well posed to expand treatment options for this debilitating condition.
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Affiliation(s)
- Mirela A Dobre
- Division of Nephrology and Hypertension, University Hospitals Cleveland Medical Center
- School of Medicine
| | - Shruti Ahlawat
- Division of Nephrology and Hypertension, University Hospitals Cleveland Medical Center
| | - Jeffrey R Schelling
- Division of Nephrology and Hypertension, University Hospitals Cleveland Medical Center
- School of Medicine
- Department of Physiology & Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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Novo Matos J, Payne JR. Predicting Development of Hypertrophic Cardiomyopathy and Disease Outcomes in Cats. Vet Clin North Am Small Anim Pract 2023; 53:1277-1292. [PMID: 37500329 DOI: 10.1016/j.cvsm.2023.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Echocardiography is the gold standard imaging modality to diagnose hypertrophic cardiomyopathy (HCM) in cats. Echocardiographic features can predict both cats at an increased risk of developing HCM and cats with HCM at an increased risk of developing cardiovascular events or experiencing cardiac death. Left atrial dysfunction seems to be an important feature of HCM, as it is an early phenotypic abnormality and is also associated with worse outcome.
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Affiliation(s)
- Jose Novo Matos
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
| | - Jessie Rose Payne
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, Langford BS40 5DU, UK
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7
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Wang K, Schriver BJ, Aschar-Sobbi R, Yi AY, Feric NT, Graziano MP. Human engineered cardiac tissue model of hypertrophic cardiomyopathy recapitulates key hallmarks of the disease and the effect of chronic mavacamten treatment. Front Bioeng Biotechnol 2023; 11:1227184. [PMID: 37771571 PMCID: PMC10523579 DOI: 10.3389/fbioe.2023.1227184] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023] Open
Abstract
Introduction: The development of patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offers an opportunity to study genotype-phenotype correlation of hypertrophic cardiomyopathy (HCM), one of the most common inherited cardiac diseases. However, immaturity of the iPSC-CMs and the lack of a multicellular composition pose concerns over its faithfulness in disease modeling and its utility in developing mechanism-specific treatment. Methods: The Biowire platform was used to generate 3D engineered cardiac tissues (ECTs) using HCM patient-derived iPSC-CMs carrying a β-myosin mutation (MYH7-R403Q) and its isogenic control (WT), withal ECTs contained healthy human cardiac fibroblasts. ECTs were subjected to electro-mechanical maturation for 6 weeks before being used in HCM phenotype studies. Results: Both WT and R403Q ECTs exhibited mature cardiac phenotypes, including a lack of automaticity and a ventricular-like action potential (AP) with a resting membrane potential < -75 mV. Compared to WT, R403Q ECTs demonstrated many HCM-associated pathological changes including increased tissue size and cell volume, shortened sarcomere length and disorganized sarcomere structure. In functional assays, R403Q ECTs showed increased twitch amplitude, slower contractile kinetics, a less pronounced force-frequency relationship, a smaller post-rest potentiation, prolonged AP durations, and slower Ca2+ transient decay time. Finally, we observed downregulation of calcium handling genes and upregulation of NPPB in R403Q vs. WT ECTs. In an HCM phenotype prevention experiment, ECTs were treated for 5-weeks with 250 nM mavacamten or a vehicle control. We found that chronic mavacamten treatment of R403Q ECTs: (i) shortened relaxation time, (ii) reduced APD90 prolongation, (iii) upregulated ADRB2, ATP2A2, RYR2, and CACNA1C, (iv) decreased B-type natriuretic peptide (BNP) mRNA and protein expression levels, and (v) increased sarcomere length and reduced sarcomere disarray. Discussion: Taken together, we demonstrated R403Q ECTs generated in the Biowire platform recapitulated many cardiac hypertrophy phenotypes and that chronic mavacamten treatment prevented much of the pathology. This demonstrates that the Biowire ECTs are well-suited to phenotypic-based drug discovery in a human-relevant disease model.
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Affiliation(s)
- Kai Wang
- Valo Health, Inc., Department of Discovery Research, New York, NY, United States
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8
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Valtonen J, Prajapati C, Cherian RM, Vanninen S, Ojala M, Leivo K, Heliö T, Koskenvuo J, Aalto-Setälä K. The Junctophilin-2 Mutation p.(Thr161Lys) Is Associated with Hypertrophic Cardiomyopathy Using Patient-Specific iPS Cardiomyocytes and Demonstrates Prolonged Action Potential and Increased Arrhythmogenicity. Biomedicines 2023; 11:1558. [PMID: 37371654 DOI: 10.3390/biomedicines11061558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases; it is primarily caused by mutations in sarcomeric genes. However, HCM is also associated with mutations in non-sarcomeric proteins and a Finnish founder mutation for HCM in non-sarcomeric protein junctophilin-2 (JPH2) has been identified. This study aimed at assessing the issue of modelling the rare Finnish founder mutation in cardiomyocytes (CMs) differentiated from iPSCs; therefore, presenting the same cardiac abnormalities observed in the patients. To explore the abnormal functions in JPH2-HCM, skin fibroblasts from a Finnish patient with JPH2 p.(Thr161Lys) were reprogrammed into iPSCs and further differentiated into CMs. As a control line, an isogenic counterpart was generated using the CRISPR/Cas9 genome editing method. Finally, iPSC-CMs were evaluated for the morphological and functional characteristics associated with JPH2 mutation. JPH2-hiPSC-CMs displayed key HCM hallmarks (cellular hypertrophy, multi-nucleation, sarcomeric disarray). Moreover, JPH2-hiPSC-CMs exhibit a higher degree of arrhythmia and longer action potential duration associated with slower inactivation of calcium channels. Functional evaluation supported clinical observations, with differences in beating characteristics when compared with isogenic-hiPSC-CMs. Thus, the iPSC-derived, disease-specific cardiomyocytes could serve as a translationally relevant platform to study genetic cardiac diseases.
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Affiliation(s)
- Joona Valtonen
- Heart Group, Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
| | - Chandra Prajapati
- Heart Group, Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
| | - Reeja Maria Cherian
- Heart Group, Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
| | - Sari Vanninen
- Tampere University Heart Hospital, 33520 Tampere, Finland
| | - Marisa Ojala
- Heart Group, Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
| | - Krista Leivo
- Heart and Lung Center, Helsinki University Hospital, University of Helsinki, 00290 Helsinki, Finland
| | - Tiina Heliö
- Heart and Lung Center, Helsinki University Hospital, University of Helsinki, 00290 Helsinki, Finland
| | | | - Katriina Aalto-Setälä
- Heart Group, Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
- Tampere University Heart Hospital, 33520 Tampere, Finland
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9
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Katyal A, Li COY, Franciosi S, Sanatani S. The safety of sports in children with inherited arrhythmia substrates. Front Pediatr 2023; 11:1151286. [PMID: 37124180 PMCID: PMC10132466 DOI: 10.3389/fped.2023.1151286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/22/2023] [Indexed: 05/02/2023] Open
Abstract
Sudden cardiac death (SCD) is a rare and devastating event in children and remains a leading cause of death in young athletes. Channelopathies and cardiomyopathies, in particular long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic cardiomyopathy (ACM) are associated with exercise-related SCD. Implantable cardioverter-defibrillators (ICDs) are often placed for secondary prevention for athletes with cardiomyopathy or channelopathy. There remains concern regarding the safety of return to participation with an ICD in place. Guidelines have historically recommended that patients with inherited heart rhythm disorders be restricted from competitive sports participation. Increasing evidence suggests a lower risk of exercise-related cardiac events in young athletes with inherited heart rhythm disorders. In this review, we highlight current knowledge, evolving guidelines, and present a multidisciplinary approach involving shared decision-making and appropriate planning for safe sports participation of children with inherited heart rhythm disorders.
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Affiliation(s)
| | | | | | - Shubhayan Sanatani
- British Columbia Children’s Hospital Heart Center, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
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10
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Shintani Y, Nakayama T, Masaki A, Yokoi M, Wakami K, Ito T, Goto T, Sugiura T, Inagaki H, Seo Y. Clinical impact of the pathological quantification of myocardial fibrosis and infiltrating T lymphocytes using an endomyocardial biopsy in patients with hypertrophic cardiomyopathy. Int J Cardiol 2022; 362:110-117. [PMID: 35662562 DOI: 10.1016/j.ijcard.2022.05.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/24/2022] [Accepted: 05/29/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND The impact of quantitative pathological findings derived from endomyocardial biopsies (EMB) on clinical prognosis in patients with hypertrophic cardiomyopathy (HCM) remains unclear. METHODS We retrospectively studied 55 consecutive HCM patients who underwent EMB. We quantified the collagen area fraction (CAF), the cardiomyocyte diameter, the nuclear area and circularity, and the number of myocardial infiltrating CD3+ cells using EMB samples by image analyzing software. The primary clinical endpoint was defined as a composite including cardiovascular death, admission due to heart failure and ventricular arrhythmia. RESULTS During the median follow-up of 37.2 months, the primary endpoint was found in 12 patients. No significant difference in the risk score of 5-year sudden cardiac death was observed between the event-occurrence group and the event-free group. In the multivariable Cox proportional-hazard analysis, CAF [hazard ratio (HR) per 10% increase: 1.555, 95% CI: 1.014-2.367, p = 0.044] and the number of infiltrating CD3+ cells (HR per 10% increase: 1.231, 95% CI: 1.011-1.453, p = 0.041) were the independent predictors of the primary endpoint, while the myocardial diameter and the nuclear irregularity had no significant prognostic impact. Kaplan-Meier survival curves demonstrated that patients with both higher CAF and higher number of CD3+ cells had the worst prognosis (log-rank, P < 0.001). CONCLUSIONS The higher CAF and the higher number of infiltrating CD3+ cells quantified using EMB samples were the independent predictors of poor clinical outcomes in patients with HCM. Cardiomyocyte diameter and nuclear irregularity did not significantly impact the clinical prognosis.
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Affiliation(s)
- Yasuhiro Shintani
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Takafumi Nakayama
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan.
| | - Ayako Masaki
- Department of Pathology and Molecular Diagnostics, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Masashi Yokoi
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Kazuaki Wakami
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Tsuyoshi Ito
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Toshihiko Goto
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Tomonori Sugiura
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Hiroshi Inagaki
- Department of Pathology and Molecular Diagnostics, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
| | - Yoshihiro Seo
- Department of Cardiology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan
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11
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Ma W, Gong H, Jani V, Lee KH, Landim-Vieira M, Papadaki M, Pinto JR, Aslam MI, Cammarato A, Irving T. Myofibril orientation as a metric for characterizing heart disease. Biophys J 2022; 121:565-574. [PMID: 35032456 PMCID: PMC8874025 DOI: 10.1016/j.bpj.2022.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/28/2021] [Accepted: 01/11/2022] [Indexed: 11/17/2022] Open
Abstract
Myocyte disarray is a hallmark of many cardiac disorders. However, the relationship between alterations in the orientation of individual myofibrils and myofilaments to disease progression has been largely underexplored. This oversight has predominantly been because of a paucity of methods for objective and quantitative analysis. Here, we introduce a novel, less-biased approach to quantify myofibrillar and myofilament orientation in cardiac muscle under near-physiological conditions and demonstrate its superiority as compared with conventional histological assessments. Using small-angle x-ray diffraction, we first investigated changes in myofibrillar orientation at increasing sarcomere lengths in permeabilized, relaxed, wild-type mouse myocardium from the left ventricle by assessing the angular spread of the 1,0 equatorial reflection (angle σ). At a sarcomere length of 1.9 μm, the angle σ was 0.23 ± 0.01 rad, decreased to 0.19 ± 0.01 rad at a sarcomere length of 2.1 μm, and further decreased to 0.15 ± 0.01 rad at a sarcomere length of 2.3 μm (p < 0.0001). Angle σ was significantly larger in R403Q, a MYH7 hypertrophic cardiomyopathy model, porcine myocardium (0.24 ± 0.01 rad) compared with wild-type myocardium (0.14 ± 0.005 rad; p < 0.0001), as well as in human heart failure tissue (0.19 ± 0.006 rad) when compared with nonfailing samples (0.17 ± 0.007 rad; p = 0.01). These data indicate that diseased myocardium suffers from greater myofibrillar disorientation compared with healthy controls. Finally, we showed that conventional, histology-based analysis of disarray can be subject to user bias and/or sampling error and lead to false positives. Our method for directly assessing myofibrillar orientation avoids the artifacts introduced by conventional histological approaches that assess myocyte orientation and only indirectly evaluate myofibrillar orientation, and provides a precise and objective metric for phenotypically characterizing myocardium. The ability to obtain excellent x-ray diffraction patterns from frozen human myocardium provides a new tool for investigating structural anomalies associated with cardiac diseases.
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Affiliation(s)
- Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois.
| | - Henry Gong
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois
| | - Vivek Jani
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, The Johns Hopkins University, Baltimore, Maryland; Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Maicon Landim-Vieira
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - Maria Papadaki
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, Illinois
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida
| | - M Imran Aslam
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anthony Cammarato
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Thomas Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, Illinois
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12
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Palyam V, Azam AT, Odeyinka O, Alhashimi R, Thoota S, Ashok T, Sange I. Hypertrophic Cardiomyopathy and Atrial Fibrillation: A Review. Cureus 2022; 14:e21101. [PMID: 35165560 PMCID: PMC8830388 DOI: 10.7759/cureus.21101] [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] [Accepted: 01/11/2022] [Indexed: 11/17/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is an inherited cardiological condition that exhibits various clinical symptoms. The leading cause of atrial fibrillation (AF) in patients with HCM is advanced diastolic dysfunction and left atrial dilatation and remodeling. In addition to the gradual symptomatic and functional decline caused by AF, there is an increased risk of thromboembolic disease and mortality, especially if there is a rapid ventricular rate or obstruction of the left ventricular outflow tract. The mainstay of management of AF in HCM is a combination of non-pharmacological lifestyle and risk factor modification, long-term anticoagulation, and rhythm control with anti-arrhythmic medications, septal ablation, and radiofrequency catheter ablation. This article has examined the development of AF in HCM, its clinical symptomatology, and its impact, highlighting its management and the mortality associated with AF in HCM.
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13
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Abstract
Sudden cardiac death (SCD) is the most common cause of death in childhood hypertrophic cardiomyopathy (HCM) and occurs more frequently than in adult patients. Risk stratification strategies have traditionally been extrapolated from adult practice, but newer evidence has highlighted important differences between childhood and adult cohorts, with the implication that pediatric-specific risk stratification strategies are required. Current guidelines use cumulative risk factor thresholds to recommend implantable cardioverter defibrillator (ICD) implantation but have been shown to have limited discriminatory ability. Newer pediatric models that allow clinicians to calculate individualized estimates of 5-year risk allowing, for the first time, personalization of ICD implantation decision-making have been developed. This article describes the pathophysiology, risk factors, and approach to risk stratification for SCD in childhood HCM and highlights unanswered questions.
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Affiliation(s)
- Gabrielle Norrish
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, UK; Institute of Cardiovascular Sciences University College London, UK
| | - Juan Pablo Kaski
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, UK; Institute of Cardiovascular Sciences University College London, UK.
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14
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Prevention of sudden cardiac death in childhood-onset hypertrophic cardiomyopathy. PROGRESS IN PEDIATRIC CARDIOLOGY 2021. [DOI: 10.1016/j.ppedcard.2021.101412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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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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16
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Rowin EJ, Fifer MA. Evaluating Histopathology to Improve Our Understanding of Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2021; 77:2171-2173. [PMID: 33926652 DOI: 10.1016/j.jacc.2021.03.292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 01/15/2023]
Affiliation(s)
- Ethan J Rowin
- Hypertrophic Cardiomyopathy Center, Division of Cardiology, CardioVascular Center, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Michael A Fifer
- Hypertrophic Cardiomyopathy Program, Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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17
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Prognostic value of myocardial extracellular volume fraction evaluation based on cardiac magnetic resonance T1 mapping with T1 long and short in hypertrophic cardiomyopathy. Eur Radiol 2021; 31:4557-4567. [PMID: 33449190 DOI: 10.1007/s00330-020-07650-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 10/14/2020] [Accepted: 12/18/2020] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To investigate the prognostic significance of T1 mapping using T1 long and short in hypertrophic cardiomyopathy (HCM) patients. METHODS A total of 263 consecutive patients with HCM referred for cardiovascular magnetic resonance (CMR) imaging were enrolled in this study. The imaging protocol consisted of cine, late gadolinium enhancement (LGE), and T1 mapping with T1 long and short. All patients were followed up prospectively. Outcome events were divided into the primary and secondary endpoint events. Primary endpoint events included cardiac death, heart transplant, aborted sudden death, and cardiopulmonary resuscitation after syncope. The secondary endpoint event was defined as unplanned rehospitalization for heart failure. RESULT The average follow-up duration was 28.3 ± 12.1 (range: 1-78) months. In all, 17 patients (7.0%) experienced a primary endpoint including 13 cardiovascular deaths, three aborted sudden deaths, and one resuscitation after syncope, and 34 patients experienced a secondary endpoint. Patients with primary endpoints showed a trend towards more extensive LGE (p < 0.001), significantly higher ECV (p < 0.001), and native T1 (p = 0.028) than those without events. In multivariate Cox regression analysis, ECV was independently associated with primary and secondary endpoints (p < 0.001 and p = 0.047, respectively). For every 3% increase, ECV portended a 1.374-fold increase risk of a primary endpoint occurring (p < 0.001). In the Kaplan-Meier survival analysis, the incidence of primary and secondary endpoint events was significantly higher in HCM with increased ECV (p < 0.001 and p = 0.009, respectively). CONCLUSION In patients with HCM, ECV is a strong imaging marker for predicting adverse outcome. KEY POINTS • ECV is a potent imaging index which has a strong correlation with LVEF and LVEDVI and can evaluate myocardial tissue structure and function. • ECV and LGE can provide a prognostic value in patients with hypertrophic cardiomyopathy. • ECV has stronger predictive effectiveness than LGE; even in the subgroup with LGE, ECV shows independent predictive significance for adverse events.
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18
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Wabich E, Dorniak K, Zienciuk-Krajka A, Nowak R, Raczak G, Daniłowicz-Szymanowicz L. Segmental longitudinal strain as the most accurate predictor of the patchy pattern late gadolinium enhancement in hypertrophic cardiomyopathy. J Cardiol 2020; 77:475-481. [PMID: 33246844 DOI: 10.1016/j.jjcc.2020.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/28/2020] [Accepted: 10/15/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND The prognostic value of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) has been well-established. Although cardiac magnetic resonance (CMR) is the method of choice in its revealing as the presence of late gadolinium enhancement (LGE), this technique still has limited availability in daily clinical practice. Two-dimensional speckle tracking echocardiography (2D STE) seems to be helpful in verification which HCM patient has the highest probability of LGE presence and hence needs to be qualified to CMR. While the majority of HCM patients have a patchy pattern of myocardial fibrosis, the aim of this study was to evaluate whether segmental rather than global longitudinal strain is more accurate in the identification of the presence of LGE. METHODS Forty-six HCM patients had transthoracic echocardiography and CMR imaging performed. Each patient had global longitudinal strain and rotation parameters calculated, as well as segmental analyses for wall thickness, longitudinal strain, and LGE presence based on 736 segments of the left ventricle (LV). The presence of LGE in CMR was confirmed on a per-segment basis, which was similar to LV segments in the echocardiographic examination. All patients were divided into two groups according to the CMR result: LGE (+) and LGE (-). RESULTS Receiver-operating characteristic analyses identified peak global longitudinal strain and peak twisting velocity with the cut-off values -14.4% and 116°/s respectively as the accurate predictors of LGE presence in CMR, whereas segmental longitudinal strain of -12.5% cut-off value had the highest area under the curve value (87.4%, confidence interval 84.5-90.3%), with 93.7% sensitivity, 86.5% negative predictive value, and 55% specificity. CONCLUSIONS Segmental longitudinal strain with the cut-off value of -12.5% has the highest discriminatory power for LGE presence and seems to be more adequate than global speckle tracking parameters in identification of HCM patients with strong indications for CMR for more accurate risk stratification.
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Affiliation(s)
- Elżbieta Wabich
- Department of Cardiology and Electrotherapy, Medical University of Gdansk, Dębinki 7 St., 80-211 Gdansk, Poland
| | - Karolina Dorniak
- Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland
| | - Agnieszka Zienciuk-Krajka
- Department of Cardiology and Electrotherapy, Medical University of Gdansk, Dębinki 7 St., 80-211 Gdansk, Poland
| | - Radosław Nowak
- Department of Cardiology and Electrotherapy, Medical University of Gdansk, Dębinki 7 St., 80-211 Gdansk, Poland
| | - Grzegorz Raczak
- Department of Cardiology and Electrotherapy, Medical University of Gdansk, Dębinki 7 St., 80-211 Gdansk, Poland
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19
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Novo Matos J, Garcia-Canadilla P, Simcock IC, Hutchinson JC, Dobromylskyj M, Guy A, Arthurs OJ, Cook AC, Luis Fuentes V. Micro-computed tomography (micro-CT) for the assessment of myocardial disarray, fibrosis and ventricular mass in a feline model of hypertrophic cardiomyopathy. Sci Rep 2020; 10:20169. [PMID: 33214588 PMCID: PMC7678873 DOI: 10.1038/s41598-020-76809-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/02/2020] [Indexed: 01/15/2023] Open
Abstract
Micro-computed tomography (micro-CT) is a high-resolution imaging modality that provides accurate tissue characterization. Hypertrophic cardiomyopathy (HCM) occurs as a spontaneous disease in cats, and is characterized by myocardial hypertrophy, disarray and fibrosis, as in humans. While hypertrophy/mass (LVM) can be objectively measured, fibrosis and myocyte disarray are difficult to assess. We evaluated the accuracy of micro-CT for detection and quantification of myocardial disarray and fibrosis by direct comparison with histopathology. 29 cat hearts (12 normal and 17 HCM hearts) underwent micro-CT and pathologic examination. Myocyte orientation was assessed using structure tensor analysis by determination of helical angle (HA), fractional anisotropy (FA) and myocardial disarray index (MDI). Fibrosis was segmented and quantified based on comparison of gray-scale values in normal and fibrotic myocardium. LVM was obtained by determining myocardial volume. Myocardial segments with low FA, low MDI and disruption of normal HA transmural profile on micro-CT were associated with myocardial disarray on histopathology. FA was consistently lower in HCM than normal hearts. Assessment of fibrosis on micro-CT closely matched the histopathologic evaluation. LVM determined by micro-CT was higher in HCM than normal hearts. Micro-CT can be used to detect and quantify myocardial disarray and fibrosis and determine myocardial mass in HCM.
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Affiliation(s)
- Jose Novo Matos
- Clinical Sciences and Services, Royal Veterinary College, London, UK.
| | - Patricia Garcia-Canadilla
- Institut D'Investigacions Biomèdiques August Pi I Sunyer, Barcelona, Spain.,Institute of Cardiovascular Science, University College London, London, UK
| | - Ian C Simcock
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - J Ciaran Hutchinson
- Department of Histopathology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | | | - Anna Guy
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Owen J Arthurs
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Andrew C Cook
- Institute of Cardiovascular Science, University College London, London, UK
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20
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Novo Matos J, Garcia-Canadilla P, Simcock IC, Hutchinson JC, Dobromylskyj M, Guy A, Arthurs OJ, Cook AC, Luis Fuentes V. Micro-computed tomography (micro-CT) for the assessment of myocardial disarray, fibrosis and ventricular mass in a feline model of hypertrophic cardiomyopathy. Sci Rep 2020. [PMID: 33214588 DOI: 10.1038/s41598-020-76809-5.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Micro-computed tomography (micro-CT) is a high-resolution imaging modality that provides accurate tissue characterization. Hypertrophic cardiomyopathy (HCM) occurs as a spontaneous disease in cats, and is characterized by myocardial hypertrophy, disarray and fibrosis, as in humans. While hypertrophy/mass (LVM) can be objectively measured, fibrosis and myocyte disarray are difficult to assess. We evaluated the accuracy of micro-CT for detection and quantification of myocardial disarray and fibrosis by direct comparison with histopathology. 29 cat hearts (12 normal and 17 HCM hearts) underwent micro-CT and pathologic examination. Myocyte orientation was assessed using structure tensor analysis by determination of helical angle (HA), fractional anisotropy (FA) and myocardial disarray index (MDI). Fibrosis was segmented and quantified based on comparison of gray-scale values in normal and fibrotic myocardium. LVM was obtained by determining myocardial volume. Myocardial segments with low FA, low MDI and disruption of normal HA transmural profile on micro-CT were associated with myocardial disarray on histopathology. FA was consistently lower in HCM than normal hearts. Assessment of fibrosis on micro-CT closely matched the histopathologic evaluation. LVM determined by micro-CT was higher in HCM than normal hearts. Micro-CT can be used to detect and quantify myocardial disarray and fibrosis and determine myocardial mass in HCM.
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Affiliation(s)
- Jose Novo Matos
- Clinical Sciences and Services, Royal Veterinary College, London, UK.
| | - Patricia Garcia-Canadilla
- Institut D'Investigacions Biomèdiques August Pi I Sunyer, Barcelona, Spain.,Institute of Cardiovascular Science, University College London, London, UK
| | - Ian C Simcock
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - J Ciaran Hutchinson
- Department of Histopathology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | | | - Anna Guy
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Owen J Arthurs
- Department of Radiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Andrew C Cook
- Institute of Cardiovascular Science, University College London, London, UK
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21
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Manivannan SN, Darouich S, Masmoudi A, Gordon D, Zender G, Han Z, Fitzgerald-Butt S, White P, McBride KL, Kharrat M, Garg V. Novel frameshift variant in MYL2 reveals molecular differences between dominant and recessive forms of hypertrophic cardiomyopathy. PLoS Genet 2020; 16:e1008639. [PMID: 32453731 PMCID: PMC7274480 DOI: 10.1371/journal.pgen.1008639] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 06/05/2020] [Accepted: 01/29/2020] [Indexed: 12/18/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is characterized by thickening of the ventricular muscle without dilation and is often associated with dominant pathogenic variants in cardiac sarcomeric protein genes. Here, we report a family with two infants diagnosed with infantile-onset HCM and mitral valve dysplasia that led to death before one year of age. Using exome sequencing, we discovered that one of the affected children had a homozygous frameshift variant in Myosin light chain 2 (MYL2:NM_000432.3:c.431_432delCT: p.Pro144Argfs*57;MYL2-fs), which alters the last 20 amino acids of the protein and is predicted to impact the most C-terminal of the three EF-hand domains in MYL2. The parents are unaffected heterozygous carriers of the variant and the variant is absent in control cohorts from gnomAD. The absence of the phenotype in carriers and the infantile presentation of severe HCM is in contrast to HCM associated with dominant MYL2 variants. Immunohistochemical analysis of the ventricular muscle of the deceased patient with the MYL2-fs variant showed a marked reduction of MYL2 expression compared to an unaffected control. In vitro overexpression studies further indicate that the MYL2-fs variant is actively degraded. In contrast, an HCM-associated missense variant (MYL2:p.Gly162Arg) and three other MYL2 stop-gain variants (p.E22*, p.K62*, p.E97*) that result in loss of the EF domains are stably expressed but show impaired localization. The degradation of the MYL2-fs can be rescued by inhibiting the cell’s proteasome function supporting a post-translational effect of the variant. In vivo rescue experiments with a Drosophila MYL2-homolog (Mlc2) knockdown model indicate that neither the MYL2-fs nor the MYL2:p.Gly162Arg variant supports normal cardiac function. The tools that we have generated provide a rapid screening platform for functional assessment of variants of unknown significance in MYL2. Our study supports an autosomal recessive model of inheritance for MYL2 loss-of-function variants in infantile HCM and highlights the variant-specific molecular differences found in MYL2-associated cardiomyopathy. We report a novel frameshift variant in MYL2 that is associated with a severe form of infantile-onset hypertrophic cardiomyopathy. The impact of the variant is only observed in the recessive form of the disease found in the proband and not in the parents who are carriers of the variant. This contrasts with other dominant variants in MYL2 that are associated with cardiomyopathies. We compared the stability of this variant to that of other cardiomyopathy associated MYL2 variants and found molecular differences that correlated with disease pathology. We also show different protein domain requirements for stability and localization of MYL2 in cardiomyocytes. Furthermore, we used a fly model to demonstrate functional deficits due to the variant in the developing heart. Overall, our study shows a molecular mechanism by which loss-of-function variants in MYL2 are recessive while missense variants are dominant. We highlight the use of exome sequencing and functional testing to assist in the diagnosis of rare forms of disease where pathogenicity of the variant is not obvious. The new tools we developed for in vitro functional study and the fly fluorescent reporter analysis will permit rapid analysis of MYL2 variants of unknown significance.
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Affiliation(s)
- Sathiya N. Manivannan
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Sihem Darouich
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Laboratory of Human Genetics, Tunis, Tunisia
- * E-mail: (SD); (VG)
| | - Aida Masmoudi
- University of Tunis El Manar, Faculty of Medicine of Tunis, Department of Embryo-Fetopathology, Maternity and Neonatology Center, Tunis, Tunisia
| | - David Gordon
- Institute for Genomic Medicine at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Gloria Zender
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Zhe Han
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sara Fitzgerald-Butt
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Peter White
- Institute for Genomic Medicine at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Kim L. McBride
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Maher Kharrat
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Laboratory of Human Genetics, Tunis, Tunisia
| | - Vidu Garg
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (SD); (VG)
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22
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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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23
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Batzner A, Seggewiß H. [Hypertrophic cardiomyopathy]. Herz 2020; 45:233-242. [PMID: 32185419 DOI: 10.1007/s00059-020-04899-y] [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: 11/26/2022]
Abstract
Hypertrophic cardiomyopathy is the most common genetically determined cardiac disease with a prevalence of 0.2-0.6%. The most important pathophysiological phenomenon is dynamic obstruction predominantly of the left ventricular outflow tract in 70% of the patients. Clinical symptoms (e.g. dyspnea, angina pectoris and syncope) are extremely variable depending on changes in preload and afterload and an increased risk of sudden cardiac death particularly in younger patients. The diagnostic measures should be carried out with respect to a prognostic and symptomatic treatment with implantation of an implantable cardioverter defibrillator (ICD) in cases of increased risk of sudden cardiac death. When medication treatment fails, first-line treatment consists of septal ablation and surgical myectomy as a supplementary measure, depending on the underlying morphology and experience of the surgeon.
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Affiliation(s)
- Angelika Batzner
- Deutsches Zentrum für Herzinsuffizienz, Am Schwarzenberg 15, Haus 15A, Würzburg, 97078, Deutschland
| | - Hubert Seggewiß
- Deutsches Zentrum für Herzinsuffizienz, Am Schwarzenberg 15, Haus 15A, Würzburg, 97078, Deutschland.
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24
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Abu-Khousa M, Fiegle DJ, Sommer ST, Minabari G, Milting H, Heim C, Weyand M, Tomasi R, Dendorfer A, Volk T, Seidel T. The Degree of t-System Remodeling Predicts Negative Force-Frequency Relationship and Prolonged Relaxation Time in Failing Human Myocardium. Front Physiol 2020; 11:182. [PMID: 32231589 PMCID: PMC7083140 DOI: 10.3389/fphys.2020.00182] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/17/2020] [Indexed: 01/28/2023] Open
Abstract
The normally positive cardiac force-frequency relationship (FFR) becomes flat or negative in chronic heart failure (HF). Here we explored if remodeling of the cardiomyocyte transverse tubular system (t-system) is associated with alterations in FFR and contractile kinetics in failing human myocardium. Left-ventricular myocardial slices from 13 failing human hearts were mounted into a biomimetic culture setup. Maximum twitch force (F), 90% contraction duration (CD90), time to peak force (TTP) and time to relaxation (TTR) were determined at 37°C and 0.2–2 Hz pacing frequency. F1Hz/F0.5Hz and F2Hz/F0.5Hz served as measures of FFR, intracellular cardiomyocyte t-tubule distance (ΔTT) as measure of t-system remodeling. Protein levels of SERCA2, NCX1, and PLB were quantified by immunoblotting. F1Hz/F0.5Hz (R2 = 0.82) and F2Hz/F0.5Hz (R2 = 0.5) correlated negatively with ΔTT, i.e., samples with severe t-system loss exhibited a negative FFR and reduced myocardial wall tension at high pacing rates. PLB levels also predicted F1Hz/F0.5Hz, but to a lesser degree (R2 = 0.49), whereas NCX1 was not correlated (R2 = 0.02). CD90 correlated positively with ΔTT (R2 = 0.39) and negatively with SERCA2/PLB (R2 = 0.42), indicating that both the t-system and SERCA activity are important for contraction kinetics. Surprisingly, ΔTT was not associated with TTP (R2 = 0) but rather with TTR (R2 = 0.5). This became even more pronounced when interaction with NCX1 expression was added to the model (R2 = 0.79), suggesting that t-system loss impairs myocardial relaxation especially when NCX1 expression is low. The degree of t-system remodeling predicts FFR inversion and contraction slowing in failing human myocardium. Moreover, together with NCX, the t-system may be important for myocardial relaxation.
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Affiliation(s)
- Maha Abu-Khousa
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Dominik J Fiegle
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Sophie T Sommer
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ghazali Minabari
- Department of Cardiac Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr University Bochum, Bad Oeynhausen, Germany
| | - Christian Heim
- Department of Cardiac Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Weyand
- Department of Cardiac Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Roland Tomasi
- Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany.,Department of Anaesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Andreas Dendorfer
- Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Tilmann Volk
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Thomas Seidel
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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25
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Risk stratification in hypertrophic cardiomyopathy. Herz 2020; 45:50-64. [PMID: 29696341 DOI: 10.1007/s00059-018-4700-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/15/2018] [Accepted: 03/24/2018] [Indexed: 12/20/2022]
Abstract
Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). The greatest challenge in the management of HCM is identifying those at increased risk, since an implantable cardioverter-defibrillator (ICD) is a potentially life-saving therapy. We sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting data on risk stratification, with balanced guidance regarding rational clinical decision-making. Additionally, we sought to determine the status of the current implementation of guidelines compiled by HCM experts worldwide. The HCM Risk-SCD model helps improve the risk stratification of HCM patients for primary prevention of SCD by calculating an individual risk estimate that contributes to the clinical decision-making process. Improved risk stratification is important for decision-making before ICD implantation for the primary prevention of SCD.
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26
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Lyon A, Mincholé A, Bueno-Orovio A, Rodriguez B. Improving the clinical understanding of hypertrophic cardiomyopathy by combining patient data, machine learning and computer simulations: A case study. Morphologie 2019; 103:169-179. [PMID: 31570308 PMCID: PMC6913520 DOI: 10.1016/j.morpho.2019.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 01/02/2023]
Abstract
In this paper, we present how, by combining electrocardiogram and imaging data, machine learning and high performance computing simulations, we identified four phenotypes in hypertrophic cardiomyopathy (HCM), with differences in arrhythmic risk, and provided two distinct possible mechanisms that may explain the heterogeneity of HCM manifestation. This led to a better HCM patient stratification and understanding of the underlying disease mechanisms, providing a step further towards tailored HCM patient management and treatment.
Most patients with hypertrophic cardiomyopathy (HCM), the most common genetic cardiac disease, remain asymptomatic, but others may suffer from sudden cardiac death. A better identification of those patients at risk, together with a better understanding of the mechanisms leading to arrhythmia, are crucial to target high-risk patients and provide them with appropriate treatment. However, this currently remains a challenge. In this paper, we present a successful example of implementing computational techniques for clinically-relevant applications. By combining electrocardiogram and imaging data, machine learning and high performance computing simulations, we identified four phenotypes in HCM, with differences in arrhythmic risk, and provided two distinct possible mechanisms that may explain the heterogeneity of HCM manifestation. This led to a better HCM patient stratification and understanding of the underlying disease mechanisms, providing a step further towards tailored HCM patient management and treatment.
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Affiliation(s)
- A Lyon
- Department of Computer Science, University of Oxford, Oxford, United Kingdom; Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, Netherlands
| | - A Mincholé
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - A Bueno-Orovio
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - B Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom.
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27
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Khalique Z, Pennell D. Diffusion tensor cardiovascular magnetic resonance. Postgrad Med J 2019; 95:433-438. [DOI: 10.1136/postgradmedj-2019-136429] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/16/2019] [Accepted: 04/28/2019] [Indexed: 11/03/2022]
Abstract
Cardiac structure and function are complex and inter-related. Current in vivo techniques assess the heart on a macroscopic scale, but a novel technique called diffusion tensor cardiovascular magnetic resonance (DT-CMR) can now assess the cardiac microstructure non-invasively. It provides information on the helical arrangement of cardiomyocytes that drives torsion and offers dynamic assessment of the sheetlets (aggregated cardiomyocytes) that rotate through the cardiac cycle to facilitate wall thickening. Through diffusion biomarkers, the expansion and organisation of the underlying myocardium can be described. DT-CMR has already identified novel microstructural abnormalities in cardiomyopathy, and ischaemic and congenital heart disease. This new knowledge supports the potential of DT-CMR to improve diagnostics and prognostication in various cardiac diseases.
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28
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Miller RJH, Heidary S, Pavlovic A, Schlachter A, Dash R, Fleischmann D, Ashley EA, Wheeler MT, Yang PC. Defining genotype-phenotype relationships in patients with hypertrophic cardiomyopathy using cardiovascular magnetic resonance imaging. PLoS One 2019; 14:e0217612. [PMID: 31199839 PMCID: PMC6568393 DOI: 10.1371/journal.pone.0217612] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/16/2019] [Indexed: 01/28/2023] Open
Abstract
PURPOSE HCM is the most common inherited cardiomyopathy. Historically, there has been poor correlation between genotype and phenotype. However, CMR has the potential to more accurately assess disease phenotype. We characterized phenotype with CMR in a cohort of patients with confirmed HCM and high prevalence of genetic testing. METHODS Patients with a diagnosis of HCM, who had undergone contrast-enhanced CMR were identified. Left ventricular mass index (LVMI) and volumes were measured from steady-state free precession sequences. Late gadolinium enhancement (LGE) was quantified using the full width, half maximum method. All patients were prospectively followed for the development of septal reduction therapy, arrhythmia or death. RESULTS We included 273 patients, mean age 51.2 ± 15.5, 62.9% male. Of those patients 202 (74.0%) underwent genetic testing with 90 pathogenic, likely pathogenic, or rare variants and 13 variants of uncertain significance identified. Median follow-up was 1138 days. Mean LVMI was 82.7 ± 30.6 and 145 patients had late gadolinium enhancement (LGE). Patients with beta-myosin heavy chain (MYH7) mutations had higher LV ejection fraction (68.8 vs 59.1, p<0.001) than those with cardiac myosin binding protein C (MYBPC3) mutations. Patients with MYBPC3 mutations were more likely to have LVEF < 55% (29.7% vs 4.9%, p = 0.005) or receive a defibrillator than those with MYH7 mutations (54.1% vs 26.8%, p = 0.020). CONCLUSIONS We found that patients with MYBPC3 mutations were more likely to have impaired ventricular function and may be more prone to arrhythmic events. Larger studies using CMR phenotyping may be capable of identifying additional characteristics associated with less frequent genetic causes of HCM.
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Affiliation(s)
- Robert J. H. Miller
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Shahriar Heidary
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Aleksandra Pavlovic
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Audrey Schlachter
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Rajesh Dash
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Dominik Fleischmann
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Euan A. Ashley
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Matthew T. Wheeler
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Phillip C. Yang
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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29
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Tian H, Yang C, Song Y, Wang H, Yuan J, Cui J, Liu S, Hu F, Yang W, Jiang X, Qiao S. Microvascular Rarefaction and Myocardial Fibrosis in Hypertrophic Obstructive Cardiomyopathy. Cardiology 2019; 141:202-211. [DOI: 10.1159/000493005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/16/2018] [Indexed: 11/19/2022]
Abstract
Background: Hypertrophic obstructive cardiomyopathy (HOCM) is a myocardial disease characterized by fibrosis and microvascular ischemia. Microvessels play a critical role in myocardial fibrosis in HOCM. However, it remains unclear whether or not myocardial fibrosis is associated with microvascular density (MVD) changes. Objective: The aim of the present study was to investigate whether a reduction in MVD is related to myocardial fibrosis in HOCM cardiac samples. Methods: We analyzed MVD and fibrosis in myectomy left ventricular (LV) septal wall specimens from 53 HOCM patients. Control myocardium from the LV septal wall was collected at autopsy of 9 individuals who died of noncardiac causes. Results: The fibrosis ratio (% area) in HOCM was higher and the MVD was lower than that in control subjects (i.e., 12.7 ± 10.0 vs. 4.0 ± 1.4%, p = 0.012, and 480.9 ± 206.7 vs. 1,425 ± 221/mm2, p < 0.001). Patients with mild fibrosis had a higher MVD than patients with moderate fibrosis (i.e., 568.2 ± 214.8 vs. 403.2 ± 167.8/mm2, p = 0.006) and patients with severe fibrosis (i.e., 568.2 ± 214.8 vs. 378.6 ± 154.0/mm2, p = 0.024). Furthermore, a significant negative correlation was found between myocardial fibrosis and MVD in HOCM patients (r = –0.40, p = 0.003), which was also found in mild fibrosis (r = –0.40, p = 0.043), moderate fibrosis (r = –0.50, p = 0.024), and severe fibrosis (r = –0.24, p = 0.61), although no significant differences were observed in severe fibrosis. Additionally, we demonstrated that late gadolinium enhancement was negatively correlated with MVD (r = –0.37, p = 0.03) and positively correlated with fibrosis (r = 0.44, p = 0.01). Conclusion: HOCM patients had a higher myocardial fibrosis ratio and a lower MVD. The severity of myocardial fibrosis was negatively correlated with MVD in HOCM. These findings showed that a reduced MVD may contribute to myocardial fibrosis in HOCM.
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30
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Kraft T, Montag J. Altered force generation and cell-to-cell contractile imbalance in hypertrophic cardiomyopathy. Pflugers Arch 2019; 471:719-733. [PMID: 30740621 PMCID: PMC6475633 DOI: 10.1007/s00424-019-02260-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/20/2019] [Indexed: 01/18/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is mainly caused by mutations in sarcomeric proteins. Thirty to forty percent of identified mutations are found in the ventricular myosin heavy chain (β-MyHC). A common mechanism explaining how numerous mutations in several different proteins induce a similar HCM-phenotype is unclear. It was proposed that HCM-mutations cause hypercontractility, which for some mutations is thought to result from mutation-induced unlocking of myosin heads from a so-called super-relaxed state (SRX). The SRX was suggested to be related to the "interacting head motif," i.e., pairs of myosin heads folded back onto their S2-region. Here, we address these structural states of myosin in context of earlier work on weak binding cross-bridges. However, not all HCM-mutations cause hypercontractility and/or are involved in the interacting head motif. But most likely, all mutations alter the force generating mechanism, yet in different ways, possibly including inhibition of SRX. Such functional-hyper- and hypocontractile-changes are the basis of our previously proposed concept stating that contractile imbalance due to unequal fractions of mutated and wildtype protein among individual cardiomyocytes over time will induce cardiomyocyte disarray and fibrosis, hallmarks of HCM. Studying β-MyHC-mutations, we found substantial contractile variability from cardiomyocyte to cardiomyocyte within a patient's myocardium, much higher than in controls. This was paralleled by a similarly variable fraction of mutant MYH7-mRNA (cell-to-cell allelic imbalance), due to random, burst-like transcription, independent for mutant and wildtype MYH7-alleles. Evidence suggests that HCM-mutations in other sarcomeric proteins follow the same disease mechanism.
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Affiliation(s)
- Theresia Kraft
- Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Judith Montag
- Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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31
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Jacobson JT. Arrhythmia Evaluation and Management. Cardiol Clin 2019; 37:55-62. [DOI: 10.1016/j.ccl.2018.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Rigopoulos AG, Ali M, Abate E, Matiakis M, Melnyk H, Mavrogeni S, Leftheriotis D, Bigalke B, Noutsias M. Review on sudden death risk reduction after septal reduction therapies in hypertrophic obstructive cardiomyopathy. Heart Fail Rev 2019; 24:359-366. [DOI: 10.1007/s10741-018-09767-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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33
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Hypertrophic cardiomyopathy-linked variants of cardiac myosin-binding protein C3 display altered molecular properties and actin interaction. Biochem J 2018; 475:3933-3948. [PMID: 30446606 DOI: 10.1042/bcj20180685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 12/31/2022]
Abstract
The most common inherited cardiac disorder, hypertrophic cardiomyopathy (HCM), is characterized by thickening of heart muscle, for which genetic mutations in cardiac myosin-binding protein C3 (c-MYBPC3) gene, is the leading cause. Notably, patients with HCM display a heterogeneous clinical presentation, onset and prognosis. Thus, delineating the molecular mechanisms that explain how disparate c-MYBPC3 variants lead to HCM is essential for correlating the impact of specific genotypes on clinical severity. Herein, five c-MYBPC3 missense variants clinically associated with HCM were investigated; namely V1 (R177H), V2 (A216T), V3 (E258K), V4 (E441K) and double mutation V5 (V3 + V4), all located within the C1 and C2 domains of MyBP-C, a region known to interact with sarcomeric protein, actin. Injection of the variant complementary RNAs in zebrafish embryos was observed to recapitulate phenotypic aspects of HCM in patients. Interestingly, V3- and V5-cRNA injection produced the most severe zebrafish cardiac phenotype, exhibiting increased diastolic/systolic myocardial thickness and significantly reduced heart rate compared with control zebrafish. Molecular analysis of recombinant C0-C2 protein fragments revealed that c-MYBPC3 variants alter the C0-C2 domain secondary structure, thermodynamic stability and importantly, result in a reduced binding affinity to cardiac actin. V5 (double mutant), displayed the greatest protein instability with concomitant loss of actin-binding function. Our study provides specific mechanistic insight into how c-MYBPC3 pathogenic variants alter both functional and structural characteristics of C0-C2 domains leading to impaired actin interaction and reduced contractility, which may provide a basis for elucidating the disease mechanism in HCM patients with c- MYBPC3 mutations.
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34
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Lyon A, Bueno-Orovio A, Zacur E, Ariga R, Grau V, Neubauer S, Watkins H, Rodriguez B, Mincholé A. Electrocardiogram phenotypes in hypertrophic cardiomyopathy caused by distinct mechanisms: apico-basal repolarization gradients vs. Purkinje-myocardial coupling abnormalities. Europace 2018; 20:iii102-iii112. [PMID: 30476051 PMCID: PMC6251182 DOI: 10.1093/europace/euy226] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 09/27/2018] [Indexed: 12/13/2022] Open
Abstract
AIMS To identify key structural and electrophysiological features explaining distinct electrocardiogram (ECG) phenotypes in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS Human heart-torso anatomical models were constructed from cardiac magnetic resonance (CMR) images of HCM patients, representative of ECG phenotypes identified previously. High performance computing simulations using bidomain models were conducted to dissect key features explaining the ECG phenotypes with increased HCM Risk-SCD scores, namely Group 1A, characterized by normal QRS but inverted T waves laterally and coexistence of apical and septal hypertrophy; and Group 3 with marked QRS abnormalities (deep and wide S waves laterally) and septal hypertrophy. Hypertrophic cardiomyopathy abnormalities characterized from CMR, such as hypertrophy, tissue microstructure alterations, abnormal conduction system, and ionic remodelling, were selectively included to assess their influence on ECG morphology. Electrocardiogram abnormalities could not be explained by increased wall thickness nor by local conduction abnormalities associated with fibre disarray or fibrosis. Inverted T wave with normal QRS (Group 1A) was obtained with increased apico-basal repolarization gradient caused by ionic remodelling in septum and apex. Lateral QRS abnormalities (Group 3) were only recovered with abnormal Purkinje-myocardium coupling. CONCLUSION Two ECG-based HCM phenotypes are explained by distinct mechanisms: ionic remodelling and action potential prolongation in hypertrophied apical and septal areas lead to T wave inversion with normal QRS complexes, whereas abnormal Purkinje-myocardial coupling causes abnormal QRS morphology in V4-V6. These findings have potential implications for patients' management as they point towards different arrhythmia mechanisms in different phenotypes.
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Affiliation(s)
- Aurore Lyon
- Department of Computer Science, University of Oxford, Wolfson Building, Parks Rd, Oxford, UK
| | - Alfonso Bueno-Orovio
- Department of Computer Science, University of Oxford, Wolfson Building, Parks Rd, Oxford, UK
| | - Ernesto Zacur
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, UK
| | - Rina Ariga
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Vicente Grau
- Institute of Biomedical Engineering (IBME), Department of Engineering Science, University of Oxford, Oxford, UK
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Wolfson Building, Parks Rd, Oxford, UK
- Corresponding author. Tel: +44 1865 610806; fax: 00441865273839. E-mail address:
| | - Ana Mincholé
- Department of Computer Science, University of Oxford, Wolfson Building, Parks Rd, Oxford, UK
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Weissler-Snir A, Adler A, Williams L, Gruner C, Rakowski H. Prevention of sudden death in hypertrophic cardiomyopathy: bridging the gaps in knowledge. Eur Heart J 2018; 38:1728-1737. [PMID: 27371714 DOI: 10.1093/eurheartj/ehw268] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/01/2016] [Indexed: 12/12/2022] Open
Abstract
Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). Although the annual rate of SCD in the general HCM population is <1% per year according to contemporary series, there is still a small subset of patients who are at increased risk of SCD. The greatest challenge in the management of HCM is identifying those at increased risk as an implantable cardioverter defibrillator is a potentially life-saving therapy. In this review, we sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting European and American recommendations on risk stratification, with balanced guidance with regards to rational clinical decision making. Additionally, we sought to learn more on the actual implementation of the guidelines by HCM experts worldwide.
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Affiliation(s)
- Adaya Weissler-Snir
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Arnon Adler
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Lynne Williams
- Papworth Hospital NHS Foundation Trust, Papworth Everard, Cambridge, UK
| | - Christiane Gruner
- Division of Cardiology, Cardiovascular Centre, University Hospital Zurich, Zurich, Switzerland
| | - Harry Rakowski
- Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, ON, Canada
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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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Ad N, Wei LM. It is the time for a heart team approach for patients with hypertrophic cardiomyopathy. J Thorac Cardiovasc Surg 2017; 154:e105-e106. [DOI: 10.1016/j.jtcvs.2017.08.083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 08/26/2017] [Indexed: 11/16/2022]
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Viswanathan SK, Sanders HK, McNamara JW, Jagadeesan A, Jahangir A, Tajik AJ, Sadayappan S. Hypertrophic cardiomyopathy clinical phenotype is independent of gene mutation and mutation dosage. PLoS One 2017; 12:e0187948. [PMID: 29121657 PMCID: PMC5679632 DOI: 10.1371/journal.pone.0187948] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/27/2017] [Indexed: 12/27/2022] Open
Abstract
Over 1,500 gene mutations are known to cause hypertrophic cardiomyopathy (HCM). Previous studies suggest that cardiac β-myosin heavy chain (MYH7) gene mutations are commonly associated with a more severe phenotype, compared to cardiac myosin binding protein-C (MYBPC3) gene mutations with milder phenotype, incomplete penetrance and later age of onset. Compound mutations can worsen the phenotype. This study aimed to validate these comparative differences in a large cohort of individuals and families with HCM. We performed genome-phenome correlation among 80 symptomatic HCM patients, 35 asymptomatic carriers and 35 non-carriers, using an 18-gene clinical diagnostic HCM panel. A total of 125 mutations were identified in 14 genes. MYBPC3 and MYH7 mutations contributed to 50.0% and 24.4% of the HCM patients, respectively, suggesting that MYBPC3 mutations were the most frequent cause of HCM in our cohort. Double mutations were found in only nine HCM patients (7.8%) who were phenotypically indistinguishable from single-mutation carriers. Comparisons of clinical parameters of MYBPC3 and MYH7 mutants were not statistically significant, but asymptomatic carriers had high left ventricular ejection fraction and diastolic dysfunction when compared to non-carriers. The presence of double mutations increases the risk for symptomatic HCM with no change in severity, as determined in this study subset. The pathologic effects of MYBPC3 and MYH7 were found to be independent of gene mutation location. Furthermore, HCM pathology is independent of protein domain disruption in both MYBPC3 and MYH7. These data provide evidence that MYBPC3 mutations constitute the preeminent cause of HCM and that they are phenotypically indistinguishable from HCM caused by MYH7 mutations.
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Affiliation(s)
- Shiv Kumar Viswanathan
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Heather K. Sanders
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - James W. McNamara
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Aravindakshan Jagadeesan
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Arshad Jahangir
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - A. Jamil Tajik
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - Sakthivel Sadayappan
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
- * E-mail:
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40
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El volumen extracelular no se asocia a arritmias malignas en miocardiopatía hipertrófica de alto riesgo. Rev Esp Cardiol (Engl Ed) 2017. [DOI: 10.1016/j.recesp.2017.01.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Liu H, Pozios I, Haileselassie B, Nowbar A, Sorensen LL, Phillip S, Lu DY, Ventoulis I, Luo H, Abraham MR, Abraham TP. Role of Global Longitudinal Strain in Predicting Outcomes in Hypertrophic Cardiomyopathy. Am J Cardiol 2017; 120:670-675. [PMID: 28687124 DOI: 10.1016/j.amjcard.2017.05.039] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/15/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022]
Abstract
Global longitudinal strain (GLS) is a sensitive indicator of global left ventricular function particularly in those with normal ejection fraction. We examined the potential value of GLS in predicting outcomes in hypertrophic cardiomyopathy (HC). Conventional and strain echocardiography was performed in 400 patients with HC followed for a median 3.1 years (interquartile range 1.2 to 5.6). Peak systolic strain from 3 apical views was averaged to calculate GLS. Patients were divided based on a previously published cutoff value of -16%. Additionally, we identified 4 HC subgroups based on GLS: GLS ≤ -20%, -20% < GLS ≤ -16%, -16% < GLS ≤ -10%, and GLS > -10%. The primary end point was a composite of new-onset sustained ventricular tachycardia/fibrillation, heart failure, cardiac transplantation, and all-cause death. Patients with GLS > -16% had significantly more events (17% vs 7%, p = 0.002). In the 4-group analysis, event rates increased with worsening GLS (5%, 7%, 14%, and 33%, respectively, p = 0.001). Event-free survival was significantly superior in those with GLS ≤ -16% versus GLS > -16% (p = 0.004); similarly, GLS > -10% portended a significantly worse event-free survival compared with each of the other 3 groups (p <0.01 for all pairwise comparisons). By univariate and multivariate Cox regression analysis, GLS remained significantly associated with the composite end point. GLS > -10% had 4 times the risk of events compared with GLS ≤ -16% (p = 0.006). In conclusion, echo-based GLS is independently associated with outcomes in HC. Patients with GLS > -10% have significantly higher event rates.
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42
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Lu DY, Haileselassie B, Ventoulis I, Liu HY, Liang HY, Pozios I, Canepa M, Phillip S, Abraham MR, Abraham T. E/e′ ratio and outcome prediction in hypertrophic cardiomyopathy: the influence of outflow tract obstruction. Eur Heart J Cardiovasc Imaging 2017; 19:101-107. [DOI: 10.1093/ehjci/jex134] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 07/04/2017] [Indexed: 01/05/2023] Open
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Marian AJ, van Rooij E, Roberts R. Genetics and Genomics of Single-Gene Cardiovascular Diseases: Common Hereditary Cardiomyopathies as Prototypes of Single-Gene Disorders. J Am Coll Cardiol 2017; 68:2831-2849. [PMID: 28007145 DOI: 10.1016/j.jacc.2016.09.968] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/14/2016] [Accepted: 09/19/2016] [Indexed: 01/05/2023]
Abstract
This is the first of 2 review papers on genetics and genomics appearing as part of the series on "omics." Genomics pertains to all components of an organism's genes, whereas genetics involves analysis of a specific gene or genes in the context of heredity. The paper provides introductory comments, describes the basis of human genetic diversity, and addresses the phenotypic consequences of genetic variants. Rare variants with large effect sizes are responsible for single-gene disorders, whereas complex polygenic diseases are typically due to multiple genetic variants, each exerting a modest effect size. To illustrate the clinical implications of genetic variants with large effect sizes, 3 common forms of hereditary cardiomyopathies are discussed as prototypic examples of single-gene disorders, including their genetics, clinical manifestations, pathogenesis, and treatment. The genetic basis of complex traits is discussed in a separate paper.
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Affiliation(s)
- Ali J Marian
- Center for Cardiovascular Genetics, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, and Texas Heart Institute, Houston, Texas.
| | - Eva van Rooij
- Hubrecht Institute, KNAW and University Medical Center Utrecht, Utrecht, the Netherlands; Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Robert Roberts
- University of Arizona College of Medicine, Phoenix, Arizona
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Vega RB, Konhilas JP, Kelly DP, Leinwand LA. Molecular Mechanisms Underlying Cardiac Adaptation to Exercise. Cell Metab 2017; 25:1012-1026. [PMID: 28467921 PMCID: PMC5512429 DOI: 10.1016/j.cmet.2017.04.025] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/13/2017] [Accepted: 04/18/2017] [Indexed: 02/06/2023]
Abstract
Exercise elicits coordinated multi-organ responses including skeletal muscle, vasculature, heart, and lung. In the short term, the output of the heart increases to meet the demand of strenuous exercise. Long-term exercise instigates remodeling of the heart including growth and adaptive molecular and cellular re-programming. Signaling pathways such as the insulin-like growth factor 1/PI3K/Akt pathway mediate many of these responses. Exercise-induced, or physiologic, cardiac growth contrasts with growth elicited by pathological stimuli such as hypertension. Comparing the molecular and cellular underpinnings of physiologic and pathologic cardiac growth has unveiled phenotype-specific signaling pathways and transcriptional regulatory programs. Studies suggest that exercise pathways likely antagonize pathological pathways, and exercise training is often recommended for patients with chronic stable heart failure or following myocardial infarction. Herein, we summarize the current understanding of the structural and functional cardiac responses to exercise as well as signaling pathways and downstream effector molecules responsible for these adaptations.
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Affiliation(s)
- Rick B Vega
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL 32827, USA
| | - John P Konhilas
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85724, USA
| | - Daniel P Kelly
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL 32827, USA
| | - Leslie A Leinwand
- Molecular, Cellular and Developmental Biology, BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA.
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Mirelis JG, Sánchez-González J, Zorio E, Ripoll-Vera T, Salguero-Bodes R, Filgueiras-Rama D, González-López E, Gallego-Delgado M, Fernández-Jiménez R, Soleto MJ, Núñez J, Pizarro G, Sanz J, Fuster V, García-Pavía P, Ibáñez B. Myocardial Extracellular Volume Is Not Associated With Malignant Ventricular Arrhythmias in High-risk Hypertrophic Cardiomyopathy. ACTA ACUST UNITED AC 2017; 70:933-940. [PMID: 28341414 DOI: 10.1016/j.rec.2017.01.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 01/25/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION AND OBJECTIVES Myocardial interstitial fibrosis, a hallmark of hypertrophic cardiomyopathy (HCM), has been proposed as an arrhythmic substrate. Fibrosis is associated with increased extracellular volume (ECV), which can be quantified by computed tomography (CT). We aimed to analyze the association between CT-determined ECV and malignant ventricular arrhythmias. METHODS A retrospective case-control observational study was conducted in HCM patients with implantable cardioverter-defibrillator, undergoing a CT-protocol with continuous iodine contrast infusion to determine equilibrium ECV. Left ventricular septal and lateral CT-determined ECV was compared between prespecified cases (malignant arrhythmia any time before CT scan) and controls (no prior malignant arrhythmias) and among ECV tertiles. RESULTS A total of 78 implantable cardioverter-defibrillator HCM patients were included; 24 were women, with a mean age of 52.1 ± 15.6 years. Mean ECV ± standard deviation in the septal left ventricular wall and was 29.8% ± 6.3% in cases (n = 24) vs 31.9% ± 8.5% in controls (n = 54); P = .282. Mean ECV in the lateral wall was 24.5% ± 6.8% in cases vs 28.2% ± 7.4% in controls; P = .043. On comparison of the entire population according to septal ECV tertiles, no significant differences were found in the number of patients receiving appropriate shocks. Conversely, we found a trend (P = .056) for a higher number of patients receiving appropriate shocks in the lateral ECV lowest tertile. CONCLUSIONS Extracellular volume was not increased in implantable cardioverter-defibrillator HCM patients with malignant ventricular arrhythmias vs those without arrhythmias. Our findings do not support the use of ECV (a surrogate of diffuse fibrosis) as a predictor of arrhythmias in high-risk HCM patients.
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Affiliation(s)
- Jesús G Mirelis
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, Hospital Universitario Puerta de Hierro, Majahonda, Madrid, Spain
| | - Javier Sánchez-González
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; Departamento de Ciencia Clínica, Philips Healthcare, Spain
| | - Esther Zorio
- Departamento de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Tomas Ripoll-Vera
- Departamento de Cardiología, Hospital de Son Llàtzer & IdISPa, Palma de Mallorca, Spain
| | | | - David Filgueiras-Rama
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, Hospital Universitario Clínico San Carlos, Madrid, Spain
| | - Esther González-López
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, Hospital Universitario Puerta de Hierro, Majahonda, Madrid, Spain
| | - María Gallego-Delgado
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain
| | - Rodrigo Fernández-Jiménez
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Department of Cardiology, The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, United States
| | - María Jesús Soleto
- Departamento de Cardiología, Hospital de Son Llàtzer & IdISPa, Palma de Mallorca, Spain
| | - Juana Núñez
- Departamento de Cardiología, Hospital de Son Llàtzer & IdISPa, Palma de Mallorca, Spain
| | - Gonzalo Pizarro
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, Complejo Hospitalario Ruber Juan Bravo, Universidad Europea de Madrid, Madrid, Spain
| | - Javier Sanz
- Department of Cardiology, The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Valentín Fuster
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; Department of Cardiology, The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Pablo García-Pavía
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, Hospital Universitario Puerta de Hierro, Majahonda, Madrid, Spain
| | - Borja Ibáñez
- Área de Fisiopatología del Miocardio, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Instituto de Salud Carlos III, Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), Spain; Departamento de Cardiología, IIS-Hospital Fundación Jiménez Díaz, Madrid, Spain.
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Corona-Villalobos CP, Saha S, Pozios I, Hurtado-de-Mendoza Paz D, Sorensen L, Gonzalez Cordoba J, Dolores-Cerna K, Kamel IR, Mormontoy Laurel W, Bluemke DA, Abraham TP, Zimmerman SL, Abraham MR. Exercise-QTc is associated with diffuse interstitial fibrosis reflected by lower approximated T1 relaxation time in hypertrophic cardiomyopathy patients. J Electrocardiol 2017; 50:484-490. [PMID: 28292523 DOI: 10.1016/j.jelectrocard.2017.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Celia P Corona-Villalobos
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 N Wolfe St, MRI 110B, Baltimore, MD, United States; Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Sudip Saha
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Iraklis Pozios
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - David Hurtado-de-Mendoza Paz
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Medicine, Cayetano Heredia University School of Medicine, Av. Honorio Delgado 430, San Martin de Porres, Lima, Peru
| | - Lars Sorensen
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jorge Gonzalez Cordoba
- Department of Medicine, Cayetano Heredia University School of Medicine, Av. Honorio Delgado 430, San Martin de Porres, Lima, Peru
| | - Ketty Dolores-Cerna
- Department of Statistics, Cayetano Heredia University School of Medicine, Av. Honorio Delgado 430, San Martin de Porres, Lima, Peru
| | - Ihab R Kamel
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 N Wolfe St, MRI 110B, Baltimore, MD, United States
| | - Wilfredo Mormontoy Laurel
- Department of Statistics, Cayetano Heredia University School of Medicine, Av. Honorio Delgado 430, San Martin de Porres, Lima, Peru
| | - David A Bluemke
- Radiology and Imaging Sciences, National Institute of Health Clinical Center, Building 10, Clinical Center 10 Center Drive, MSC 1074, Bethesda, MD, United States
| | - Theodore P Abraham
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Stefan L Zimmerman
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 N Wolfe St, MRI 110B, Baltimore, MD, United States
| | - M Roselle Abraham
- Hypertrophic Cardiomyopathy Center of Excellence, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
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47
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Quick AP, Landstrom AP, Wang Q, Beavers DL, Reynolds JO, Barreto-Torres G, Tran V, Showell J, Philippen LE, Morris SA, Skapura D, Bos JM, Pedersen SE, Pautler RG, Ackerman MJ, Wehrens XHT. Novel junctophilin-2 mutation A405S is associated with basal septal hypertrophy and diastolic dysfunction. ACTA ACUST UNITED AC 2017; 2:56-67. [PMID: 28393127 PMCID: PMC5384575 DOI: 10.1016/j.jacbts.2016.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A JPH2 A405S mutation was found in a human HCM patient. A novel echocardiographic imaging plane revealed septal hypertrophy in a mouse model bearing the human JPH2 mutation, thereby causally linking it to HCM pathogenesis. This alpha helical JPH2 mutation resulted in decreased transverse tubule regularity and aberrant calcium handling in septal cardiomyocytes.
Junctophilin-2 (JPH2) is a structural calcium (Ca2+) handling protein, which approximates the cardiomyocyte transverse tubules (TTs) to the sarcoplasmic reticulum. This facilitates communication of the voltage-gated Ca2+ channel and the ryanodine receptor RyR2. A human patient with hypertrophic cardiomyopathy was positive for a JPH2 mutation substituting alanine-405—located within the alpha helix domain—with a serine (A405S). Using a novel mouse echocardiography plane, we found that mice bearing this JPH2 mutation developed increased subvalvular septal thickness. Cardiomyocytes from the septa of these mice displayed irregular TTs and abnormal Ca2+ handling including increased SERCA activity.
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Affiliation(s)
- Ann P Quick
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Andrew P Landstrom
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Qiongling Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - David L Beavers
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Julia O Reynolds
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Giselle Barreto-Torres
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Viet Tran
- Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Jordan Showell
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Leonne E Philippen
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Shaine A Morris
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Darlene Skapura
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - J Martijn Bos
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Steen E Pedersen
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Robia G Pautler
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Michael J Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA; Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
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48
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Relationship of Nonseptal Late Gadolinium Enhancement to Ventricular Tachyarrhythmia in Hypertrophic Cardiomyopathy. J Comput Assist Tomogr 2017; 41:768-771. [DOI: 10.1097/rct.0000000000000599] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Wilkie LJ, Smith K, Luis Fuentes V. Cardiac pathology findings in 252 cats presented for necropsy; a comparison of cats with unexpected death versus other deaths. J Vet Cardiol 2016; 17 Suppl 1:S329-40. [PMID: 26776590 DOI: 10.1016/j.jvc.2015.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 09/18/2015] [Accepted: 09/27/2015] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To report necropsy and myocardial histopathology in cats with unexpected death and expected death/euthanasia, comparing findings in 4 groups of cats: unexpected death with noncardiac disease (UD-NC); unexpected death with cardiac disease (UD-C); expected death/euthanasia due to noncardiac disease with incidental cardiac disease (OD + HD); and expected death/euthanasia due to congestive heart failure (CHF). ANIMALS Two hundred fifty-two cats undergoing necropsy at a single centre. METHODS Signalment, history, body weight, heart weight and myocardial thickness were obtained from medical records. Cardiac histopathology slides were reviewed blindly by a single observer. Data were analysed using a Chi squared, Fisher's exact, Kruskal-Wallis tests or ANOVA as appropriate. RESULTS Death at a veterinary clinic and suspected poisoning were the most common reasons for necropsy in 158 cats with an unexpected death. No cause other than cardiac disease was found in 87/158 (55.1%), with hypertrophic cardiomyopathy identified in 68/87 (78%) of UD-C cats. Expected deaths or euthanasia occurred in 27 cats with CHF and 67 cats with concurrent heart disease (OD + HD). Myofiber disarray, interstitial fibrosis, subendocardial fibrosis and intramural arteriolosclerosis were more prevalent in UD-C cats than in UD-NC cats, and subendocardial fibrosis and arteriolosclerosis were more prevalent in UD-C cats than in CHF and OD + HD cats. CONCLUSIONS Cardiac disease, and hypertrophic cardiomyopathy in particular, was commonly present in cats that died unexpectedly in this study population. Subendocardial fibrosis and intramural arteriolosclerosis were more common in cats with unexpected death with cardiac disease than in other cats.
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Affiliation(s)
- L J Wilkie
- Department of Clinical Sciences and Services, The Royal Veterinary College, UK
| | - K Smith
- Department of Pathology and Pathogen Biology, The Royal Veterinary College, UK
| | - V Luis Fuentes
- Department of Clinical Sciences and Services, The Royal Veterinary College, UK.
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50
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Sen-Chowdhry S, Jacoby D, Moon JC, McKenna WJ. Update on hypertrophic cardiomyopathy and a guide to the guidelines. Nat Rev Cardiol 2016; 13:651-675. [PMID: 27681577 DOI: 10.1038/nrcardio.2016.140] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM.
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Affiliation(s)
- Srijita Sen-Chowdhry
- Institute of Cardiovascular Science, University College London, Gower Street, London WC1E 6BT, UK.,Department of Epidemiology, Imperial College, St Mary's Campus, Norfolk Place, London W2 1NY, UK
| | - Daniel Jacoby
- Section of Cardiovascular Medicine, Yale School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - James C Moon
- Institute of Cardiovascular Science, University College London, Gower Street, London WC1E 6BT, UK.,Barts Heart Centre, St Bartholomew's Hospital, West Smithfield, London EC1A 7BE, UK
| | - William J McKenna
- Heart Hospital, Hamad Medical Corporation, Al Rayyan Road, Doha, Qatar
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