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Chockalingam P, Geetha TS, Nair S, Rajakumar N, Raja DC, Lokhandwala Y, Chaturvedi V, Selvaraj RJ, Ramasamy S, Sharda S, Sundar C, Anantharaman R. Results of comprehensive genetic testing in patients presenting to a multidisciplinary inherited heart disease clinic in India. Indian Heart J 2024:S0019-4832(24)00154-8. [PMID: 39009076 DOI: 10.1016/j.ihj.2024.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 07/04/2024] [Accepted: 07/12/2024] [Indexed: 07/17/2024] Open
Abstract
OBJECTIVES This study aims to analyze the results of comprehensive genetic testing in patients presenting to a dedicated multidisciplinary inherited heart disease clinic in India. METHODS All patients presenting to our clinic from August 2017 to October 2023 with a suspected inherited heart disease and consenting for genetic testing were included. The probands were grouped into familial cardiomyopathies namely hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), arrhythmogenic cardiomyopathy (ACM) and peripartum cardiomyopathy (PPCM), channelopathies namely congenital long QT syndrome (LQTS) and Brugada syndrome (BrS), and heritable connective tissue disorder namely Marfan Syndrome (MFS). Next generation sequencing (NGS) was used, and pre-test and post-test counseling were provided to probands and cascade screening offered to relatives. RESULTS Mean age of the subjects (n = 77; 48 probands, 29 relatives) was 43 ± 18 years, 68 % male and 44 % symptomatic, with 36 HCM, 3 DCM, 3 ACM, 1 PPCM, 3 LQTS, 1 BrS and 1 MFS probands. The diagnostic yield of NGS-based genetic testing was 31 %; variants of uncertain significance (VUS) were identified in 54 %; and 15 % were genotype-negative. Twenty-nine relatives from 18 families with HCM (n = 12), DCM (n = 3), ACM (n = 2) and MFS (n = 1) underwent genetic testing. The genotype positive probands/relatives and VUS carriers with strong disease phenotype and/or high risk variant were advised periodic follow-up; the remaining probands/relatives were discharged from further clinical surveillance. CONCLUSIONS Genetic testing guides treatment and follow-up of patients with inherited heart diseases and should be carried out in dedicated multidisciplinary clinics with expertise for counseling and cascade screening of family members.
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Affiliation(s)
- Priya Chockalingam
- Centre for Inherited Heart Disease, Department of Cardiology, Kauvery Hospital, Chennai, India.
| | - Thenral S Geetha
- Principal Scientist, Operations, Medgenome Labs, Bengaluru, India
| | - Sandhya Nair
- Senior Manager, Operations, Medgenome Labs, Bengaluru, India
| | - Nivedita Rajakumar
- Senior Genetic Counselor, Neuberg Centre for Genomic Medicine, Chennai, India
| | - Deep Chandh Raja
- Cardiac Electrophysiologist, Department of Cardiology, Kauvery Hospital, Chennai, India
| | - Yash Lokhandwala
- Cardiac Electrophysiologist, Holy Family Hospital, Mumbai, India
| | - Vivek Chaturvedi
- Senior Consultant & Professor of Cardiology, Amrita Institute of Medical Science and Research, Faridabad, India
| | - Raja J Selvaraj
- Professor of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Sakthivel Ramasamy
- Cardiac Electrophysiologist, Dr. Kamakshi Memorial Hospitals, Chennai, India
| | - Sheetal Sharda
- Director, Genomics Development and Implementation, Neuberg Centre for Genomic Medicine, Ahmedabad, India
| | - C Sundar
- Interventional Cardiologist, Department of Cardiology, Kauvery Hospital, Chennai, India
| | - R Anantharaman
- Centre for Inherited Heart Disease, Department of Cardiology, Kauvery Hospital, Chennai, India; Interventional Cardiologist, Department of Cardiology, Kauvery Hospital, Chennai, India
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Maron BJ, Rowin EJ, Maron MS. Advances in the Management of Hypertrophic Cardiomyopathy Leading to Low Disease-Related Mortality in 2023. Am J Cardiol 2024; 212S:S77-S82. [PMID: 38368039 DOI: 10.1016/j.amjcard.2023.10.073] [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: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 02/19/2024]
Abstract
Hypertrophic cardiomyopathy (HCM) is a relatively common often inherited heart disease encumbered throughout much of its almost 60-year history by the expectation of an unfavorable outcome with shortened longevity. However, it is notable that in 2023, most patients affected with HCM can now achieve normal or extended life expectancy without major disability because of a comprehensive constellation of management strategies that have evolved largely over the last 20 years. Distinct adverse disease pathways dictate high-benefit low-risk personalized treatments, without reliance on genomics and sarcomere mutations, including: primary prevention implantable defibrillators for sudden cardiac death prevention, surgical myectomy and percutaneous alcohol septal ablation to reverse heart failure symptoms, anticoagulation to prevent embolic stroke associated with concomitant atrial fibrillation, external defibrillation and hypothermia for out-of-hospital cardiac arrest, and heart transplant in a small patient subgroup with end-stage disease. Large cohort studies using these contemporary management strategies achieved remarkably low HCM-related mortality (0.5%/year) across all age groups, which is lower than in the other cardiac or noncardiac risks of living, and largely confined to nonobstructive patients with progressive heart failure, including those awaiting heart transplant.
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Affiliation(s)
- Barry J Maron
- HCM Center, Lahey Hospital and Medical Center, Burlington, Massachusetts.
| | - Ethan J Rowin
- HCM Center, Lahey Hospital and Medical Center, Burlington, Massachusetts
| | - Martin S Maron
- HCM Center, Lahey Hospital and Medical Center, Burlington, Massachusetts
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Chumakova OS, Baklanova TN, Milovanova NV, Zateyshchikov DA. Hypertrophic Cardiomyopathy in Underrepresented Populations: Clinical and Genetic Landscape Based on a Russian Single-Center Cohort Study. Genes (Basel) 2023; 14:2042. [PMID: 38002985 PMCID: PMC10671745 DOI: 10.3390/genes14112042] [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: 09/19/2023] [Revised: 10/30/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder characterized by marked clinical and genetic heterogeneity. Ethnic groups underrepresented in studies may have distinctive characteristics. We sought to evaluate the clinical and genetic landscape of Russian HCM patients. A total of 193 patients (52% male; 95% Eastern Slavic origin; median age 56 years) were clinically evaluated, including genetic testing, and prospectively followed to document outcomes. As a result, 48% had obstructive HCM, 25% had HCM in family, 21% were asymptomatic, and 68% had comorbidities. During 2.8 years of follow-up, the all-cause mortality rate was 2.86%/year. A total of 5.7% received an implantable cardioverter-defibrillator (ICD), and 21% had septal reduction therapy. A sequencing analysis of 176 probands identified 64 causative variants in 66 patients (38%); recurrent variants were MYBPC3 p.Q1233* (8), MYBPC3 p.R346H (2), MYH7 p.A729P (2), TPM1 p.Q210R (3), and FLNC p.H1834Y (2); 10 were multiple variant carriers (5.7%); 5 had non-sarcomeric HCM, ALPK3, TRIM63, and FLNC. Thin filament variant carriers had a worse prognosis for heart failure (HR = 7.9, p = 0.007). In conclusion, in the Russian HCM population, the low use of ICD and relatively high mortality should be noted by clinicians; some distinct recurrent variants are suspected to have a founder effect; and family studies on some rare variants enriched worldwide knowledge in HCM.
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Affiliation(s)
- Olga S. Chumakova
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
- E.I. Chazov National Medical Research Center for Cardiology, 121552 Moscow, Russia
| | - Tatiana N. Baklanova
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
| | | | - Dmitry A. Zateyshchikov
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
- E.I. Chazov National Medical Research Center for Cardiology, 121552 Moscow, Russia
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4
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Kuster DWD, Lynch TL, Barefield DY, Sivaguru M, Kuffel G, Zilliox MJ, Lee KH, Craig R, Namakkal-Soorappan R, Sadayappan S. Altered C10 domain in cardiac myosin binding protein-C results in hypertrophic cardiomyopathy. Cardiovasc Res 2019; 115:1986-1997. [PMID: 31050699 PMCID: PMC6872972 DOI: 10.1093/cvr/cvz111] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/04/2019] [Accepted: 04/25/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS A 25-base pair deletion in the cardiac myosin binding protein-C (cMyBP-C) gene (MYBPC3), proposed to skip exon 33, modifies the C10 domain (cMyBP-CΔC10mut) and is associated with hypertrophic cardiomyopathy (HCM) and heart failure, affecting approximately 100 million South Asians. However, the molecular mechanisms underlying the pathogenicity of cMyBP-CΔC10mutin vivo are unknown. We hypothesized that expression of cMyBP-CΔC10mut exerts a poison polypeptide effect leading to improper assembly of cardiac sarcomeres and the development of HCM. METHODS AND RESULTS To determine whether expression of cMyBP-CΔC10mut is sufficient to cause HCM and contractile dysfunction in vivo, we generated transgenic (TG) mice having cardiac-specific protein expression of cMyBP-CΔC10mut at approximately half the level of endogenous cMyBP-C. At 12 weeks of age, significant hypertrophy was observed in TG mice expressing cMyBP-CΔC10mut (heart weight/body weight ratio: 4.43 ± 0.11 mg/g non-transgenic (NTG) vs. 5.34 ± 0.25 mg/g cMyBP-CΔC10mut, P < 0.05). Furthermore, haematoxylin and eosin, Masson's trichrome staining, as well as second-harmonic generation imaging revealed the presence of significant fibrosis and a greater relative nuclear area in cMyBP-CΔC10mut hearts compared with NTG controls. M-mode echocardiography analysis revealed hypercontractile hearts (EF: 53.4%±2.9% NTG vs. 66.4% ± 4.7% cMyBP-CΔC10mut; P < 0.05) and early diastolic dysfunction (E/E': 28.7 ± 3.7 NTG vs. 46.3 ± 8.4 cMyBP-CΔC10mut; P < 0.05), indicating the presence of an HCM phenotype. To assess whether these changes manifested at the myofilament level, contractile function of single skinned cardiomyocytes was measured. Preserved maximum force generation and increased Ca2+-sensitivity of force generation were observed in cardiomyocytes from cMyBP-CΔC10mut mice compared with NTG controls (EC50: 3.6 ± 0.02 µM NTG vs. 2.90 ± 0.01 µM cMyBP-CΔC10mut; P < 0.0001). CONCLUSION Expression of cMyBP-C protein with a modified C10 domain is sufficient to cause contractile dysfunction and HCM in vivo.
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MESH Headings
- Animals
- Calcium Signaling
- Cardiomyopathy, Hypertrophic/genetics
- Cardiomyopathy, Hypertrophic/metabolism
- Cardiomyopathy, Hypertrophic/pathology
- Cardiomyopathy, Hypertrophic/physiopathology
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Disease Models, Animal
- Fibrosis
- Gene Expression Regulation
- Gene Regulatory Networks
- Genetic Predisposition to Disease
- Mice, Transgenic
- Mutation
- Myocardial Contraction
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Protein Domains
- Sarcomeres/genetics
- Sarcomeres/metabolism
- Sarcomeres/pathology
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/pathology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Remodeling
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Affiliation(s)
- Diederik W D Kuster
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Thomas L Lynch
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
| | - David Y Barefield
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
- Center for Genetic Medicine, Northwestern University, Chicago, IL, USA
| | - Mayandi Sivaguru
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Gina Kuffel
- Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
| | | | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rajasekaran Namakkal-Soorappan
- Molecular and Cellular Pathology, Department of Pathology, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sakthivel Sadayappan
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, USA
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Khanna S, Prasad K, Sharma VJ, Bewal NM. A chance encounter with a case of hypertrophic cardiomyopathy. Indian J Anaesth 2019; 63:1041-1042. [PMID: 31879432 PMCID: PMC6921320 DOI: 10.4103/ija.ija_504_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/24/2019] [Accepted: 09/22/2019] [Indexed: 11/04/2022] Open
Affiliation(s)
- Sangeeta Khanna
- Department of Anaesthesiology, Military Hospital Kirkee, Pune, Maharashtra, India
| | - Krishna Prasad
- Department of Anaesthesiology, Military Hospital Kirkee, Pune, Maharashtra, India
| | - Vipin J Sharma
- Department of Anaesthesiology, Military Hospital Kirkee, Pune, Maharashtra, India
| | - Nitul M Bewal
- Department of Medicine, Military Hospital Kirkee, Pune, Maharashtra, India
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Mattos BPE, Scolari FL, Torres MAR, Simon L, Freitas VCD, Giugliani R, Matte Ú. Prevalence and Phenotypic Expression of Mutations in the MYH7, MYBPC3 and TNNT2 Genes in Families with Hypertrophic Cardiomyopathy in the South of Brazil: A Cross-Sectional Study. Arq Bras Cardiol 2017; 107:257-265. [PMID: 27737317 PMCID: PMC5053194 DOI: 10.5935/abc.20160133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/24/2016] [Indexed: 02/04/2023] Open
Abstract
Background: Mutations in sarcomeric genes are found in 60-70% of individuals with familial forms of hypertrophic cardiomyopathy (HCM). However, this estimate refers to northern hemisphere populations. The molecular-genetic profile of HCM has been subject of few investigations in Brazil, particularly in the south of the country. Objective: To investigate mutations in the sarcomeric genes MYH7, MYBPC3 and TNNT2 in a cohort of HCM patients living in the extreme south of Brazil, and to evaluate genotype-phenotype associations. Methods: Direct DNA sequencing of all encoding regions of three sarcomeric genes was conducted in 43 consecutive individuals of ten unrelated families. Results: Mutations for CMH have been found in 25 (58%) patients of seven (70%) of the ten study families. Fourteen (56%) individuals were phenotype-positive. All mutations were missense, four (66%) in MYH7 and two (33%) in MYBPC3. We have not found mutations in the TNNT2 gene. Mutations in MYH7 were identified in 20 (47%) patients of six (60%) families. Two of them had not been previously described. Mutations in MYBPC3 were found in seven (16%) members of two (20%) families. Two (5%) patients showed double heterozygosis for both genes. The mutations affected different domains of encoded proteins and led to variable phenotypic expression. A family history of HCM was identified in all genotype-positive individuals. Conclusions: In this first genetic-molecular analysis carried out in the south of Brazil, we found mutations in the sarcomeric genes MYH7 and MYBPC3 in 58% of individuals. MYH7-related disease was identified in the majority of cases with mutation. Fundamento: Mutações em genes do sarcômero são encontradas em 60-70% dos indivíduos com formas familiares de cardiomiopatia hipertrófica. (CMH). Entretanto, essa estimativa refere-se a populações de países do hemisfério norte. O perfil genético-molecular da CMH foi tema de poucos estudos no Brasil, particularmente na região sul do país. Objetivo: Realizar a pesquisa de mutações dos genes sarcoméricos MYH7, MYBPC3 e TNNT2 numa coorte de CMH estabelecida no extremo sul do Brasil, assim como avaliar as associações genótipo-fenótipo. Métodos: Sequenciamento direto do DNA de todas as regiões codificantes dos três genes sarcoméricos foi realizada em 43 indivíduos consecutivos de dez famílias não-relacionadas. Resultados: Mutações para CMH foram encontradas em 25 (58%) indivíduos de sete (70%) das dez famílias estudadas, sendo 14 (56%) deles fenótipo-positivos. Todas as mutações eram missense, quatro (66%) no gene MYH7 e duas (33%) no gene MYBPC3. Não foram encontradas mutações no gene TNNT2. Mutações em MYH7 foram identificadas em 20 (47%) indivíduos de seis (60%) famílias. Duas delas não haviam sido previamente relatadas. Mutações de MYBPC3 foram detectadas em sete (16%) membros de duas (20%) famílias. Dois (5%) indivíduos apresentaram dupla heterozigose com mutações em ambos os genes. As mutações acometeram distintos domínios das proteínas codificadas e produziram expressão fenotípica variável. História familiar de CMH foi identificada em todos os indivíduos genótipo-positivos. Conclusões: Nessa primeira análise genético-molecular da CMH realizada no sul do Brasil, foram encontradas mutações nos genes sarcoméricos MYH7 e MYBPC3 em 58% dos indivíduos. Doença relacionada ao gene MYH7 foi identificada na maioria dos casos com mutação.
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Affiliation(s)
- Beatriz Piva E Mattos
- Faculdade de Medicina - Universidade Federal do Rio Grande do Sul, Serviço de Cardiologia - Hospital de Clínicas de Porto Alegre, RS - Brazil
| | | | - Marco Antonio Rodrigues Torres
- Faculdade de Medicina - Universidade Federal do Rio Grande do Sul, Serviço de Cardiologia - Hospital de Clínicas de Porto Alegre, RS - Brazil
| | - Laura Simon
- Centro de Terapia Gênica - Hospital de Clínicas de Porto Alegre, RS - Brazil
| | | | - Roberto Giugliani
- Instituto de Biociências - Universidade Federal do Rio Grande do Sul, Serviço de Genética Médica - Hospital de Clínicas de Porto Alegre, RS - Brazil
| | - Úrsula Matte
- Instituto de Biociências - Universidade Federal do Rio Grande do Sul, Unidade de Análise de Moléculas e Proteínas - Hospital de Clínicas de Porto Alegre, RS - Brazil
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Barefield DY, Lynch TL, Jagadeesan A, Sanagala T, Sadayappan S. High-Throughput Diagnostic Assay for a Highly Prevalent Cardiomyopathy-Associated MYBPC3 Variant. ACTA ACUST UNITED AC 2016; 7. [PMID: 27990320 PMCID: PMC5160998 DOI: 10.4172/2155-9929.1000303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 25-basepair deletion variant of MYBPC3 occurs at high frequency in individuals of South Asian descent and is estimated to affect 55 million people worldwide, carrying an increased likelihood of cardiomyopathy. Since this variant is prevalent and severe in this subpopulation, quick and affordable screening to provide risk-assessment to guide treatment for these patients is critical. An RNaseH qPCR assay was developed to quickly and specifically diagnose the presence of the 25-basepair deletion variant in MYBPC3. RNAseH-blocked nucleotide primers were designed to identify the presence or absence of the wild type MYBPC3 allele or the genomic sequence containing the 25-basepair deletion. Using this assay, three blinded operators were able to accurately determine the genotype from human genomic DNA samples from blood and saliva using a qPCR thermocycler. Furthermore, positive variant subjects were examined by both electrocardiography and echocardiography for the presence of cardiomyopathy. A simple, robust assay was established, verified and validated that can be automated to detect the presence of the highly prevalent 25-basepair deletion MYBPC3 variant using both blood and saliva samples. The assay will provide quick and accurate prescreening of individuals at high risk for cardiomyopathies and allow for better clinical identification of 25-basepair deletion MYBPC3 carriers in large cohort epidemiological studies.
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Affiliation(s)
- David Y Barefield
- Department of Cell and Molecular Physiology, Loyola University, Chicago, USA; Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Thomas L Lynch
- Department of Cell and Molecular Physiology, Loyola University, Chicago, USA
| | | | - Thriveni Sanagala
- Department of Cardiology and Echocardiography and Cardiographics, Loyola University, Chicago, USA
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Maron BJ, Spirito P. Surgical Ventricular Septal Myectomy in the Developing World. Am J Cardiol 2016; 117:874-7. [PMID: 26796193 DOI: 10.1016/j.amjcard.2015.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/03/2015] [Accepted: 12/03/2015] [Indexed: 10/22/2022]
Abstract
Surgical septal myectomy is the preferred treatment strategy in hypertrophic cardiomyopathy (HC) to reverse progressive heart failure symptoms due to left ventricular outflow obstruction. However, open-heart surgery and the ventricular septal myectomy option in particular have limited accessibility in many parts of the world, including developing countries such as India, where skilled surgeons familiar with the complex left ventricular outflow tract anatomy of obstructive HC are rare. Indeed, septal myectomy, which is currently performed in only a limited number of countries, can become available in other venues if experienced surgeons dedicate their skills to this highly specialized but rewarding operation. Relevant to this issue, we describe a recent myectomy initiative in India (New Delhi) that demonstrates the possibility of generating a surgical myectomy program outside of an elite academic center environment, otherwise regarded as unfavorable for such an initiative. Demonstration that safe and effective septal myectomy is possible under such difficult circumstances bodes well for the expansion of this operation to many countries in the best interests of the hypertrophic cardiomyopathy patient population.
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Contemporary strategies for risk stratification and prevention of sudden death with the implantable defibrillator in hypertrophic cardiomyopathy. Heart Rhythm 2016; 13:1155-1165. [PMID: 26749314 DOI: 10.1016/j.hrthm.2015.12.048] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Indexed: 12/29/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is regarded as the most common nontraumatic cause of sudden death (SD) in young people (including trained athletes). Introduction of implantable cardioverter-defibrillators (ICD) to HCM 15 years ago represented a new paradigm for clinical practice and probably the most significant advance in management of this disease. ICDs offer protection against SD by terminating potentially lethal ventricular tachyarrhythmias (11%/year secondary and 4%/year primary prevention), although implant decisions are weighed against the possibility of device-related complications (5%/year). ICDs have altered the natural history of HCM, creating the opportunity for extended or normal longevity for many patients. However, assessing SD risk and targeting appropriate candidates for prophylactic device therapy can be compounded by unpredictability of the underlying arrhythmogenic substrate, evident by delays ≥10 years between implant and first ICD intervention. Multiple or a single strong risk marker within the clinical profile of an individual HCM patient can justify consideration for a primary-prevention ICD when combined with physician judgment and shared decision making. The role of the mathematical SD risk score proposed by the European Society of Cardiology to identify patients who benefit from ICD therapy is incompletely resolved. Contemporary treatment interventions and advanced risk stratification using ≥1 conventional markers have served the HCM patient population well, with reduced disease-related mortality rates across all age groups to <1%/year, due largely to the penetration of ICDs into HCM practice. Prevention of SD has now become an integral, albeit challenging, component of HCM management, contributing importantly to its emergence as a contemporary treatable cardiac disease.
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Importance and feasibility of creating hypertrophic cardiomyopathy centers in developing countries: the experience in India. Am J Cardiol 2015; 116:332-4. [PMID: 25983127 DOI: 10.1016/j.amjcard.2015.04.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 11/24/2022]
Abstract
Hypertrophic cardiomyopathy (HC) is a relatively common genetic heart disease responsible for mortality and morbidity at all ages. Using contemporary treatment advances, such as implantable defibrillators, surgical myectomy, heart transplant, and modern defibrillation for out-of-hospital cardiac arrest, it is now possible to reduce HC-related mortality considerably to 0.5% per year, less than expected in the general US adult population. However, in much of the developing world, HC has not yet become a priority given the many other cardiac conditions, such as coronary artery disease and systemic hypertension, so prevalent in the most populous countries such as China and India. Management of HC is best achieved in dedicated centers within institutions, such as previously demonstrated in the United States, Canada, some European countries, and Australia. This model has recently been introduced for the first time in India at the Amrita Institute of Medical Sciences and Research in Kochi, Kerala, in which a robust program focused on HC has emerged. This novel initiative, created despite the many obstacles in the Indian health care system, is an important step forward and is reported here detail.
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