The clinical features, outcomes and genetic characteristics of hypertrophic cardiomyopathy patients with severe right ventricular hypertrophy

Abstract

IntroductionSevere right ventricular hypertrophy (SRVH) is a rare phenotype in hypertrophic cardiomyopathy (HCM) for which limited information is available. This study was undertaken to investigate the clinical, prognostic and genetic characteristics of HCM patients with SRVH.MethodsHCM with SRVH was defined as HCM with a maximum right ventricular wall thickness ≥10 mm. Whole-genome sequencing (WGS) was performed in HCM patients with SRVH. Multivariate Cox proportional hazards regression models were used to identify risk factors for cardiac death and events in HCM with SRVH. Patients with apical hypertrophic cardiomyopathy (ApHCM) were selected as a comparison group. The clinical features and outcomes of 34 HCM patients with SRVH and 273 ApHCM patients were compared.ResultsCompared with the ApHCM group, the HCM with SRVH group included younger patients and a higher proportion of female patients and also displayed higher cardiovascular morbidity and mortality. The multivariate Cox proportional hazards regression models identified 2 independent predictors of cardiovascular death in HCM patients with SRVH, a New York Heart Association class ≥III (hazard ratio [HR] = 8.7, 95% confidence interval (CI): 1.43-52.87, p = 0.019) and an age at the time of HCM diagnosis ≤18 (HR = 5.5, 95% CI: 1.24-28.36, p = 0.026). Among the 11 HCM patients with SRVH who underwent WGS, 10 (90.9%) were identified as carriers of at least one specific sarcomere gene mutation. MYH7 and TTN mutations were the most common sarcomere mutations noted in this study. Two or more HCM-related gene mutations were observed in 9 (82%) patients, and mutations in either other cardiomyopathy-related genes or ion-channel disease-related genes were found in 8 (73%) patients.ConclusionsHCM patients with SRVH were characterized by poor clinical outcomes and the presentation of multiple gene mutations.

Phenotypic diversity identified by cardiac magnetic resonance in a large hypertrophic cardiomyopathy family with a single MYH7 mutation

“…III4 experienced sudden death18 months after surgical septal myectomy and II5 was recommended to have an ICD implantation. Third, previous works showed that areas of focal fibrosis identified by LGE was associated with prognosis in HCM 22 , diffuse fibrosis detected by ECV had significant association to fibrosis measured histologically 23–25 , and different morphological subtype of hypertrophic cardiomyopathy could have diverse prognosis 26–28 . In the present study, the 8 HCM phenotypically positive and 1 borderline affected individuals had variable morphological subtypes, focal fibrosis by LGE, and diffuse fibrosis by ECV, which provided strong evidence for variable phenotypes associated with the same genotype.…”

Prevalence, functional characteristics, and clinical significance of right ventricular involvement in patients with hypertrophic cardiomyopathy

“…In an early study, using transthoracic echocardiography, RV hypertrophy was reported in 44% of patients with HCM 10 . Studies using CMR demonstrated a prevalence ranging from 1.3 to 30%, depending on the criteria of RV involvement 4 , 5 , 11 . Our study showed a prevalence of 14.4%, with the RVMWT ≥ 7 mm on CMR.…”

Severe right ventricular hypertrophy in hypertrophic cardiomyopathy: Serious symptoms, complex surgical procedures, and poor prognosis in Fuwai Hospital

“…It is now widely accepted that HCM is a disease involving both cardiac ventricles rather than being morphologically limited to the left ventricle. The incidence of RV hypertrophy in patients with HCM is 30%-53% as shown by CMR imaging and echocardiography studies (6,7,9,11), whereas SRVH is relatively uncommon (prevalence of 1.3%) (12). In our study, among the 1,316 patients with HCM who underwent LGE CMR imaging Previous studies have identified a significant correlation between the maximum RV and LV wall thickness (7).…”