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


METHODS
HCM 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.


RESULTS
Compared 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.


CONCLUSIONS
HCM patients with SRVH were characterized by poor clinical outcomes and the presentation of multiple gene mutations.
Key Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Xiying
X
Guo
Key Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Chaomei
C
Fan
Key Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Lei
L
Tian
Department of Ultrasound, Fuwai Hospital, Beijing, China.
Yanling
Y
Liu
Department of Pathology, Fuwai Hospital, Beijing, China.
Hongyue
H
Wang
Department of Radiology, Fuwai Hospital, Beijing, China.
Shihua
S
Zhao
Department of Ultrasound, Fuwai Hospital, Beijing, China.
Fujian
F
Duan
Department of Cardiology, Anqiu Chinese Medicine Hospital, Anqiu, China.
Xiuling
X
Zhang
Department of Cardiology, Heze Zone Central Hospital, Heze, China.
Xing
X
Zhao
Department of Cardiology, Zhecheng People's Hospital, Zhecheng, China.
Fengqi
F
Wang
Department of Cardiology, The Harbor Hospital of Yantai, Yantai, China.
Hongguang
H
Zhu
Department of Cardiology, Muping District Chinese Medicine Hospital of Yantai, Yantai, China.
Aiqing
A
Lin
Department of Cardiology, Laiwu Central Hospital, Laiwu, China.
Xia
X
Wu
Key Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Yishi
Y
Li
D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D004452:Echocardiography; D005260:Female; D020022:Genetic Predisposition to Disease; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D017380:Hypertrophy, Right Ventricular / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome