Differences in Characteristics and Outcomes Between Patients With Hypertrophic Cardiomyopathy From Asian and European Centers

Hypertrophic cardiomyopathy (HCM) is a common form of inherited cardiomyopathy with a prevalence in the general population reported as 0.2% in different international studies.1 Although differences in disease expression and outcome are described among White and Black patients with HCM,2 it is largely unknown whether Asian patients present also a different HCM phenotype. Only 1 study included 133 Asian patients and highlighted health disparities among ethnicities relating to access to genetic testing and implantable cardioverterdefibrillator (ICDs) use.3 In our study, a total of 1661 consecutive patients (1210 European patients; 451 Asian patients including 308 Chinese, 83 Malay, and 60 South Asian patients) diagnosed with HCM according to current criteria1 were included from 3 centers (Leiden University Medical Center, The Netherlands; National University Hospital, Singapore; Aristoteleio University of Thessaloniki, Greece). This study aimed to evaluate the differences between patients with HCM from the European centers (n=1214, 1% Asian ethnicities) and the Asian center (n=447, 97% Asian ethnicities), to elucidate the influence of ethnicity, differences in care patterns, and sociocultural factors on patient outcome. The institutional review boards approved this retrospective analysis and waived the need for informed consent. The data that support the findings of this study are available from the corresponding author upon reasonable request. At the time of diagnosis, patients from the Asian center were older than those from the European centers (59 [47– 68] years versus 52 [41– 62] years, P<0.001), with similar proportion of men (71% versus 67%, P=0.093) and lower body surface area (1.7±0.2 m2 versus 2.0±0.2 m2, P<0.001). Diabetes (22% versus 16%, P=0.004) was more frequent in European centers, whereas hypertension (23% versus 49%, P<0.001) and coronary artery disease (8% versus 28%, P<0.001) were more prevalent in the Asian center. New York Heart Association functional class (class III– IV 7% versus 10%, P=0.096) at presentation was not significantly different between patients from Asian and European centers. By echocardiography, patients from the Asian center presented with smaller septal wall thickness (16 [13– 19] mm versus 18 [16– 22] mm, P<0.001) but the maximum wall thickness (19 [17– 22] mm versus 19 [16– 22] mm,