Long-term outcome in patients with apical hypertrophic cardiomyopathy

Objectives The aim of this study was to describe long-term outcome in patients with apical hypertrophic cardiomyopathy (ApHCM) followed in a tertiary referral center. Background Apical hypertrophic cardiomyopathy is a relatively rare form of hypertrophic cardiomyopathy (HCM), first described in Japan. Initial reports, based on a limited number of patients, emphasized the benign nature of this condition. Methods A retrospective study of 105 patients with ApHCM diagnosed at the Toronto General Hospital from 1975 to 2000 was performed. Symptoms, clinical findings, mortality and cardiovascular morbidity were analyzed. Results The mean age at presentation was 41.4 ± 14.5 years. During a mean follow-up of 13.6 ± 8.3 years from presentation, cardiovascular mortality was 1.9% (2/105) and annual cardiovascular mortality was 0.1%. Overall survival was 95% at 15 years. Thirty-two patients (30%) had one or more major morbid events, the most frequent being atrial fibrillation (12%) and myocardial infarction (10%). Probability of survival without morbid events was 74% at 15 years. Three predictors of cardiovascular morbidity were identified: age at presentation <41 years, left atrial enlargement, and New York Heart Association (NYHA) class ≥II at baseline. Forty-four percent of the patients were asymptomatic at the time of last follow-up. Conclusions Apical hypertrophic cardiomyopathy in North American patients is not associated with sudden cardiac death and has a benign prognosis in terms of cardiovascular mortality. Nevertheless, one third of these patients experience serious cardiovascular complications, such as myocardial infarction and arrhythmias. These data are likely to influence the counseling and management of patients with ApHCM.