Two Hundred Eight Patients With Apical Hypertrophic Cardiomyopathy in China: Clinical Feature, Prognosis, and Comparison of Pure and Mixed Forms

BACKGROUND: Apical hypertrophic cardiomyopathy (AHCM) is a relatively rare form of hypertrophic cardiomyopathy (HCM), originally described in Japan and later in the West. Limited information is available on this disease in China. HYPOTHESIS: This study was designed to describe clinical features and prognoses of patients with AHCM in China. METHODS: A retrospective study of 208 consecutive patients with AHCM examined at FuWai Hospital was performed. Clinical features, mortality, and cardiovascular morbidity were analyzed. RESULTS: The 208 patients with AHCM represented 16.0% of all HCM patients. Among them, 64.4% were pure form and 35.6% were mixed form. Compared with the pure group, the mixed group had a significantly larger left atrial diameter and thicker apical thickness. One hundred ninety-nine patients had a mean follow-up of 8.0 ± 3.5 years, cardiovascular mortality was 1.0%, and annual cardiovascular mortality was 0.1%. The 2 cardiovascular deaths were both mixed form. The probability of survival was 97.0 ± 2% at 10 years. Of the patients, 17.8% had 1 or more cardiovascular events. The probability of survival without morbid events at 10 years was 77 ± 4%. Three independent predictors of cardiovascular morbidity were identified: age at diagnosis ≥60 years, left atrial diameter ≥36 mm, and New York Heart Association class ≥III at baseline. CONCLUSIONS: The prevalence of AHCM is relatively high, and it has a benign prognosis in China. However, 17.8% of patients may develop cardiovascular events. It is important to distinguish the 2 phenotypes of AHCM; the mixed form is less common but more serious than the pure form.