Comparison of Apical and Asymmetric Septal Phenotype in Patients With Hypertrophic Cardiomyopathy: Clinical Features and Prognosis / 中国循环杂志

ABSTRACT

Objectives: To compare the clinical features and long-term outcomes of patients with apical hypertrophic cardiomyopathy (ApHCM) and patients with asymmetric septal hypertrophic cardiomyopathy (ASHCM). Methods: Data from 600 patients (300 with ApHCM and 300 with ASHCM) identified in a consecutive single-center cohort between 1996 and 2014 were retrospectively analyzed. The two groups were 11 matched by age of diagnosis, gender and the presence of outflow tract obstruction. Clinical features, cardiovascular mortalities, incidence of sudden cardiac death and cardiovascular morbidity (including unexplained syncope, atrial fibrillation, nonsustained ventricular tachycardia, progressive heart failure, embolic stroke or transient ischemic attack and myocardial infarction) were compared between the two groups. Results: Forty-two patients (14.0%) had a maximum LV wall thickness of ≥30 mm in the ASHCM group compared to only 11 patients (3.7%) in the ApHCM group (P<0.01). 156 patients in ApHCM group (52.0%)and 168 patients in ASHCM group(56.0%)underwent cardiovascular NMR examination, the incidence of late gadolinium enhancement was significantly lower in ApHCM group than in ASHCM group(26.9% vs 76.2%,P<0.01). The mean follow-up durations for ApHCM and ASHCM were (7.5 ± 4.0) years and (6.6 ± 5.4) years, respectively. The incidence of cardiovascular death (1.0% vs 5.7%), sudden cardiac death (0.33% vs 3.3%) and major adverse cardiovascular event (18.3% vs 40.3%) were significantly lower in the ApHCM group than in the ASHCM group (all P<0.01). Unexplained syncope, nonsustained ventricular tachycardia, and progressive heart failure were less common in ApHCM group than in ASHCM group (all P<0.05). Multivariate COX regression analysis showed that late gadolinium enhancement positivity (HR=4.62, 95% CI 2.28- 68.0, P=0.02) and unexplained syncope (HR=8.56, 95% CI 2.1-16.6, P<0.01) were independent predictors of cardiovascular mortality. Unexplained syncope was independent predictor for sudden cardiac death (HR=4.40, 95% CI 1.5-15.2, P=0.02). Conclusions: After eliminating the interference of age at diagnosis, gender and outflow tract obstruction, patients with ApHCM represent a more benign prognosis with a lower incidence of cardiovascular mortality and morbidity than patients with ASHCM.