Clinical and echocardiographic predictors of outcomes in patients with apical hypertrophic cardiomyopathy

Abstract

Apical hypertrophic cardiomyopathy (HC) is considered to have a favorable prognosis, but recent observations have suggested less benign clinical courses. We investigated the outcomes in patients with apical HC and evaluated the predictors. All 454 patients with apical HC (316 men, age 61 ± 11 years) were recruited. Major cardiovascular events (MACE) were defined as unplanned hospitalization because of heart failure, stroke, or cardiovascular mortality. The patients were divided into 2 groups: group 1 with MACE and group 2 without MACE. During the follow-up period (43 ± 20 months), the all-cause mortality rate was 9% (39 of 454), and 110 patients (25%) had MACE. The subjects in group 1 were older and a greater proportion had diabetes, hypertension, and atrial fibrillation. On the echocardiogram, the left atrial volume index (left atrial volume index 36 ± 17 vs 31 ± 12 ml/m(2)), transmitral E velocity (65 ± 17 vs 61 ± 16 cm/s), mitral annulus Ea velocity (4.5 ± 1.4 vs 5.1 ± 1.8 cm/s), Sa velocity (5.8 ± 1.4 vs 6.6 ± 1.4 cm/s), E/Ea ratio (15 ± 5 vs 13 ± 5), and right ventricular systolic pressure (31 ± 8 vs 28 ± 7 mm Hg) were significantly different between groups 1 and 2 (p <0.05 for all). The left atrial volume index (for each 1-ml/m(2) increase, hazard ratio 1.01, 95% confidence interval 1.00 to 1.03; p = 0.047), Sa velocity (hazard ratio 0.83, 95% confidence interval 0.72 to 0.96, p = 0.014), and E/Ea ratio (hazard ratio 1.04, 95% confidence interval 1.00 to 1.09, p = 0.030) were independent predictors of a poor prognosis, along with age and the presence of diabetes or hypertension. In conclusion, the clinical outcomes of patients with apical HC were less benign in older patients and in those with hypertension or diabetes. In addition, the left atrial volume index, Sa velocity, and E/Ea ratio were predicters of a poor prognosis in patients with apical HC.