Prognostic Impact of Left Ventricular Apical Aneurysm Identified by Echocardiography in Hypertrophic Cardiomyopathy ― A Multicenter Retrospective Study in Japan ―

Background: This study evaluated the prognostic impact of left ventricular (LV) apical aneurysm identified by transthoracic echocardiography (TTE) in a Japanese cohort with hypertrophic cardiomyopathy (HCM). Methods and Results: We retrospectively enrolled 369 consecutive HCM patients from 2 centers (2016–2023). LV apical aneurysm was defined on TTE as a discrete, thin-walled dyskinetic/akinetic apical outpouching with a wide neck. Primary outcomes were all-cause death and cardiovascular (CV) death. Secondary outcomes were hospitalization for worsening heart failure, systemic embolism, sustained ventricular tachycardia (VT), and sudden cardiac death (SCD)-equivalent events (resuscitated cardiac arrest or appropriate implantable cardioverter defibrillator therapy). LV apical aneurysm was present in 47 of 369 patients (12.7%). There were no significant between-group differences in all-cause death (log-rank P=0.162) or CV death (P=0.103). Patients with LV apical aneurysm more frequently had baseline sustained VT and SCD-equivalent events; however, Kaplan–Meier analyses indicated no significant differences between groups in incident sustained VT and SCD-equivalent events after enrollment. In multivariable Cox models, age, B-type natriuretic peptide (BNP), and SCD-equivalent events were independently associated with all-cause death; BNP and SCD-equivalent events were independently associated with CV death. Conclusions: In this cohort, echocardiography-identified LV apical aneurysm was associated with a greater burden of baseline arrhythmic events, but not higher mortality. TTE provides a practical means of identifying this phenotype. BNP and SCD-equivalent events were more closely associated with mortality.