Clinical Characteristics and Long-Term Outcomes of Hypertrophic Cardiomyopathy

Results from the Aichi Hypertrophic Cardiomyopathy (AHC) Registry

Abstract

Hypertrophic cardiomyopathy (HCM) has various morphological and clinical features. A decade has passed since the previous survey of the epidemiological and clinical characteristics of Japanese HCM patients. The Aichi Hypertrophic Cardiomyopathy (AHC) Registry is based on a prospective multicenter observational study of HCM patients. The clinical characteristics of 42 ambulant HCM patients followed up for up to 5 years were investigated. The primary endpoint was major adverse cardiac events (MACE), defined as death, non-fatal stroke, admission due to congestive heart failure (CHF), or episodes of sustained ventricular tachycardia/fibrillation. The MACE-free survival during the 5-year follow-up period was 76% according to Kaplan–Meier analysis. HCM-related death occurred in 3 (7%) patients and SCD occurred in 2 (5%) patients. Additionally, 3 (7%) patients were admitted to the hospital due to CHF. Meanwhile, sustained VT was detected in one (2%) of the patients who received ICD implantation and subsequently terminated with antitachycardia pacing using an ICD. The patients with HCM exhibiting left ventricular outflow obstruction (HOCM) had a slightly lower MACE-free survival rate than those with neither HOCM nor dilated-HCM (dHCM) (71% versus 81%, log-rank P = 0.581). Furthermore, the patients with dHCM demonstrated a significantly lower MACE-free survival rate than those with neither HOCM nor dHCM (33% versus 81%, log-rank P = 0.029). In the AHC Registry targeting current Japanese HCM patients, we demonstrated that many HCM patients continue to suffer from MACE despite the development of various treatments for HCM.