Very long‐term prognosis in patients with hypertrophic cardiomyopathy: a longitudinal study with a period of 20 years

AIMS: We aim to clarify the prognosis on patients with hypertrophic cardiomyopathy (HCM) for a follow‐up period of more than 10 years. METHODS AND RESULTS: We retrospectively analysed 102 consecutive patients with HCM diagnosed by 31 December 2000. Complete and detailed clinical records were obtained for 93 (91%) of the 102 patients. Sixty‐three (68%) of the 93 patients were men, and the mean age of the patients at the initial evaluation was 51.5 ± 13.0 years. During the mean follow‐up period of 19.6 ± 8.1 years (median 20.1 years), HCM‐related deaths occurred in 20 patients (21% [1.1%/year]). HCM‐related adverse events (including HCM‐related deaths and nonfatal HCM‐related events: hospitalization for heart failure, embolic stroke admission, and sustained ventricular tachycardia with haemodynamic instability or appropriate implantable cardioverter‐defibrillator discharge) occurred in 45 patients (48%). The first HCM‐related adverse events occurred in approximately 20% of the patients in every decade, the first decade to the third decade, from the initial evaluation. Forty‐seven patients (51%) had documentation of atrial fibrillation at the last follow‐up. There were seven patients in the end‐stage HCM group at the initial evaluation, and 22 patients (24%) had progression to end‐stage HCM during the follow‐up period. CONCLUSIONS: In our cohort of patients, HCM‐related mortality was relatively favourable. However, approximately half of the patients suffered from HCM‐related adverse events during the follow‐up period of 20 years. It is important for HCM patients to be carefully followed up over the long‐term because HCM is a lifelong disease.