[Hypertrophic cardiomyopathy. Long-term clinical development in a regional cohort of 243 patients]

This retrospective study was undertaken to assess the long-term clinical outcome of hypertrophic cardiomyopathy (HCM) in a regional cohort of 243 patients aged 40.4 years on average at the time of diagnosis and followed up for 12.3 +/- 8.1 years. Forty-one deaths were recorded during the follow-up period directly related to HCM (including 20 sudden deaths and 17 deaths due to cardiac failure), an annual cardiac mortality rate of 1.37%. In multivariate analysis, two factors were associated with extra mortality: occurrence of the first symptoms before the age of 20 (RR x 2.35) (p = 0.006) and NYHA functional classes III: IV at the latest clinical assessment (p = 0.005). The risk of sudden death increased significantly with septal wall thickness: RR x 2.34 (p = 0.05), RR x 3.27 (p = 0.007) and RR x 3.67 (p = 0.02) respectively, for septal thickness equal to or greater than 25, 30 and 35 mm. Eighty-three patients (34%) had major cardiovascular events (sudden death, congestive cardiac failure, cerebrovascular accident) during follow-up. However, at the latest clinical assessment, 79% were relatively unaffected by their disease, without treatment (12%) or with drug therapy alone (60%). In a minority of patients (28%) a more aggressive therapeutic approach was necessary: cardiac pacing (N = 48), implantable cardiac defibrillators (N = 2) myomectomy (N = 27) or cardiac transplantation (N = 6). The authors conclude that HCM is a complex disease, less serious than initially thought in the majority of patients, but the cause of major cardiovascular events and premature deaths which still remain difficult to prevent.