Risk of sudden death in end-stage hypertrophic cardiomyopathy

Background: It remains unclear whether end-stage hypertrophic cardiomyopathy (HCM) is associated with as high a rate of sudden death as occurs among HCM patients with preserved left ventricular (LV) systolic function. The purpose of this study was to evaluate the incidence of sudden death among patients with end-stage HCM and to identify high-risk end-stage patients.

Methods and results: A total of 490 consecutive patients with HCM, who were diagnosed and followed-up at our hospital, were analyzed retrospectively. End-stage HCM was defined by an LV ejection fraction <50% on echocardiography during follow-up. Among the 490 HCM patients, 43 patients (8.8%) were diagnosed as having end-stage HCM during a mean follow-up period of 12 ± 7 years after the initial diagnosis. During a mean follow-up period of 5 ± 3 years after progression to end-stage HCM, sudden death occurred in 21 of 43 patients (47%). Cox proportional hazards analysis identified syncope as an independent predictor of sudden death (hazard ratio = 6.15; 95% confidence interval, 2.40-15.75; P < .001).

Conclusions: This study demonstrated that patients with end-stage HCM have a high incidence of sudden death. Therefore, it is suggested that an aggressive therapeutic strategy to counter sudden death should be considered for patients with end-stage HCM.