Epidemiology of hypertrophic cardiomyopathy-related death - Revisited in alarge non-referral-based patient population

Background-Death resulting from hypertrophic cardiomyopathy (HCM), particul arly when sudden, has been reported to be largely confined to young persons . These data emanated from tertiary HCM centers with highly selected referr al patterns skewed toward high risk patients. Methods and Results-The present analysis was undertaken in an international population of 744 consecutively enrolled and largely unselected patients m ore representative of the overall HCM spectrum. HCM-related death occurred in 86 patients (12%) over 8+/-7 years (mean+/-SD). Three distinctive modes of death were as follows: (1) sudden and unexpected (51%; age, 45+/-20 year s); (2) progressive heart failure (36%; age, 56+/-19 years); and (3) HCM-re lated stroke associated with atrial fibrillation (13%; age, 73+/-14 years). Sudden death was most common in young patients, whereas heart failure- and stroke-related deaths occurred more frequently in midlife and beyond. Howe ver, neither sudden nor heart failure-related death showed a statistically significant, disproportionate age distribution (P=0.06 and 0.5, respectivel y). Stroke related deaths did occur disproportionately in older patients (P =0.002). Of the 45 patients who died suddenly, most (71%) had no or mild sy mptoms, and 7 (16%) participated in moderate to severe physical activities at the time of death. Conclusions-HCM-related cardiovascular death occurred suddenly, or as a res ult of heart failure or stroke, largely during different phases of life in a prospectively assembled, regionally based, and predominantly unselected p atient cohort. Although most sudden deaths occurred in adolescents and youn g adults, such catastrophes were not confined to patients of these ages and extended to later phases of life. This revised clinical profile suggests t hat generally held epidemiological tenants for HCM have been influenced con siderably by skewed reporting from highly selected populations. These data are likely to importantly affect risk stratification and treatment strategi es importantly for the prevention of sudden death in HCM.