Abstract 12673: How Low is Low Risk in Hypertrophic Cardiomyopathy? Sudden Death in Patients Without Conventional Risk Factors
Background: In recent years, research has focused on the identification of patients with hypertrophic cardiomyopathy (HCM) at high risk for sudden death who could be potential candidates for the implantable cardioverter-defibrillator (ICD). While the ICD has been life-saving for many such patients, the outcome of those patients without conventional risk factors who are judged to be at low risk for sudden death, remains unresolved.
Methods: We assessed the risk for sudden death in a consecutive cohort of 721 HCM patients without any of the major conventional risk factors, including family history of sudden death, extreme LV hypertrophy (maximal wall thickness ≥ 30 mm), non-sustained ventricular tachycardia on Holter monitoring, and unexplained syncope.
Results: In this study cohort, mean age was 43 years (median 45). Over a median follow-up of 5.1 years, 22 patients (3.1%) died suddenly, for a sudden death incidence of 0.5% per year. Mean age at time of sudden death was 48 years, with 14 patients (64%) < 50 and 7 (32%) < 35. Left ventricular outflow obstruction under basal conditions was present in 6 patients (27%), mean LV wall thickness was 21 mm (range 14 to 27 mm) and left atrial size 45 mm (range 37 to 67 mm).
Conclusions: In this large HCM cohort regarded to be at low risk for sudden death based on generally accepted risk stratification criteria, the absence of conventional risk factors did not guarantee immunity from sudden death, suggesting the need for additional risk markers in this disease.
- © 2011 by American Heart Association, Inc.