Abstract 11314: Atrial Fibrillation in Hypertrophic Cardiomyopathy: Epidemiology and Risk of Death
Background: Atrial fibrillation (AF) is a common sequela of hypertrophic cardiomyopathy (HCM). Herein we sought to evaluate the prevalence of atrial fibrillation in a large referral HCM population, identify potential risk factors for AF, and assess its effect on survival.
Methods: 3,673 adult patients with HCM underwent index visit at our institution between January 1975 and September 2012. Presence of AF was defined by known history (either chronic or paroxysmal) or electrocardiogram at first visit. Kaplan Meier survival curves were assessed via log-rank test. The effect of AF on mortality was examined with univariate and age-adjusted Cox proportional hazards models.
Results: 650 patients (18%) had AF. Compared to non-AF patients, AF patients were older (60±14 vs. 54±16 years, p<0.001) and more likely to exhibit NYHA class III-IV symptoms (46 vs. 39%, p=0.002), had higher BNP (440±469 vs. 255±302 pg/mL, p<0.001, n=763), were less likely to have obstructive physiology (68 vs. 76%, p<0.001), had larger left atria (volume index 62±38 vs. 45±16 cm3/m3, p<0.001, n=1,706), higher E/e’ ratio (19±9 vs. 17±8, p<0.001, n=1,649) and worse cardiopulmonary exercise tolerance (peak VO2 17±6 vs. 21±7 mL/kg/min, p<0.001; percent VO2 predicted 60±20 vs. 65±19%, p<0.001; n=1,272). During a follow-up of 4.9 ± 6.6 years, 974 patients died. Patients with AF had worse survival compared to non-AF patients (p<0.001, Figure). The univariate and age-adjusted risk ratios and 95% confidence intervals for AF on mortality were 1.58 (1.35-1.85) and 1.38 (1.18-1.61), respectively. AF was independently associated with mortality in multivariate analysis.
Conclusions: In this large HCM population, approximately 1 in 5 patients had AF. Patients with AF were more symptomatic and had worse cardiopulmonary exercise tolerance. AF is a strong predictor of mortality in HCM, even after adjustment for other risk factors.
- © 2013 by American Heart Association, Inc.