Abstract 15191: Left Atrial Volume as an Independent Predictor of Congestive Heart Failure in Patients With Atrial Fibrillation

Abstract

Backgound: Left atrial (LA) enlargement has been proposed as a barometer of diastolic dysfunction and a predictor of congestive heart failure (CHF) in patients with sinus rhythm. Whether LA volume predicts CHF in patients with atrial fibrillation (AF) is not well known. Methods: To determine the clinical importance of LA volume in the prediction of CHF in patients with AF, AF patients referred for clinically-indicated echocardiogram, without a history of significant mitral valve disease, congenital heart disease, pacemaker, or cardiac surgery, in 2007-2008 were prospectively included and followed forward them up to September 2014. LA volume was measured using the biplane area-length formula. CHF was ascertained using the Framingham criteria. Cox proportional hazards modeling was used to assess the risk factors of CHF development. Results: Of 456 AF patients who met all study criteria (mean 70 ± 10 year-old, 67% men, 62% hypertension, 26% diabetes, LV ejection fraction 68 ± 13%, LA volume 52 ± 24 mL/m 2 ), 46 (10%) developed CHF events during a mean follow-up of 44 ± 31 months. CHF events were significantly increased with advancing age (HR 1.4, 95%CI 1.0-2.0, P<0.05), but not with sex. In a multivariate Cox proportional hazards model, greater indexed LA volume (per 10 mL/m 2 ; HR 1.2, 95% CI 1.1-1.3, P<0.01) was independent of age (HR 1.04, 95% CI 1.01-1.07, P=0.03), sex (P=0.77), history of CHF (P=0.58), hypertension (P=0.38), diabetes (P=0.89), and LV ejection fraction (HR 0.95, 95% CI 0.93-0.96, P<0.001) for the prediction of CHF development. The Kaplan-Meier estimate of cumulative CHF-free survival by indexed LA volume was shown (Fig.). Conclusions: In our cohort with AF, LA volume predicted CHF developments, independent of LV systolic function and other cardiovascular comorbidities, which appears to be clinically useful information for risk stratification.