Abstract 16136: Left Atrial Size is Superior to Left Ventricular Ejection Fraction in Predicting Mortality Among Patients With Atrial Fibrillation

IntroductionLeft atrial (LA) enlargement is highly prevalent in patients with atrial fibrillation (AF). The association between LA size, left ventricular function and the risk of death among patients with AF remains largely unexplored.PurposeWe sought to evaluate the prognostic value of LA size as a predictive tool for death among hospitalized patients with AF.MethodsLA volume and left ventricular ejection fraction (LVEF) were measured by transthoracic echocardiography. LA volume was indexed to the body surface area to derive the LA volume index (LAVi). LA size was defined as normal (LAVi 16-28 mL/m), mildly enlarged (LAVi 29-33 mL/m), moderately enlarged (LAVi 34-39 mL/m) and severely enlarged (LAVi >40 mL/m). The outcome measure was all-cause mortality.ResultsIn total, 1135 hospitalized patients with AF were reviewed (mean age 75.5±9.0 years, mean CHA2DS2-VASc score 4.5±2.1). Over a median follow-up of 2 years, 346 (30.5%) patients died. Enlarged LA was present in 930 (82%) patients. Unadjusted survival analysis showed that LA enlargement was associated with a 2-fold increased risk of death (HR 1.92 95% CI 1.43-2.68). Kaplan-Meier survival analysis illustrated a progressive increase in the mortality rates by the severity of the LA enlargement (Figure 1). After adjustment in multivariate Cox proportional hazard analysis, strong association was observed between mortality and both LAVi (HR 1.05 per 1mL/m increase, 95% CI 1.04-1.06, p