Left atrial function predicts heart failure hospitalization in subjects with preserved ejection fraction and coronary heart disease: longitudinal data from the Heart and Soul Study.

Objectives: This study sought to determine whether left atrial (LA) dysfunction predicts heart failure (HF) hospitalization in subjects with preserved baseline ejection fraction (EF).
Background: Among patients with preserved EF, factors leading to HF are not fully understood. Cross-sectional studies have demonstrated LA dysfunction at the time of HF, but longitudinal data on antecedent atrial function are lacking.
Methods: We performed resting transthoracic echocardiography in 855 subjects with coronary heart disease and EF ≥50%. Left atrial functional index (LAFI) was calculated as ([LA emptying fraction × left ventricular outflow tract-velocity time integral] / [indexed LA end-systolic volume]), where LA emptying fraction was defined as (LA end-systolic volume--LA end-diastolic volume) / LA end-systolic volume. We used Cox models to evaluate the association between LAFI and HF hospitalization.
Results: Over a median follow-up of 7.9 years, 106 participants (12.4%) were hospitalized for HF. Rates of HF hospitalization were inversely proportional to quartile (Q) of LAFI: Q1, 47 per 1,000 person-years; Q2, 18.3; Q3, 9.6; and Q4, 5.3 (p < 0.001). Each standard deviation decrease in LAFI was associated with a 2.6-fold increased hazard of adverse cardiovascular outcomes (unadjusted hazard ratio: 2.6, 95% confidence interval: 2.1 to 3.3, p < 0.001), and the association persisted even after adjustment for clinical risk factors, N-terminal pro-B-type natriuretic peptide, and a wide range of echocardiographic parameters (adjusted hazard ratio: 1.5, 95% confidence interval: 1.0 to 2.1, p = 0.05).
Conclusions: Left atrial dysfunction independently predicts HF hospitalization in subjects with coronary heart disease and preserved baseline EF. The LAFI may be useful for HF risk stratification, and LA dysfunction may be a potential therapeutic target.
(Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)