Left Atrial Function Predicts Heart Failure Hospitalization in Subjects With Preserved Ejection Fraction and Coronary Heart Disease

Objectives We 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 of LAFI: Q1: 47 per 1000 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 HR: 2.6, 95% CI 2.1–3.3, p<0.001), and the association persisted even after adjustment for clinical risk factors, NT-proBNP, and a wide range of echocardiographic parameters (adjusted HR: 1.5, 95% CI 1.0–2.1, p=0.05). Conclusions LA dysfunction independently predicts HF hospitalization in subjects with coronary heart disease and preserved baseline EF. LAFI may be useful for HF risk stratification, and LA dysfunction may be a potential therapeutic target.