Usefulness of Left Atrial Volume as an Independent Predictor of Development of Heart Failure in Patients With Atrial Fibrillation.

Left atrial (LA) volume is known as a robust predictor of heart failure (HF) development in patients with sinus rhythm. However, among patients with atrial fibrillation (AF), the utility of LA volume for prediction of HF development has not been determined. The objective of this study was to investigate the utility of LA volume for prediction of HF development in patients with AF. Among adult patients who were referred for transthoracic echocardiography, those with AF at the baseline echocardiography were included and prospectively followed up to new-onset HF events. Patients who had significant valvular heart disease, congenital heart disease, or reduced left ventricular (LV) ejection fraction were excluded. Cox-proportional hazards models were used to assess the risk of HF development. Of a total of 562 patients, 422 (mean age 69.6 ± 9.7 years, 66.1% men) met study criteria, and 52 (12.3%) developed HF during a mean follow-up of 55 ± 43 months. Patients with HF events had larger indexed LA volume, compared with those without HF events (69 ± 46 vs 50 ± 23 ml/m2, p <0.0001). In a multivariable analysis adjusted for other co-morbidities, LA volume was a significant predictor for HF development [per 10 ml/m2; hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.06 to 1.22, p <0.001], independently of age (per 10 years; HR 1.71, 95% CI 1.16 to 2.52, p <0.01), LV ejection fraction (per 10%; HR 0.67, 95% CI 0.52 to 0.86, p <0.01), and indexed LV mass (per 10 g/m2; HR 1.13, 95% CI 1.03 to 1.24, p <0.05). Also, LA volume had an incremental effect for prediction of HF development to these conventional risk factors (p <0.0001). In conclusion, LA volume provides prognostic information for the prediction of future HF events in patients with AF.