E/e' ratio is a strong prognostic predictor of mortality in patients with non-valvular atrial fibrillation with preserved left ventricular systolic function

Background: The purpose of this study was to investigate the prognostic values of the E/e' ratio and other echocardiographic and clinical parameters in patients with non-valvular atrial fibrillation (AF) with preserved left ventricular (LV) systolic function. Methods and Results: A total of 488 patients (322 men, age: 66±11 years) with non-valvular AF with preserved LV systolic function (LV ejection fraction >50%) were included. The E and e' velocities were measured in 5 consecutive heart beats and averaged. Mean follow-up duration after enrollment was 17.7±5.3 months. All-cause deaths occurred in 45 patients (cardiovascular deaths: n=29). There were significant differences in age (65.6±11.3 vs. 71.5±9.1, P<0.001) and hemoglobin concentration (13.6±2.9 vs. 11.5±3.4 g/dl, P<0.0001) between the deceased group and the survivors. E/e' ratio in the deceased group was significantly higher than that in the survivors (17.67±3.39 vs. 10.8±3.30, P<0.001). Survival analysis showed that a high E/e' ratio (>15.0) represents a poorer prognosis (P<0.001 by Log-Rank test) than an E/e' ratio of 15 and below. Multivariate analysis identified 2 significant variables that were predictive of all-cause deaths: hemoglobin (hazard ratio (HR)=0.806, 95% confidence interval (CI)=0.733-0.886, P<0.0001), and E/e' >15 (HR=3.064, 95%CI=1.38-6.804, P=0.006). Conclusions: E/e' ratio is a useful independent prognostic parameter for predicting mortality in patients with AF with preserved LV systolic function.