Association of the Ratio of Early Mitral Inflow Velocity to the Global Diastolic Strain Rate with a Rapid Renal Function Decline in Atrial Fibrillation

The ratio of early mitral inflow velocity (E) to the global diastolic strain rate (E'sr) has been correlated with left ventricular filling pressure and predicts adverse cardiac outcomes in atrial fibrillation (AF). The relationship between the E/E'sr ratio and renal outcomes in AF has not been evaluated. This study examined the ability of the E/E'sr ratio in predicting progression to the renal endpoint, which is defined as a >= 25% decline in the estimated glomerular filtration rate in patients with AF. Comprehensive echocardiography was performed on 149 patients with persistent AF, and E'sr was assessed from three standard apical views using the index beat method. During a median follow-up period of 2.3 years, 63 patients (42.3%) were reaching the renal endpoint. Multivariate analysis showed that an increased E/E'sr ratio (per 10 cm) (hazard ratio, 1.230; 95% confidence interval, 1.088 to 1.391; p = 0.001) was associated with an increased renal endpoint. In a direct comparison, the E/E'sr ratio outperformed the ratio of E to early diastolic mitral annular velocity (E') in predicting progression to the renal endpoint in both univariate and multivariate models (p <= 0.039). Moreover, adding the E/E'sr ratio to a clinical model and echocardiographic parameters provided an additional benefit in the prediction of progression to the renal endpoint (p = 0.006). The E/E'sr ratio is a useful parameter and is stronger than the E/E' ratio in predicting the progression to the renal endpoint, and it may offer an additional prognostic benefit over conventional clinical and echocardiographic parameters in patients with AF.