Value of tissue doppler indices for prediction of early atrial fibrillation recurrence after cardioversion

Abstract Background Spectral tissue Doppler-derived E/e' ratio has been proposed as the best parameter in the prediction of atrial fibrillation (AF). Although relaxation and contraction are equivalent parts of a continuous cardiac cycle, where systolic and diastolic abnormalities have a variable contribution to the left ventricle (LV) failure. A new doppler index, E/(e'×s') ratio, combining an index of diastolic function (E/e') and marker of systolic LV function (s'), has been confirmed as a good predictor of new-onset AF, although value of E/(e'×s') ratio to predict AF recurrence was not evaluated. Purpose The aim of this study was to investigate whether E/(e'×s') may be better parameter than E/e' to predict AF recurrence after the electrical cardioversion (ECV) of persistent AF in patients with normal LV function. Methods The prospective study included 77 patients with persistent AF with preserved LV ejection fraction (>50%) and successfully performed ECV. Plasma level of NT-proBNP was measured for all the patients before the ECV. Transthoracic echocardiography was performed within the first 24 hours after successful ECV. Primary outcome was the early (at 1 month) recurrence of AF. Results At 1 month follow-up, 39 patients (50.6%) were in sinus rhythm. Binary logistic regression analysis showed that LV enddiastolic diameter >50 mm (HR 3.70, 95% CI 1.29–10.58, p=0.02), NT-proBNP >2000 ng/L (HR 3.28, 95% CI 1.01–10.71, p=0.04), E/e' (HR 1.74, 95% CI 1.27–2.39, p=0.001) and E/(e'×s') ratios (HR 8.17, 95% CI 1.57–42.4, p=0.01) were significant predictors of AF early recurrence after ECV. When we developed multivariate models using these potential confounding factors. To minimize the problem of collinearity E/e'and E/(e'×s') were included in 2 separate models. Multivariate analysis identified that E/(e'×s') ratio and E/e' ratio in combination with LV enddiastolic diameter >49.3 mm and NT-proBNP >2000 ng/L are able to predict early AF recurrence after ECV in 74% and 79% cases, respectively. E/(e'×s') ratio showed higher contribution in the model to predict AF recurrence compared to E/e' ratio (for E/(e'×s') ratio HR 18.94, 95% CI 2.39–149.66, p=0.005; for E/e' ratio HR 1.95, 95% CI 1.31–2.91, p=0.001). On ROC analysis, the diagnostic accuracy of E/(e'×s') and E/e' ratios were found to have the largest areas under the curve (E/(e'×s') ratio, AUC = 0.71, p=0.002 and E/e' ratio, AUC = 0.75, p