Early Transthoracic Echocardiography after Cardiac Surgery Predicts Postoperative Atrial Fibrillation

Postoperative atrial fibrillation (POAF) is frequent after cardiac surgery. We aimed to establish a predictive model of POAF based on postoperative transthoracic echocardiography (TTE) findings.

This study included 147 patients (aged 67 ± 11 years; 109 men) undergoing coronary artery bypass grafting and/or aortic valve replacement. TTE and Doppler tissue imaging were performed on intensive care unit arrival after surgery. All patients were continuously monitored during hospitalization. The end point was the appearance of POAF.

POAF appeared in 37 patients (25.2%). These patients were older (69 ± 16 vs. 65 ± 12 years; P < 0.001) and had increased long axis of the left atrium (LA) dimension (5.4 ± 1 vs. 4.8 ± 0.9 cm, P = 0.02), lower early diastolic velocity of the mitral annulus (e') (6.9 ± 2.1 vs. 8 ± 1.8 cm/sec; P < 0.01), and higher early diastolic pulsed Doppler mitral ratio (E)/e' (E/e') (17.4 ± 6.8 vs. 13.8 ± 6; P = 0.01). Left ventricle diastolic dysfunction grade (DFG) of 2 or 3 relative to grade 0 was significant: odds ratio (OR) 22.5, 95% confidence interval (CI) 4.52-57.2; P < 0.001, and OR: 23.6, 95% CI: 3.57-60.1; P = 0.001), respectively. On multivariate analysis, the independent predictors of POAF were age (OR: 1.10, 95% CI: 1.01-1.18; P < 0.05), long-axis LA dimension (OR: 6.24, 95% CI: 1.97-8.23; P = 0.0017), DFG-2 (OR: 4.1, 95% CI: 1.57-15.81; P < 0.001), and DFG-3 (OR: 8.3, 95% CI: 4.11-25.37; P < 0.001).

Apart from age, the simple determination by postoperative TTE of long-axis LA dimension and DFG after cardiac surgery proved to be powerful independent predictors of POAF and may be useful for risk stratification of these patients.