Use of intraoperative transesophageal echocardiography to predict atrial fibrillation after coronary artery bypass grafting

Background Postoperative atrial fibrillation in coronary artery bypass graf t surgery occurs in 10-40% of patients. It is associated with a significant degree of morbidity and results in prolonged lengths of stay in both the i ntensive care unit and hospital. Methods; The authors prospectively evaluated patients undergoing coronary a rtery bypass with detailed transesophageal echocardiography examinations co nducted before and after cardiopulmonary bypass to study whether risk facto rs for atrial fibrillation could be identified. Demographic and surgical pa rameters were also included in the analysis. Selected variables were subjec ted to univariate and subsequent multivariate analyses to test for their In dependent or joint Influence on atrial fibrillation. Results: Seventy-nine patients had assessable transesophageal echocardiogra phy examinations. Significant univariate predictors of atrial fibrillation included advanced age (P = 0.002), pre-cardiopulmonary bypass left atrial a ppendage area (P = 0.04), and post-cardiopulmonary bypass left upper pulmon ary vein systole/diastole velocity ratio (P = 0.03). When these three facto rs were considered together in a multiple logistic regression analysis, lef t upper pulmonary vein systole/diastole velocity ratio was a significant pr edictor (P < 0.05), as was the joint effect of age plus pre-cardiopulmonary bypass left atral appendage area (P = 0.005). The probability of developin g atrial fibrillation for the combination of age = 75 yr, post-cardiopulmon ary bypass left upper pulmonary vein systole/diastole velocity ratio = 0.5, and left atrial appendage area = 4.0 cm. was 0.83 (95% confidence interval , 0.51-0.96). Conclusions: Early identification of patients at risk for postoperative atr ial fibrillation may be feasible using the parameters Identified In this st udy.