Predictors of atrial fibrillation after conventional and beating heart coronary surgery - A prospective, randomized study

Background-Atrial fibrillation (AF) increases the morbidity of CABG. The pa thophysiology is uncertain, and its prevention remains suboptimal. This pro spective, randomized study was designed to define the role of cardiopulmona ry bypass (CPB) and cardioplegic arrest in the pathogenesis of this complic ation. Methods and Results-Two hundred patients were prospectively randomized to ( 1) on-pump conventional surgery [(100 patients, 79 men, mean age 63 (40 to 77) years)] with normothermic CPB and cardioplegic arrest of the heart or ( 2) off-pump surgery [(100 patients, 82 men, mean age 63 (38 to 86) years)] on the beating heart. Heart rate and rhythm were continuously monitored wit h an automated arrhythmia detector during the first 72 hours after surgery. Thereafter, routine clinical observation was performed and continuous moni toring restarted in the case of arrhythmia. The association of perioperativ e factors with AF was investigated by univariate analysis. Significant vari ables were then included into a stepwise logistic regression model to ascer tain their independent influence on the occurrence of AF. There were no sig nificant baseline differences between groups. Thirty-nine patients in the o n-pump group and 8 patients in the off-pump group had postoperative sustain ed AF (P=0.001). Univariate analysis showed that CPB inclusive of cardiople gic arrest, postoperative inotropic support, intubation time, chest infecti on, and hospital length of stay were predictors of AF (all P<0.05). However , stepwise multivariate regression analysis identified CPB inclusive of car dioplegic arrest as the only independent predictor of postoperative AF (OR 7.4; CI 3.4 to 17.9). Conclusions-CPB inclusive of cardioplegic arrest is the main independent pr edictor of postoperative AF in patients undergoing coronary revascularizati on.