Incidence of atrial fibrillation after mild or moderate hypothermic cardiopulmonary bypass

Objectives: Atrial fibrillation remains a significant source of morbidity a fter coronary artery bypass grafting (CABG), Whether cardiopulmonary bypass (CPB) temperature influences the occurrence of postoperative atrial fibril lation in CABG patients has not been specifically examined. In the present study, we reviewed postoperative data from patients who were prospectively randomized to mild or moderate hypothermic CPB for elective CABG to determi ne the incidence of postoperative atrial fibrillation. Design: Randomized, single center, observational study. Setting: Tertiary university medical center. Patients: Adults undergoing elective CABG surgery. Interventions: Enrolled patients were prospectively randomized to mild (34 degrees C [93.2 degrees F]) or moderate (28 degrees C [82.4 degrees F]) hyp othermic CPB. Measurements and Main Results: The incidence of postoperative atrial fibril lation was determined by review of ICU and hospital records. There was a si gnificantly higher incidence of atrial fibrillation in the moderate compare d with the mild hypothermic CPB group. Patients who had postoperative atria l fibrillation were significantly older than those without atrial fibrillat ion, Furthermore, a significant increase in the relative risk of developing postoperative atrial fibrillation was found for both age and CPB temperatu re. Conclusions: Our results indicate that the temperature of systemic cooling during CPB is an important factor in the development of atrial fibrillation after CABG surgery. In addition, this study confirms that increasing age i s a significant determinant of postoperative atrial fibrillation.