Diastolic dysfunction, cardiopulmonary bypass, and atrial fibrillation after coronary artery bypass graft surgery

Background. Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery, and is associated with increased morbidity, mortality, and utilization of healthcare resources. Diastolic dysfunction (DD) causes a range of changes in left atrial structure and function that may predispose patients to increased risk of AF. We hypothesized that patients with either new or worsened grade of DD after cardiopulmonary bypass (CPB) would have higher prevalence of AF after CABG surgery. The current study sought to determine an association between the dynamic changes in diastolic function during the perioperative period and postoperative AF in patients undergoing CABG surgery. Methods. A total of 109 patients undergoing elective CABG surgery were assessed for the presence of DD before and after CPB. All patients were monitored for the development of AF after surgery for the entire hospital stay. Results. DD was present in 89 (81%) and 91 (83%) patients before and after CPB. Thirty-four (31%) patients had either new or worsened grade of DD after CPB. Postoperative AF was present in 30 (27.5%) patients, including 15 (44%) patients with either new or worsened DD, and 15 (20%) patients with either unchanged or improved DD (P=0.009). Independent predictors of postoperative AF included age >= 65 yr [odds ratio (OR) 4.207, 95% confidence interval (CI) 1.527, 11.5881, and new or worsened DD (OR 4.145, 95% CI 1.519, 11.356). Conclusions. New or worsened DD after CABG surgery is associated with an increased incidence of postoperative AF.