Very Late Effects of Postoperative Atrial Fibrillation on Outcome of Coronary Artery Bypass Graft Surgery

BACKGROUND: Atrial fibrillation (AF) after coronary artery bypass graft (CABG) is a common complication with potentially higher risk of adverse outcome and prolonged hospital stay. OBJECTIVE: To determine the impact of postoperative AF (POAF) on long-term outcome in a large cohort of patients who underwent CABG. PATIENTS AND METHODS: We conducted an observational cohort study of 989 patients who underwent isolated CABG with more than 5-year follow-up. Patient divided in two groups: patients with and without POAF. RESULTS: In this study, atrial fibrillation developed after CABG in 156 patients (15.8%). Patients with POAF were generally older (P = 0.001) and presented more often with comorbidities including congestive heart failure (P = 0.001), hypertension (P = 0.001), peripheral vascular disease (P = 0.001), hyperlipidemia (P = 0.009), and renal failure (P = 0.001). Five-year mortality was observed in 23 (2.3%) patients. Patients with POAF had higher five-year mortality rate than those without POAF. Multivariate logistic analysis showed that AF after surgery has a strong effect on mortality (HR, 3.3; 95% CI, 0.04-10.8, P = 0.04) and morbidity rates (HR, 4.0; 95% CI, 2.35-6.96, P = 0.001). CONCLUSIONS: Postoperative atrial fibrillation strongly predicts higher long-term mortality and morbidity following coronary artery bypass graft.