New onset postoperative atrial fibrillation is associated with a long-term risk for stroke and death following cardiac surgery

Background and aim: We sought to evaluate the long-term impact of post-cardiac surgery atrial fibrillation on the risk of stroke and survival. Methods: Patients undergoing isolated CABG surgery from April 1, 1995 to March 31, 2007 were identified (n = 8058). Long-term stroke data were compiled using Cox modeling adjusted for clinical characteristics comparing patients with new-onset atrial fibrillation (NwAfib) and those without. Results: NwAfib developed in 2214 patients (27.5%). Overall in-hospital mortality was 2.4% and was not different between groups. Unadjusted in-hospital outcomes suggest patients with NwAfib were more likely to suffer a permanent stroke (1% vs 2.5%; p < 0.001) require prolonged mechanical ventilation (p < 0.001) and prolonged stay in hospital (p < 0.001). After discharge patients were followed for a mean of 5.7 years. Stroke was reported in 268 (12.1%) patients in the NwAfib group compared to others (8.4%). After adjustment NwAfib was independently associated with a higher risk for stroke with a hazard ratio of 1.26 (1.08-1.47; p = 0.0034) and a higher risk of death with a hazard ratio of 1.2 (1.08-1.32; p = 0.0007). Conclusions: Patients with NwAfib perioperatively have increased risk of stroke and early death after discharge independent of other clinical risk factors.