The Incidence and Predictors of Postoperative Atrial Fibrillation After Noncardiothoracic Surgery

BACKGROUND AND OBJECTIVES The incidence of postoperative atrial fibrillation after noncardiothoracic surgery is known to be very rare; there have been few prior studies on this topic. We evaluated the incidence, predictors, and prognosis of atrial fibrillation after noncardiothoracic surgery. SUBJECTS AND METHODS Patients who underwent noncardiothoracic surgery at our medical center under general anesthesia were enrolled. We reviewed medical records retrospectively and evaluated whether the atrial fibrillation developed postoperatively or was pre-existing. Patients who had a previous history of atrial fibrillation or atrial fibrillation on the pre-operative electrocardiogram were excluded. RESULTS Between January 2005 and December 2006, 7,756 patients (mean age: 69 years, male: 46%) underwent noncardiothoracic surgery in Samsung Medical Center and 30 patients (0.39%) were diagnosed with newly-developed atrial fibrillation. Patients who developed atrial fibrillation were significantly older and had significantly lower body mass indexes. Newly-developed atrial fibrillation was detected in 0.53% of the male patients and 0.26% of the female patients. The incidence of postoperative atrial fibrillation after an emergency operation was more frequent than that of elective operations (p<0.001). According to the multivariate analysis, age and emergency operations were independent predictors for new onset atrial fibrillation after noncardiothoracic surgery. Postoperative atrial fibrillation developed after a median of 2 days after the noncardiothoracic surgery and was associated with a longer hospitalization and increased in-hospital mortality. Four (13.3%) patients died and the causes of death were non-cardiovascular events such as pneumonia or hemorrhage. CONCLUSION Postoperative atrial fibrillation after noncardiothoracic surgery is a rare complication and is associated with older age and emergency operations. Patients who develop atrial fibrillation have longer hospitalizations and higher in-hospital mortality rates.