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.