Incidence, timing, symptoms, and risk factors for atrial fibrillation after cardiac surgery.

BACKGROUND: Atrial fibrillation is the most common complication after cardiac surgery and a major cause of morbidity and increased cost of care.
OBJECTIVES: To examine the incidence, timing, symptoms, and risk factors for atrial fibrillation after cardiac surgery.
METHODS: A total of 302 patients were continuously monitored for atrial fibrillation with standard hardwire and telemetry devices during hospitalization after coronary artery bypass graft and/or valve surgery and with wearable cardiac event recorders for 2 weeks after discharge from the hospital. After discharge, patients recorded and transmitted their rhythm by telephone daily and whenever they had symptoms suggestive of atrial fibrillation.
RESULTS: Of the 302 patients, 127 (42%) had atrial fibrillation; 41 had it after discharge, and for 10 it was their first episode. The first episode occurred at a mean of 2.9 days after surgery (SD, 3.1; range, day of surgery to 21 days after surgery). Although palpitations was the most common symptom (17%), most episodes of atrial fibrillation (69%) were not associated with symptoms. Independent predictors of atrial fibrillation were age 65 years or greater, history of intermittent atrial fibrillation, atrial pacing, male sex, white race, and not having hyperlipidemia. Independent predictors of atrial fibrillation after discharge from the hospital were having atrial fibrillation while hospitalized, valve surgery, and pulmonary hypertension.
CONCLUSIONS: Atrial fibrillation is common after cardiac surgery and often occurs after discharge from the hospital and without accompanying symptoms. Outpatient monitoring may be warranted in patients with characteristics that place them at increased risk for atrial fibrillation.