QS237. Results of a Protocol Based Practical Approach for the Prevention of Postoperative Atrial Fibrillation Following Cardiac Surgery

Abstract

Introduction: Atrial fibrillation is a common complication following cardiac surgery and is associated with increased postoperative morbidity and mortality. Studies have indicated the incidence of postoperative atrial fibrillation to be as high as 33% after coronary artery bypass grafting and 48.8% after isolated valve surgery. Prophylactic amiodarone use has been shown to decrease the incidence of postoperative atrial fibrillation. The purpose of this study was to prospectively evaluate the effectiveness of a cardiac surgery atrial fibrillation prophylaxis protocol used in conjunction with electrolyte replacement protocols. Methods: We studied the data collected for and submitted to the Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database for 198 consecutive patients undergoing cardiac surgery. Adult cardiac surgery patients were placed on an amiodarone protocol and on potassium and magnesium replacement protocols. Patients received a loading dose of either 6000 mg oral amiodarone or 3000 mg intravenous amiodarone. The loading dose was started preoperatively whenever possible. After completion of the loading dose, patients received a daily maintenance dose of 200 mg orally for a total of a 30 day course. The potassium and magnesium replacement protocols aimed to maintain a serum potassium level between 4.0 and 5.5 mEq and a serum magnesium level greater than 2 mg/dL. Data collected and examined included patient demographics, clinical and operative procedures, and patient outcomes. Data were compared to published and predicted values. Results: The overall incidence of postoperative atrial fibrillation in the study population was 18.6%. A total of 109 patients had isolated coronary artery bypass grafting. The incidence of postoperative atrial fibrillation was 18.3% in patients who had isolated coronary artery bypass grafting. A total of 33 patients received an isolated valve surgery inclusive of mitral valve replacement, mitral valve repair, aortic valve replacement, or tricuspid valve replacement. The incidence of postoperative atrial fibrillation was 18.2% in patients who received an isolated valve surgery. Conclusions: This prospective analysis indicates prophylactic treatment with amiodarone in conjunction with the implementation of standardized electrolyte replacement protocols may be an effective way to prevent postoperative atrial fibrillation.