Cost-effectiveness of targeting patients undergoing cardiac surgery for therapy with intravenous amiodarone to prevent atrial fibrillation.

OBJECTIVES This study evaluated the cost-effectiveness of administering prophylactic intravenous (IV) amiodarone therapy to patients undergoing cardiac surgery according to their predicted risk of postoperative atrial fibrillation. BACKGROUND Atrial fibrillation (AF) is a common complication of cardiovascular surgery that is associated with a significant increase in hospitalization costs. Intravenous amiodarone has been shown to decrease the incidence of postoperative AF. METHODS All 8,709 patients who underwent coronary artery bypass grafting (CABG), 1,217 patients who underwent valve replacement and 624 patients who underwent CABG and valve replacement procedures (CABG + valve) from January 1, 1994, to June 30, 1999, at Emory University Hospitals were studied. Models predicting the risk of AF were developed using logistic regression; linear regression was used to estimate the influence of AF on hospitalization costs. Cost-effectiveness was evaluated for patient subsets identified according to their predicted risk of AF. RESULTS Postoperative AF rates were 17.7% for CABG, 24.6% for valve and 33.8% for CABG + valve. Using 5,000 dollars as an acceptable cost per episode of atrial fibrillation averted, prophylactic IV amiodarone in CABG patients was not found to be cost-effective. Therapy would be recommended for roughly 5% of valve patients with a predicted risk of atrial fibrillation >45%, and roughly two thirds of CABG + valve patients who have a predicted risk of >30%. CONCLUSIONS Cost-effectiveness of prophylactic IV amiodarone varies according to type of surgery and the predicted risk of atrial fibrillation. Older patients undergoing valve replacement, particularly those with a history of chronic obstructive pulmonary disease, and those undergoing concomitant CABG are likely to be the most appropriate candidates for IV amiodarone therapy in the perioperative period.