Cost-Effectiveness of Amiodarone for Prophylaxis of Atrial Fibrillation After Cardiothoracic Surgery

Abstract

To determine whether prophylactic amiodarone, dosed according to Atrial Fibrillation Suppression Trial (AFIST) I and II regimens, is a cost-effective strategy for prevention of postoperative atrial fibrillation. Cost-effectiveness analysis of retrospective cohort study. Urban, academic hospital. A total of 2046 patients who underwent cardiothoracic surgery between February 1, 1998, and October 31, 2003. Of these patients, 186 received amiodarone and 1860 served as controls. Each patient who received prophylactic amiodarone using the AFIST I or II dosing strategies was matched for age, sex, history of valvular surgery, history of atrial fibrillation, beta-blocker intolerance, and receipt of preoperative digoxin therapy with 10 patients who did not receive prophylactic amiodarone. Occurrence of postoperative atrial fibrillation, total hospital costs, and both intensive care unit (ICU) and total hospital length of stay (LOS) were compared between groups. Nonparametric bootstrapping was conducted to examine study results as part of a quadrant analysis and to calculate confidence intervals for the incremental cost-effectiveness ratio. The ICU and total hospital LOS, and total costs for patients with and without postoperative atrial fibrillation were also compared. Fewer patients receiving prophylactic amiodarone developed postoperative atrial fibrillation compared with controls (23.1% vs 29.9%, p=0.05). Total hospital costs for the amiodarone group were 28% less than those for the control group (24,131 US dollars +/- 26,539 vs 33,518 US dollars +/- 40,892, p=0.002). Approximately 98% of the time, patients receiving amiodarone prophylaxis fell into the quadrant that showed superior efficacy and lower total costs. Patients who developed postoperative atrial fibrillation, compared with those who did not, regardless of amiodarone prophylaxis, had a longer mean +/- SD stay in the ICU (6.9 +/- 17.1 vs 3.7 +/- 7.9 days, p<0.001), a longer mean total hospital LOS (14.8 +/- 18.8 vs 10.2 +/- 10.4 days, p+/-0.001), and higher mean total hospital costs (41,574 US dollars +/- 54,721 vs 28,968 US dollars +/- 31,046, p<0.001). Prophylactic amiodarone was shown to reduce the occurrence of postoperative atrial fibrillation as well as total hospital costs in patients undergoing cardiothoracic surgery. In patients who developed postoperative atrial fibrillation, both ICU and total hospital LOS as well as total hospital costs were increased.