Abstract 151: Outcomes Associated With Prophylactic Amiodarone Protocol in Patients Undergoing Cardiac Surgery: A Single Center Experience

Abstract

Background: The incidence of post-operative atrial fibrillation (POAF) in patients undergoing cardiac surgery is approximately 25-40% and has significant consequences. One large randomized control trial demonstrated that the use of amiodarone prophylaxis decreases the incidence of POAF. To improve the quality of care for cardiac surgery patients and improve outcomes, an amiodarone prophylaxis protocol was implemented at our institution in July 2007. The protocol consisted of administering intravenous amiodarone (150 mg) after surgery, in patients without contraindications, followed by a week of 400 mg of oral amiodarone twice a day and 200 mg daily for one more week. In order to encourage utilization, an order care set was created in the electronic medical record system. We studied the effect of this intervention on practice and clinical outcomes. Methods: We included all patients ≥ 18 years of age without pre-existing atrial fibrillation, undergoing cardiac surgery in 5-year periods before and after the implementation of the amiodarone prophylaxis protocol in July 2007. Data were obtained from the Society of Thoracic Surgery (STS) National Database. The primary outcome was the rate of utilization of amiodarone and secondary outcomes were incidence of STS-defined POAF, stroke, myocardial infarction (MI) and 30-day mortality. Outcomes in the January 2002 to July 2007 time-period were compared with those in the September 2007 to June 2012 time-period. Results: From January 2002 to June 2012, 5473 patients underwent cardiac surgery. The mean age was 66 years, 69% were male and 93% were Caucasian. In the September 2007 to June 2012 time-period, 54% of patients (1303 of 2405) received amiodarone as compared to 11% of patients (330 of 3068) in the January 2002 to July 2007 time-period (p<0.01). The STS-defined incidence of POAF decreased in the September 2007 to June 2012 time-period as compared to the January 2002 to July 2007 time-period [36% (861 of 2405) vs. 38% (1178 of 3068), p= 0.04]. The incidence of stroke [4% (93 of 2405) vs. 6% (103 of 1696), p<0.01] and peri-operative MI [4% (90 of 2405) vs. 12% (378 of 3068), p<0.01] decreased as well but there was no change in 30 day mortality [2% (55 of 2405) vs. 2% (78 of 3068), p = 0.55]. Conclusions: Implementation of an amiodarone prophylaxis protocol order care set was associated with greater utilization of amiodarone. It was also associated with a modest decrease in the incidence of STS-defined POAF, stroke and MI but was not associated with a change in 30-day mortality in patients undergoing cardiac surgery. Further studies are needed to study the cost-effectiveness and risk-benefit analysis of routine amiodarone as prophylaxis.