Background: Atrial fibrillation (AF) is a common occurrence after heart operations that use cardiopulmonary bypass. It can cause life-threatening complications as well as delay discharge and increase hospitalization costs. The purpose of this study was to evaluate the effect of orally administered low-dose amiodarone on the incidence of new onset postoperative AF.
Methods: In this prospective study, 226 consecutive adult patients (group A) who had various heart operations utilizing cardiopulmonary bypass between April and November of 1998 at the University of Miami/Jackson Memorial Hospital, were given oral amiodarone (200 mg three times a day), starting immediately after arrival in the intensive care unit until the day of hospital discharge. The incidence of new AF in this group of patients was assessed and compared with a historical group of 239 patients (group B) who had had cardiac operations with cardiopulmonary bypass in the preceding 9 months at the same institution.
Results: Preoperative patient characteristics and procedure types were similar in the two groups. Among the 226 patients in group A, 13 (5.7%) had history of AF. Of the remaining 213 patients, new-onset AF occurred postoperatively in 10 (4.7%). Among the 239 patients in group B, 16 (6.7%) had history of AF. Of the remaining 223 patients, 44 (19.7%) developed new-onset AF (p < 0.001). Group A patients had a shorter length of hospital stay than those in group B (6.5 versus 7.8 days) but had a similar incidence of complications other than AF (23 of 226 patients in group A versus 24 of 239 in group B). The drug was well tolerated.
Conclusions: Postoperative low-dose amiodarone given orally to patients who had cardiopulmonary bypass was well tolerated and appeared to reduce the incidence of new-onset AF and decrease the length of hospital stay.