WASHINGTON, DC—In cardiac surgery, the use of peri-operative amiodarone is associated with lower yet earlier incidence of atrial fibrillation (AF) compared to the use of beta blockers. Findings from this study, led by Irene Kirolos, were presented at the ACC.17 Scientific Session.

Treatment to prevent post-operative AF in patients undergoing cardiac surgery continues to be controversial. In order to get a better understanding of treatment outcomes, researchers compared the use of amiodarone to beta blockers to see which therapy would decrease the incidence of post-op AF.

They conducted a literature search using several databases (PubMed, MEDLINE, EMBASE, SCOPUS, COCHRANE, and GOOGLE SCHOLAR from 1988–present) which yielded 136 studies, eight of which were selected for the review. In addition to post-op incidence of AF (the primary outcome), the researchers looked at onset, duration of AF, and ventricular response rate (secondary outcomes).

Of the 1457 patients included in the study, 1397 underwent coronary artery bypass graft, 24 had vascular surgery and 36 had both; no significant differences between these groups were noted (ie, age, sex, smoking status, co-morbidities, cardiac vessels involved).  Seven hundred and twenty-two patients received amiodarone while 735 received beta blocker (often metoprolol).

Significantly less incidence of AF was seen in the amiodarone group (RR 0.75; 95% CI:0.58–0.97, P=0.029), while the onset of AF was delayed in patients in the beta blocker group (SMD 0.43; CI:0.08–0.76, P=0.014). With regards to the other secondary endpoints, no significant difference was seen between the two groups in AF duration (SMD –0.28; 95% CI:–1.01 to 0.46, P=0.45) or ventricular response rate (SMD 0.58; 95% CI:–0.51–1.68, P=0.29).

“Randomized clinical trials are needed to validate this finding and further investigate independent risk factors associated with post-operative AF,” the authors concluded.