Post-discharge recurrences of new-onset atrial fibrillation following cardiac surgery: impact of low-dose amiodarone and beta-blocker prophylaxis

Abstract

Background: Atrial fibrillation (AF) is the most frequent complication following cardiac surgery. It occurs mostly between the second and fourth postoperative days and often recurs within 30 days after surgery. While postoperative AF has been well analyzed, post-discharge recurrences of AF have not been clearly described even if they are reported as a frequent cause of re-hospitalization.

Methods: We followed up 185 patients for 10 +/- 5 months with the aim of characterizing the post-discharge recurrences of AF. All patients had recently undergone cardiac surgery complicated by AF and were in sinus rhythm at the time of admission to our Center. We also compared the efficacy of the main prophylactic regimens adopted in the referral Centers (amiodarone, beta-blockers, amiodarone plus beta-blockers) during the first postoperative month.

Results: In the first postoperative month AF recurred after discharge in 60 patients. The event rate was not different in patients treated with amiodarone and controls (47 vs 50%, p = NS), while it was significantly lower in patients taking beta-blockers either alone or associated with amiodarone (10 and 9% respectively, p = 0.002). At the end of follow up (10 +/- 5 months), AF persisted in 3 out of 176 study patients (1.7%).

Conclusions: In patients undergoing cardiac surgery, post-discharge recurrences of AF are frequent during the first postoperative month and have a clinical relevance. Beta-blockers (not amiodarone) seem to be an effective prophylactic measure. The phenomenon tends to vanish in the long term, and a chronic prophylaxis is not justified.