Rate-control versus conversion strategy in postoperative atrial fibrillation: A prospective, randomised pilot study

Background Atrial fibrillation remains a frequent complication after heart surgery. The optimal strategy to treat the condition has not been establish ed. Several retrospective studies have suggested that a primary rate-contro l strategy may be equivalent to a strategy that restores sinus rhythm. Methods Fifty patients with atrial fibrillation after heart surgery were ra ndomly assigned to a strategy of antiarrhythmic therapy with or without ele ctrical cardioversion or ventricular rate control. Both arms received antic oagulation with heparin overlapped with warfarin. The primary end point was time to conversion to sinus rhythm analyzed by the Kaplan-Meier method. At rial fibrillation relapse after the initial conversion was monitored in the hospital over a 2-month period. Results There was no significant difference between an antiarrhythmic conve rsion strategy (n = 27) and a rate-control strategy (n = 23) in time to con version to sinus rhythm (11.2 +/- 3.2 vs 11.8 +/- 3.9 hours; P=.8). With th e use of Cox multivariate analysis to control for the effects of age, sex, P-blocker usage, and type of surgery, the antiarrhythmic strategy showed a trend toward reducing the time from treatment to restoration of sinus rhyth m (P=.08). The length of hospital stay was reduced in the antiarrhythmic ar m compared with the rate-control strategy (9.0 +/- 0.7 vs 13.2 +/- 2.0 days ; P=.05). In-hospital relapse rates in the antiarrhythmic arm were 30% comp ared with 57% in the rate-control strategy (P=.24). There were no significa nt difference in relapse rates at 1 week (24% vs 28%), 4 weeks (6% vs 12%), and 6 to 8 weeks (4% vs 9%), At the end of the study, 91% of the patients in the rate-control arm were in sinus rhythm compared with 96% in the antia rrhythmic arm (P=.6). Conclusions This pilot study shows little difference between a rate-control strategy and a strategy to restore sinus rhythm. Regardless of strategy, m ost patients will be in sinus rhythm after 2 months. A larger randomized, c ontrolled study is needed to assess the impact of restoration of sinus rhyt hm on length of stay.