Abstract

BACKGROUND: Whether rhythm control for post-operative atrial fibrillation after cardiac surgery (POAF) is superior to rate control in patients with heart failure or systolic dysfunction (HF) is not known. METHODS: We performed a post-hoc analysis of a trial by the Cardiothoracic Surgical Trials Network, which randomized patients with POAF after cardiac surgery to rate control or rhythm control with amiodarone/cardioversion. We assessed subgroups of trial participants defined by heart failure/cardiomyopathy history or left ventricular ejection fraction (LVEF) < 50%. We conducted a stratified analysis in patients with and without HF to explore outcomes of rhythm versus rate control strategy. RESULTS: Of 523 subjects with POAF after cardiac surgery, 131 (25%) had HF. 49% of HF patients were randomized to rhythm control. In HF patients, rhythm control was associated with less atrial fibrillation within the first 7 days. There were no differences in rhythm at 30- and 60-day follow-up. In the HF group, there were significantly more subjects with AF < 48 hours in the rhythm control group compared to rate control group- 68.8% compared to 46.3%, P=0.009. By comparison, in the non-HF stratum, 54.4% of the rate control group had AF < 48 hours compared to 63.5% of the rhythm control group (P=0.067).), though there was no significant interaction of heart failure with cardiac rhythm at 7 days (Pinteraction 0.16). CONCLUSION: Rhythm control for HF patients with POAF after cardiac surgery increases early restoration of sinus rhythm. Rate and rhythm control are both reasonable for HF patients with AF after cardiac surgery.