Brief Report
Rate Versus Rhythm Control in Heart Failure Patients with Post-Operative Atrial Fibrillation After Cardiac Surgery

https://doi.org/10.1016/j.cardfail.2021.02.016Get rights and content

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

Introduction

Post-operative atrial fibrillation (POAF) occurs in up to one third of cardiac surgical procedures.1 An understanding of how best to treat POAF is essential. Treatment strategies include “rate control” and “rhythm control.” The Cardiothoracic Surgical Trials Network conducted a multicenter randomized trial of rate versus rhythm control in POAF.2 There were no differences in outcome between the strategies, and 25% of study participants crossed over to the unassigned treatment. The patient characteristics predicting clinical response to rate control versus rhythm control remain unclear, representing a gap in knowledge.

Patients with heart failure are vulnerable to hemodynamic adverse effects of POAF.3 Moreover, clinicians often pursue a rhythm control strategy in heart failure patients with POAF. Whether a rate control or a rhythm control strategy is best for management of POAF in patients with known heart failure is not known. We hypothesize that patients with a history of heart failure would have improved outcomes with rhythm control. Therefore, we assessed whether heart failure history or systolic dysfunction is an effect measure modifier of the relationship between rate versus rhythm control and outcome in POAF after cardiac surgery.

Section snippets

Study population

We performed a stratified analysis of the CTSN-POAF trial.2 Trial data was obtained from the NIH BioLINCC data repository.4 The CTSN-POAF trial randomized 523 patients with POAF after cardiac surgery to rate or rhythm control. Subjects had CABG, valve procedure or a combined valve-CABG. Follow-up time began at time of randomization. The heart rhythm was assessed by electrocardiography at hospital discharge, study day 30 and study day 60. Patients receiving mechanical valves, those who were

Results

Of 523 subjects, 131 (25%) had HF. Demographics, clinical characteristics and outcomes for POAF HF subjects compared to those without HF are shown in the Table. Similar proportions of POAF HF and non-HF subjects required crossover to the alternate management strategy- 28% of HF subjects and 24% of non-HF subjects. Outcomes of subjects with POAF were similar in the HF and non-HF groups, with between 23 and 25% 30-day readmission rates, low death rates, and similar numbers of days alive and out

Discussion

In this stratified analysis of a randomized trial of rate versus rhythm control to treat post-operative atrial fibrillation after cardiac surgery, we report several major findings. A substantial percentage of HF patients with POAF treated with either initial rate or rhythm control will require crossover to the other treatment strategy for efficacy or intolerance, supporting that clinicians must continually re-evaluate their initial treatment strategy. In addition, an initial rhythm control

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