Take It Slow or Move to the Rhythm?

Volume 6, Issue 3

Atrial fibrillation is the most common arrhythmia in the United States, with an incidence rate that continues to rise as the population ages. Prior studies have conclusively shown no benefit for routine antiarrhythmic drug therapy, hence most patients with symptomatic atrial fibrillation (AF) are treated first with rate control therapy (ie, suppressing tachycardia with heart rate slowing therapy).

Recently this notion was challenged with the completion of the Early Treatment of Atrial Fibrillation for Stroke Prevention Trial - EAST-AFNET 4. In this week’s issue of Talking Therapeutics, we explore this exciting new trial and its implications for patients with atrial fibrillation.

Point 1: Early rhythm control may provide superior outcomes

The goal of the trial was to compare a rhythm-control strategy vs usual care (rate control in the majority of cases) among patients with a recent diagnosis (within 1 year) of AF. In the rhythm-control arm, initial choice of strategy was flecainide 36%, amiodarone 20%, and catheter ablation 8%. The median days from AF diagnosis was 36. The trial was stopped early due to efficacy.

The primary outcome of cardiovascular (CV) death, stroke, hospitalization for heart failure, or acute coronary syndrome was 3.9 vs 5.0/100 person-years (P-Y) (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.66-0.94, P=.005) for rhythm control vs usual care, respectively. This difference was primarily driven by lower rates of CV death and stroke.

Point 2: Benefits are consistent for those with heart failure

For the subset of patients with concomitant heart failure (798), the majority had HF with preserved EF. The composite outcome for rhythm control vs. usual care was 5.7 vs. 7.9/100 P-Y (HR 0.74, 95% CI 0.56-0.97, P= 0.03) (p for interaction=.63). Hospitalization for worsening of HF was 3.9% vs. 4.7% (P=.91).

The results of this trial indicate that a rhythm-control strategy is superior to rate control in improving CV outcomes at 5 years among patients with recent diagnosis of AF and concomitant CVD. Of note, these results were similar in the subgroup of patients with HF. Results of this trial are different from other similar trials such as CABANA-AF, AFFIRM, and RACE, which likely reflects the more recent onset of AF in this trial. There was also a reasonably high rate of AF ablation (8% at enrollment, 20% by 5 years) in the current trial. Unfortunately, this trial is only single-blinded (not to intervention received), and hence residual confounding cannot be excluded.

Disclaimer: The views and opinions expressed are those of the author(s) and do not necessarily reflect the official policy or position of the Population Health Learning Network or HMP Global, their employees, and affiliates. Any content provided by our bloggers or authors are of their opinion and are not intended to malign any religion, ethnic group, club, association, organization, company, individual, or anyone or anything. 

References:

1. Rillig A, Magnussen C, Ozga A et al. Early Rhythm Control Therapy in Patients with Atrial Fibrillation and Heart Failure. Circulation. 2021. doi:10.1161/circulationaha.121.056323
2. Kirchhof P, Camm A, Goette A et al. Early Rhythm-Control Therapy in Patients with Atrial Fibrillation. New England Journal of Medicine. 2020;383(14):1305-1316. doi:10.1056/nejmoa2019422