Randomized Ablation-based Atrial Fibrillation Rhythm-control Versus Rate-control Trial in Patients With Heart Failure and High-burden Atrial Fibrillation Extend

The RAFT-AF Extend Trial is a continued follow up of patients enrolled in the original RAFT-AF Study (ClinicalTrials.gov, NCT01420393), which evaluated whether ablation-based rhythm-control compared to rate-control improves clinical outcomes in patients with heart failure and atrial fibrillation. It was a randomised, open-label clinical trial, with blinded endpoint adjudication, conducted in 21 institutions in four countries. Patients with atrial fibrillation, New York Heart Association class II-III heart failure, and elevated NT-proBNP were included. Patients were randomized (1:1) to ablation-based rhythm-control or rate-control, stratified by left ventricular ejection fraction (≤45% and >45%). Ablation-based rhythm-control consisted of pulmonary vein isolation in paroxysmal atrial fibrillation, and additional ablation for persistent atrial fibrillation. Rate-control included AV-nodal blocking agents and AV node ablation with permanent pacing. The primary outcome was a composite of mortality and heart failure events, with a minimum follow up of two years. Secondary outcomes included left ventricular ejection fraction, quality of life, six-minute walk test and NT-proBNP. The primary analysis was intention-to-treat. From December 1, 2011, to January 20, 2018, 411 patients were randomised to ablation-based rhythm-control (n=214) or rate-control (n=197). The primary outcome occurred in 50 (23·4%) patients in the ablation-based rhythm-control group and 64 (32·5%) patients in the rate-control group (hazard ratio 0·71 95% CI (0·49, 1·03), p=0·066). Quality of life, six-minute walk distance, left ventricular ejection fraction, and NT-proBNP demonstrated greater improvements in the ablation-based rhythm-control group.

In patients with high burden atrial fibrillation and heart failure, there was no statistically significant reduction of all-cause mortality or heart failure events with ablation-based rhythm-control versus rate-control. With the hazard ratio equivalent to the minimal clinically important difference and the result near statistical significance, there is a probable clinically important benefit of ablation-based rhythm-control over rate-control.

This RAFT-AF Extend study is to extend follow up in RAFT-AF patients for an additional 24 months in order to have sufficient power to definitely determine if ablation-based rhythm control of atrial fibrillation is superior to rate control for the reduction of the primary outcome of all-cause mortality or heart failure event in patient with atrial fibrillation and heart failure.