Atrial fibrillation and heart failure are two common, costly medical conditions that are increasing in prevalence and incidence in the United States. These two comorbidities often accompany one another in the advanced heart failure population. While goal directed medical therapy for those with heart failure with reduced ejection fraction exists, there is limited evidence of therapy for those with concurrent heart failure and atrial fibrillation.
Prior research from the CASTLE-AF trial has shown benefit from catheter ablation for drug resistant atrial fibrillation for those with heart failure in regard to all cause death and heart failure hospitalization. However, little is known regarding the benefit of rhythm control strategy with catheter ablation and antiarrhythmic drugs when compared to rate control alone.
Dr Anthony Tang, Professor of Medicine at Western University and Adjunct Professor of Medicine in the Faculty of Medicine at the University of Ottawa, presented his results from the RAFT-AF study at day 3 of ACC 2021. In this prospective, multicenter, randomized, open blinded study, 600 patients with NYHA class II-III heart failure (which included those with heart failure with reduced ejection and heart failure with preserved ejection fraction) were randomized to ablation with and without antiarrhythmic drugs versus rate control for concurrent management of heart failure and atrial fibrillation. Rhythm control was further defined as those treated with pulmonary vein isolation and antiarrhythmic drugs if any atrial fibrillation recurrence was detected.
The primary outcome assessed was a composite outcome of time to death or heart failure event. The study was stopped early due to a lower than anticipated enrollment and event rate. While there was clearly a trend towards benefit in the primary outcome for patients undergoing an ablation-based rhythm control strategy when compared to rate control, the P value was not significant (hazard ratio 0.71, CI o0.49-1.03, P=0.066). The trend was stronger, although still not significant, for patients with an ejection fraction of ≤45%. Reassuringly, there was no increase in adverse events in the intervention arm when compared to the control group. Limitations of the study include that the trial was stopped early and was therefore underpowered to detect a statistically significant result.
When asked about the clinical implications by ACC, Dr Tang admitted “It’s not quite as conclusive as I’d like it to be, but I think it still is useful to help individual physicians determine treatment strategies.” While enrollment of the study was only 411 patients, Dr Tang believes RAFT-AF did show a benefit for ablation in those with heart failure with reduced ejection fraction and plans on incorporating this into his clinical practice.
RAFT-AF was sponsored by the Ottawa Heart Institute Research Corporation. RAFT-AF ClinicalTrials.gov number, NCT01420393