Ablation in AF Improves Exercise Capacity, QOL in Heart Failure Patients

The strategy of catheter ablation–based rhythm control in patients with long-standing persistent atrial fibrillation (AF) plus heart failure (HF) was found superior to pharmacologic rate control for improving cardiopulmonary exercise capacity (measured as peak VO₂); quality of life (QOL); and neurohormonal status in a small, randomized study reported March 5 online in the Journal of the American College ofCardiology. 

According to the authors of the Catheter Ablation Versus Medical Rate Control for Atrial Fibrillation in Patients with Heart Failure (ARC-HF)¹ study, the majority of improvement in these endpoints was seen 3 to 12 months after an initial ablation procedure. 

Senior investigator Dr Tom Wong of the Imperial College of London notes that AF is common in patients with HF; it is also particularly difficult to manage in HF patients; often they are resistant to drug therapy for maintenance of sinus rhythm.² They also tend to be highly symptomatic, with diminished cardiac output related to loss of atrial contractility.²

The ARC-HF trial included 52 patients who had persistent AF for an average of 24 months. Patients were assigned randomly to 1 of 2 groups: 26 to receive catheter ablation and 26 to receive  contemporary standard-of-care rate control therapy with beta-blockers and/or digoxin. At 12 months, 88% of the ablation patients were in normal sinus rhythm and 96% had achieved rate control. Peak VO₂ increased 2.13 mL/kg per minute in the ablation group, but declined over time in the rate control group, with a 12-month intergroup difference of 3.07 mL/kg per minute. A significant reduction in baseline left atrial dilatation, documented at 6 months, was maintained at 12 months. There also was a nonsignificant trend toward improved left ventricular ejection fraction in the catheter ablation group.

This is the first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF. As noted in the study abstract, development of the effects over 12 months is consistent with progressive amelioration of the HF syndrome.¹

QOL, as measured by the Minnesota Living with Heart Failure Questionnaire, also improved among patients in the ablation group as did neurohormonal status as reflected by reductions in brain natriuretic peptide levels.

The ablation procedure is lengthy and difficult, averaging more than 5 hours, including 80 minutes of fluoroscopy and approximately 82 minutes of actual ablation.

Investigator Wong notes that while they are promising, results of the study will need to be confirmed by larger randomized trials. ²References:
1. Jones DG, Haldar SK, Hussain W, et al. A randomized trial to assess catheter ablation versus rate control in the management of persistent atrial fibrillation in heart failure (ARC-HF). J Am Coll Cardiol. March 2013. doi:10.1016/j.jacc.2013.01.069.

2. O’Riordan M. Ablation of AF improves exercise capacity in heart-failure patients. Heartwire Arrhythmia/EP. March 5, 2013.

An editorial accompanying the study can be read here:
O'Neill MD. Heart failure, atrial fibrillation, and catheter ablation: Are we there yet?J Am CollCardiol. March 2013.