Catheter ablation was associated with significantly fewer deaths and hospitalizations for worsening heart failure than medical therapy in a randomized trial of patients with atrial fibrillation (AFib) and heart failure.
All patients enrolled in the trial either refused to take antiarrhythmic drugs or didn’t benefit from them, had left ventricular ejection fraction (LVEF) of 35 percent or less and an implanted defibrillator.
They were randomized to undergo either catheter ablation (179 patients) or medical therapy in the form of rate or rhythm control (184 patients).
Over a median follow-up of 37.8 months, 24 patients died in the ablation group versus 46 in the medical therapy group, Nassir F. Marrouche, MD, and colleagues reported in the New England Journal of Medicine. That difference was largely driven by a 51 percent reduction in deaths from cardiovascular causes (20 vs. 41).
In addition, patients in the ablation group were 44 percent less likely to be hospitalized for worsening heart failure and saw greater gains in LVEF and a six-minute walk test.
The authors pointed out most previous studies of catheter ablation have focused on soft endpoints like LVEF, quality of life and six-minute walk distance whereas their trial also evaluated the hard, objective outcomes of death and hospitalizations.
In a related editorial, Mark S. Link, MD, said the study is a strong endorsement for ablation, despite its limitations.
“These findings must be interpreted conservatively given the relatively small sample size, specific criteria for patient selection, lack of blinded randomization and treatment allocation, and the fact that the procedures were performed by experienced operators in high-volume medical centers, a circumstance that probably reduced complication rates,” wrote Link, the director of cardiac electrophysiology at UT Southwestern Medical Center in Dallas.
“Despite these limitations, this trial builds on and adds to the accumulating evidence that the use of ablation to maintain normal sinus rhythm in patients with atrial fibrillation and congestive heart failure not only results in fewer admissions for heart failure and decreased mortality but also leads to reverse remodeling, as indicated by an improvement in LVEF.”
Link said it was important to note ablation didn’t completely eliminate AFib in the study’s patients. But their time spent in AFib was about 25 percent, while those in the medical therapy group experienced AFib 60 percent of the time.
Even if AFib isn’t totally “cured,” Link noted, “a reduction in the amount of time in atrial fibrillation may be sufficient for clinical benefit.”
“Longer-duration normal sinus rhythm may improve outcomes by means of a number of mechanisms, including better average rate control, regularity, and greater atrial emptying, all of which translate into improved cardiac output,” he wrote.
“… If a reduction in the density of atrial fibrillation to 25 percent improves outcomes in this trial, what could be accomplished with reductions to 5 percent or even with elimination? All that is for the future. For the present, it seems reasonable to be more aggressive in offering ablation for atrial fibrillation in patients who also have congestive heart failure.”