First-Line AF Ablation Cuts Risk of Progression vs Drug Therapy

CHICAGO – Early ablation of atrial fibrillation (AFib) reduces the risk of progression, compared with antiarrhythmic therapies, according to results of a multicenter, randomized trial called PROGRESSIVE-AF.

Over 36 months of follow-up, the trial linked early ablation with a reduced risk of persistent AFib (1.9% vs. 7.4%), and in addition, those in the ablation group were less likely to have recurrent atrial tachyarrhythmias of any kind (56.5% vs. 77.2%), reported Jason G. Andrade, MD, at the American Heart Association scientific sessions.

Serving as a long-term extension of the EARLY-AF trial published almost 2 years ago, this trial expands evidence that progressive AFib can be attenuated, a concept that has been debated.

“Can early AFib ablation stop progression?” asked Carina Blomström-Lindqvist, MD, PhD. The invited discussant for the PROGRESSION-AF trial, Blomström-Lundqvist concluded, “here is another set of data that suggests it can.”

By another set of data, Blomström-Lindqvist was referring to a previously published multinational study called ATTEST In this study, which involved 29 sites worldwide and compared radiofrequency ablation to antiarrhythmic drug therapy, early ablation also produced a lower risk of persistent AFib at the end of 3 years (2.4% vs. 17.5%; P = .0009).

In the previously published open-label EARLY-AF trial, 303 patients with paroxysmal, untreated AFib were randomized to cryoballoon ablation or antiarrhythmic drugs. The primary endpoint was the first documented recurrence of an atrial tachyarrhythmia between 91 and 365 days. The lower rate following ablation (42.9% vs. 67.8%) represented a more than 50% reduction in risk (hazard ratio, 0.48; P < .001) relative to antiarrhythmic therapy.

In PROGRESSIVE-AF, the same 303 patients were monitored continuously for an additional 24 months with an implanted cardiac monitor programmed with an AFib-detection algorithm. The data from the monitor were obtained daily. Over the final 2 years of the study, office visits were conducted every 6 months.

Tachyarrhythmias Represent Primary Endpoint

In addition to persistent AFib, defined as lasting ≥ 7 days or lasting 48 hours to 7 days but requiring cardioversion for termination, patients in PROGRESSIVE-AF were also monitored for recurrent atrial tachyarrhythmias, AFib burden, quality of life (QOL), and health care utilization, and safety.

The average age was roughly 58 years. Although more than one-third had hypertension, most had no other comorbidities. The authors emphasized that the study population overall was relatively young and healthy.

Those randomized to antiarrhythmic therapy in EARLY-AF/PROGRESSIVE-AF received commonly prescribed therapies titrated to maximally tolerated doses using standardized protocols. At the start of EARLY-AF, flecainide, taken by 65% of patients, was the most commonly used agent, followed by sotalol, propafenone, dronedarone, and amiodarone.

At the end of PROGRESSIVE-AF, the order of the most common therapies did not change relative to EARLY-AF, but only 49% of patients were taking flecainide and 31% were no longer taking any antiarrhythmic therapy.

At the end of 3 years of follow-up in EARLY-AF/PROGRESSIVE-AF, the difference in persistent AFib represented a 75% reduction in favor of early ablation (HR, 0.25; 95% confidence interval, 0.09-0.70).

In those treated with ablation relative to those treated with antiarrhythmic therapy, the lower rate of atrial tachyarrhythmia lasting more than 7 days (1.9% vs. 6.0%) represented a 70% risk reduction (HR, 0.30; 95% CI 0.10-0.93). The protection from cardioversion for atrial tachyarrhythmia lasting between 2 and 7 days in duration (0.6% vs. 4.7%) translated into an 86% relative reduction (HR, 0.14; 95% CI, 0.02-0.85).

The impact on QOL for those randomized to ablation, which was measured with both AFib-specific and generic measures, was meaningful to patients, according to Andrade, director of the Cardiac Electrophysiology Laboratory, Vancouver General Hospital.

For example, the mean difference in the AF Quality of Life Survey (AFEQT), was 8.0 at 1 year and 7.4 at 3 years in favor of ablation. A change of 5 points in this score is considered to be a clinically meaningful difference, according to Andrade.

Numerically, the relative risk of emergency room visits and cardioversion were lower in the ablation group, but the differences did not reach statistical significance. However, the lower hazard ratio for hospitalization was significant (HR, 0.31; 95% CI, 0.15-0.66), supporting a reduction in consumption of health care resources.

Ablation Found Safer Than Drugs

The rate of adverse events of any kind (11.0% vs. 23.5%) and serious adverse events (4.5% vs. 10.1%) were lower in the ablation group.

There were no differences in major adverse cardiovascular events observed in this period of follow-up, but Andrade pointed out that follow-up was not long enough to expect differences in these events.

Impressed by the magnitude of the reduction in persistent AFib in a population of relatively young and healthy patients considered to be at a low risk of AFib progression, Blomström-Lindqvist, a professor of cardiology at the Institution of Medical Science, Uppsala, Sweden, indicated that the data support early ablation as a means to reduce risk of this outcome.

However, she did caution that progressive AFib was observed in a relatively small proportion of patients managed with antiarrhythmic therapy at 3 years, an outcome relevant when discussing treatment options with patients.

The results were published in New England Journal of Medicine simultaneously with Andrade’s presentation.

Andrade reports financial relationships with Bayer, Bayliss, Biosense, Bristol-Myers Squibb, Medtronic and Servier. The trial, funded largely by the Canadian government and Canadian professional societies, received additional funding from Bayliss and Medtronic. Blomström-Lundqvist reports financial relationships with Bayer, Boston Scientific, Cathprint, Medtronic, and Sanofi.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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