NEW YORK (Reuters Health) – When paroxysmal atrial fibrillation has not responded to at least one antiarrhythmic agent, radiofrequency catheter ablation is more effective at preventing further episodes compared to therapy with another antiarrhythmic drug, new research shows.

Findings from recent studies have supported catheter ablation as an alternative to drug therapy for atrial fibrillation. However, “these investigations were characterized by small study populations, variable entry criteria and definitions of success, and were conducted in a single or limited number of centers,” lead author Dr. David J. Wilber, from Loyola University Medical Center, Maywood, Illinois, and colleagues note.

In their multicenter study, Dr. Wilber’s team assessed treatment failure rates in 167 patients who were randomized to receive catheter ablation or therapy with a previously unused antiarrhythmic drug. All of the subjects had experienced at least three atrial fibrillation episodes within 6 months prior to randomization.

The main endpoint was treatment failure, defined primarily as documented symptomatic paroxysmal atrial fibrillation occurring during 9 months of follow-up, according to the report in the Journal of the American Medical Association for January 27.

By 9 months, 66% of catheter ablation patients had not experienced a treatment failure compared with just 16% of drug therapy patients. This translates into a 70% reduced risk of treatment failure with use of catheter ablation (p < 0.001). At 30 days, major treatment-related adverse events were less common in the catheter ablation group: 4.9% vs. 8.8% (p < 0.001). Adverse events in the ablation group included pericardial effusion, pulmonary edema, pneumonia, vascular complication, and heart failure, while those in the drug therapy group included life-threatening arrhythmias and drug intolerance requiring treatment discontinuation. At the 3-month assessment, ablation patients had greater improvement in Short Form 36 quality of life scores than did drug therapy patients, and this benefit was sustained through the end of the study. “These findings argue for early use of catheter ablation therapy in patients with paroxysmal atrial fibrillation unresponsive to initial attempts with pharmacologic control,” the authors conclude. Reference:
JAMA 2010;303:333-340.