Radiofrequency ablation converts patients with chronic atrial fibrillation to normal rhythm with improved quality of life for at least one year without use of anti-arrhythmic medication, according to an article in the March 2 issue of the New England Journal of Medicine.

Although the treatment has shown promise for several years, the current study, conducted by American and Italian researchers, provides conclusive evidence of catheter ablation’s positive effects on heart rhythm, symptoms, quality of life and cardiac function.

The randomized, controlled trial used long-term automatic daily monitoring of cardiac rhythm to assess efficacy of ablation. The trial enrolled 146 patients, 77 of whom were randomized to receive left atrial catheter ablation procedure known as circumferential pulmonary-vein ablation; the remaining 69 patients were randomized to a control group.

In all, 74 percent of study participants who had the procedure had normal sinus rhythm at one year without need for anti-arrhythmic drugs. They reported a steep drop in severity of symptoms, and the dilated left atria returned to normal size. No side effects were reported, although some of the patients needed a second procedure to fully suppress the atrial fibrillation.

“We have shown objectively, and with rigorous follow-up, that this procedure is a very good option for patients with symptomatic, chronic atrial fibrillation who otherwise may have to live with atrial fibrillation for the rest of their lives,” said lead author Hakan Oral, MD, of the University of Michigan.

The current study was the first ever designed specifically to separate the ablation procedure’s effects from those of medications and cardioversion, which are often used temporarily after ablation.

All study participants took amiodarone for six weeks before and three months after they were randomized to either the ablation group or the control group. Ablation patients were allowed to have a cardioversion during their ablation procedure and as needed in the first three months after the procedure, and they were allowed to take amiodarone for up to three months. Control-group patients had a cardioversion after being randomized, and were allowed to have a second one anytime in the next three months. During those three months, they took amiodarone daily, then stopped. If their atrial fibrillation came back, control patients were allowed to resume amiodarone or have an ablation procedure. Of the 69 control patients, 53 chose ablation during the follow-up period.

For a year, all patients used a portable monitor, which transmitted data by phone to a central location. Rhythm data were analyzed by cardiologists who did not know which patients had had ablation. The patients also had several clinic visits, and electrocardiogram and echocardiogram heart tests, during the year, at which they completed questionnaires about the severity of their symptoms.

Although the study was not designed to compare the efficacy of catheter ablation with long-term use of rhythm-regulating medications, only 4 percent of patients who didn’t have ablation and stopped medication after three months were still free of atrial fibrillation after one year.

Senior author Fred Morady, MD, noted that after one year, ablation patients had a decrease in left atrial size and an improvement in ejection fraction. The patients who received ablation reported significant reductions in the severity of their symptoms compared with those who did not receive ablation.

In the ablation group, 20 patients needed one more ablation procedure to address remaining atrial fibrillation, and 4 had a second ablation after developing atrial flutter. There were no complications related to the ablation procedure.