NEW YORK (Reuters Health) – Patients with atrial fibrillation undergoing pulmonary vein isolation by radiofrequency catheter ablation are less likely to have immediate recurrence of AF if they’re given a short course of corticosteroids after the procedure, a Japanese team reports.

Writing in the October 26 issue of the Journal of the American College of Cardiology, Dr. Takashi Koyama and colleagues at the University of Tsukuba, note that pulmonary vein isolation (PVI) is effective for refractory paroxysmal AF, but recurrence rates in the first few weeks are high — up to 65%, according to an editorialist.

On evidence that the recurrence is triggered by inflammatory processes resulting from procedural damage to the myocardium, the researchers conducted a study in 130 consecutive patients undergoing a PVI procedure to see if corticosteroid therapy might be beneficial.

The participants were randomized to receive a 2-mg/kg IV dose of hydrocortisone immediately after the procedure followed by oral prednisone 0.5 mg/kg/day for 3 days, or placebo injection and pills.

The prevalence of AF recurrences within the first 3 days was 7% in the corticosteroid group, significantly lower than in the placebo group (31%; p<0.001), Dr. Koyama and associates report. However, over days 4-30, the rates were comparable in the two groups at 20% and 18%, respectively. There did seem to be a long-range effect. “The AF-free rate at 14 months post-ablation was greater in the corticosteroid group (85%) than in the placebo group (71%, p=0.032),” according to the report. The authors conclude, “Transient use of small amounts of corticosteroids shortly after AF ablation may be effective and safe for preventing not only immediate AF recurrences but also AF recurrences during the mid-term follow-up period after PVI.” In an accompanying editorial, Dr. Bernard Belhassen of Tel Aviv Sourasky Medical Center, Israel notes that recurrent AF after catheter ablation is so common that recurrences within the first 3 months of the procedure are discounted in terms of determining the success or failure of the procedure. “For the patient, however, this period may represent a tumultuous phase during which there may be a need for drug adjustments, hospitalization, or electrical cardioversion,” he writes. While welcoming the study, Dr. Belhassen raises a number of caveats, however. For example, the data did not include information about patients with diabetes, and so safety is uncertain given that corticosteroid therapy raises blood glucose levels. Also, the possible slowing of healing of the ablated tissues with corticosteroid therapy was not addressed. He concludes, “The question of whether the results of the present study should prompt us to include corticosteroid therapy in our routine practice or whether we should wait for confirming studies is difficult to answer.” J Am Coll Cardiol 2010;56:1463-1472.