Cardioversion strategy improves ablation outcome
SALT LAKE CITY, UTAH. Early recurrence of atrial tachyarrhythmias (atrial flutter, atrial fibrillation and atrial tachycardia) is common among atrial fibrillation (AF) patients having undergone radiofrequency catheter ablation. Some studies have found that as many as 50% of patients experience recurrence during the first 3 months following their procedure (blanking period), with most recurrences occurring during the first 4 weeks. Evidence regarding the effect of early recurrence on long-term outcome is somewhat conflicting, but a reasonable estimate is that about half of early recurrences will not affect long-term outcome. Of course, knowing which early recurrence will affect long-term outcome and which won't is the $64,000 question.

Electrophysiologists at the University of Utah and the Intermountain Medical Center now suggest that implementing a strategy of prompt cardioversion in the case of recurrence during the 3-month blanking period will markedly improve long-term outcome. Their clinical trial included 1304 patients who underwent a total of 1759 ablations (35% repeat rate). The mean patient age was 65 years, 58% were male, 52.6% had paroxysmal, 26.4% had persistent, and 21% had permanent (long-standing persistent) AF. Following their catheter ablation all patients were instructed to watch for symptoms of arrhythmia recurrence and to take their pulse daily. If the pulse was irregular or exceeded 100 bpm, they were asked to present themselves for evaluation at the hospital the same day or the next business day in a fasting state.

Prompt (within 24 to 48 hours) cardioversion was performed as deemed necessary. A total of 515 cardioversions were performed for occurrence of post-ablation AF or flutter with 65% of procedures being done in patients with persistent or permanent AF. Nearly 50% of recurrences occurred in the first month post-ablation, 64% occurred in the first 90 days, and 24% occurred after a period of 6 months. Eighty percent of afibbers requiring cardioversion during the blanking period needed more than one procedure.

After a year of follow-up, 78% of the patients who had needed cardioversion were in normal sinus rhythm. Overall, 75.6% of patients experiencing arrhythmia within the first 90 days following ablation were in sinus rhythm without the use of antiarrhythmics at the 1-year mark.

The Utah researchers conclude that a strategy of prompt cardioversion in case of arrhythmia recurrence during the first 6 months following catheter ablation markedly improves long-term outcome.

Malasana, G, Bunch, TJ, et al. A strategy of rapid cardioversion minimizes the significance of early recurrent atrial tachyarrhythmias after ablation for atrial fibrillation. Journal of Cardiovascular Electrophysiology, Vol. 22, July 2011, pp. 761-66

Editor's comment: These findings are clearly of great importance and would indicate that prompt cardioversion of atrial arrhythmias occurring within 90 days of a catheter ablation results in a better long-term prognosis. In practical terms this would mean that an afibber who experiences an episode lasting longer than say 2 to 4 hours should promptly present for cardioversion.