Radiofrequency catheter ablation of accessory pathways. Outcome and use of antiarrhythmic drugs during follow-up.

Aims: The purpose of this study was to assess the acute and long-term success of accessory pathway ablation in a single large-volume centre, concentrating on long-term recurrences and the clinical use of antiarrhythmic drugs.

Methods And Results: A total of 519 consecutive patients (mean age 40+/-14 years) underwent radiofrequency ablation of manifest or concealed accessory pathways. The patients were seen in the hospital or by the referring physician at 6 and 12 months. Long-term follow-up information was obtained by questionnaire. Pathway conduction was abolished in 476 cases (91.7%). 'Redo' procedures, due to recurrence, were performed in 38 patients (7.3%) and were successful in 30 (78.9%). Follow-up data were obtained from 454 patients (87.5%) with a follow-up duration of 22. 6+/-12.4 months. Among the 398 patients with successful ablations who responded to the questionnaire, 340 (85.4%) were asymptomatic with only 10.6% taking antiarrhythmic drugs. An additional 20 patients (5.0%) had symptoms suspicious of recurrence. In total, 66 out of 398 successfully treated patients (16.6%) were taking antiarrhythmic drugs. Twenty-three out of 56 (41.1%) patients with failed ablations were asymptomatic, 12 of whom (21.4% of patients with failed ablations) had not been administered antiarrhythmic drugs. In the total group of 454 patients with ablation attempts and available follow-up data, 99 (21.8%) were still taking antiarrhythmic drugs during follow-up.

Conclusions: Patients with successful ablation of accessory pathways show excellent long-term results. However, 17% of successfully treated patients were still taking antiarrhythmic drugs during the period of long-term follow-up. On the other hand, 21% of patients with failed ablations were symptom-free without antiarrhythmic drugs. On an intention-to-treat basis, 22% of the patients with ablation attempts were still taking antiarrhythmic drugs during follow-up.