New insights into long-term follow-up of atrial fibrillation ablation: full disclosure by an implantable pacemaker device

Abstract

Introduction: Long-term outcome of radiofrequency ablation (RFA) for atrial fibrillation (AF) is difficult to assess. This study sought to evaluate various aspects of very long-term follow-up (FU) by the properties of an implantable device.

Methods: Fourteen patients with an implanted pacemaker device (Medtronic AT500) were selected for RFA, due to drug-refractory and highly symptomatic AF despite antibradycardic pacing.

Results: With a mean FU of 41.4 +/- 15.1 months, we could achieve continuous monitoring for more than 400,000 hours after RFA. Based on symptomatic episodes, simulated 24-hour, 48-hour, or 7-day Holter, 57% to 71% of the patients were classified as RFA responders. With permanent FU provided by the implanted device, 43% of the patients exhibited a positive treatment effect and only 21% had no tachyarrhythmic episode at all in long-term FU. With a mean of 1.7 +/- 0.7 RFA per subject, atrial tachyarrhythmia burden (ATB) was significantly reduced from a median of 3.6 to 0.3 hours per day (P < 0.001). Two out of 14 patients developed AF recurrences after a tachyarrhythmia-free period of more than 12 months.

Conclusion: Continuous monitoring provided by an implantable device is able to detect significantly more AF episodes than routine FU. ATB is decreased significantly by (repeated) RFA over a very long-term FU. AF may reoccur very late after long-lasting (>1 year) episode-free intervals. A subgroup of patients with drug-aggravated bradycardia in brady-tachy syndrome might be considered for PV isolation rather than pacemaker implantation.