Incidence of Atrial Fibrillation After Atrial Flutter Ablation.

Objectives: This study was conceived to perform a comprehensive systematic review and meta-analysis of the available evidence to compute the incidence of atrial fibrillation (AF) after successful atrial flutter (AFL) catheter ablation, defined by targeting for bidirectional block, using different types of follow-up modalities and durations.

Background: Cavotricuspid-isthmus dependent AFL is usually initiated by short bursts of AF. The incidence of AF after AFL ablation is variable. We evaluated the variation in the reported incidence of AF depending on the type and duration of follow-up, and AF incidence in patients with prior AF versus no prior AF.

Methods: A systematic review and meta-analysis of published studies between January 1996 and April 2015 and abstracts in the last 2 years describing patients who underwent AFL ablation and the subsequent incidence of AF was performed.

Results: Forty-eight studies were included (n = 8,257, ablation success rate: 96%, 79% male). Incidence of new-onset AF correlated with follow-up duration (29% for a weighted mean follow-up duration of 30 months). New-onset AF incidence with <2 years follow-up was 12.4% among group 1 (electrocardiogram and symptoms-driven evaluation, n = 759), 19% for group 2 (outpatient Holter monitoring for 1 day to 7 days/year, n = 315), and 45% for group 3 (>7 days/year Holter monitoring or by implanted cardiac devices, n = 178). Mean follow-up duration was 15.3 months, 18.5 months, and 16.3 months, respectively. In patients with and without prior AF, the incidence for AF after AFL ablation was 35.3% during mean follow-up duration of 29.7 months. In studies with <2 years follow-up duration, AF incidence was 54% in patients with prior AF versus 13.9% without prior AF (odds ratio: 7.43, 95% confidence interval: 4.96 to 11.11; p < 0.00001). In studies with >2 years follow-up duration, AF incidence was 51.3% in patients with prior AF versus 26.2% without prior AF (odds ratio: 2.93, 95% confidence interval: 2.42 to 3.56; p < 0.00001).

Conclusions: The incidence of AF after AFL ablation is high especially in patients with prior AF when compared to those without prior AF. The detection of AF in patients without prior AF significantly increases with more frequent monitoring and/or longer follow-up duration.