Abstract Body (Do not enter title and authors here): Background:
Although observational studies have shown a higher rate of atrial arrhythmia recurrences in patients with atrial fibrillation (AF) undergoing delayed catheter ablation as compared with early ablation, a recent randomized controlled trial (RCT) did not show any such difference. We aimed to perform an updated meta-analysis of the available studies.

Methods:
Multiple online databases were searched for studies comparing early ablation (< 1 year) to delayed ablation (> 1 year) in patients diagnosed with AF. The outcome of interest was atrial arrhythmia recurrence at the longest follow up available. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model.

Results:
A total of 8 studies (1 RCT and 7 observational) with 5,171 patients (early ablation n=1,636, delayed ablation n=3,535) were included. Around 70% patients were men, mean age was 61 years and mean duration of follow up was 28 months. Patients with AF undergoing early catheter ablation had a lower rate of atrial arrhythmia recurrence when compared with the delayed ablation group (OR 0.57, 95% CI 0.44 to 0.73, p < 0.0001). Substantial level of heterogeneity was present between the studies (I2 = 67%).

Conclusion:
Performing catheter ablation early (within 1 year of diagnosis) in patients with AF may lead to significant reduction in atrial arrhythmia recurrence as compared with delayed ablation. The results of this meta-analysis, however, are subject to potential bias and heterogeneity.