The implications of catheter ablation for solitary atrial flutter in preventing stroke risk: A nationwide population-based cohort study

Aims: The implications of ablation for atrial fibrillation in preventing stroke are controversial, and no studies have investigated whether ablation prevents ischaemic stroke (IS) in atrial flutter (AFL). Methods and results: This study analysed data contained in the Taiwan National Health Insurance Research Database for 16 765 patients with a first diagnosis of solitary AFL during 2001-2013. Eligible patients were divided into two groups according to whether or not they had received ablation. Propensity score matching (PSM) was performed to mitigate the effects of potential confounding factors. The primary outcome was occurrence of IS during follow-up. After 1:2 PSM, the analysis included 1037 patients in the ablation group and 2074 patients in the non-Ablation group. The incidence of IS was lower in the ablation group compared to the non-Ablation group [subdistribution hazard ratio (SHR) 0.61, 95% confidence interval (CI) 0.41-0.90] during the 2-year follow-up period but not thereafter (SHR 1.03, 95% CI 0.72-1.48). When grouping by stroke history, it revealed that ablation affected the incidence of stroke in patients without history of stroke (SHR 0.59, 95% CI 0.38-0.91) but not in patients with history of stroke. When each group was stratified by CHA2DS2-VASc score, ablation lowered the incidence of stroke in patients with CHA2DS2-VASc ≤3 (SHR 0.31, 95% CI 0.16-0.60) but not in patients with CHA2DS2-VASc ≥4 in the initial 2-year follow-up. Conclusion: The different incidence of IS in patients with/without ablation indicates that ablation reduces the risk of IS in AFL patients.