Abstract Body (Do not enter title and authors here): Background: Atrial fibrillation (AF) is a leading cause of stroke. However, predictors of stroke after AF ablation have not been well clarified, therefore, evidences of anticoagulation therapy after the procedure have been limited. Although left atrial low-voltage areas (LVAs) reflects atrial cardiomyopathy, which is a potential cause of thromboembolism, there are few reports of an association between LVAs and stroke. The purpose of this study was to investigate the association between atrial cardiomyopathy assessed by LVAs and stroke in patients undergoing AF ablation.
Methods: The study design was a single center, retrospective observational study. This study included 1,486 (age, 68 ± 10 years; female, 501 [34%]; persistent AF, 905 [61%]) consecutive patients who underwent initial AF ablation from December 2014 to March 2022. The definition of LVAs were areas with a bipolar voltage of <0.5 mV in the left atrium. The area of LVAs in the whole left atrium was divided into 3 groups, namely <5cm², 5-20 cm² and ≥20 cm². Stroke after AF ablation was followed for 60 months.
Results: Of 1,486 patients, LVAs were found in 352 (24%) patients, and 25 (1.7%) patients developed stroke (hemorrhagic stroke, 4 [16%] patients; ischemic stroke 21 [84%] patients). Freedom from stroke was significantly lower in patients with LVAs than in those without (<5cm²: 98.3%, 5-20 cm²: 95.4%, ≥20 cm²: 88.8%, p<0.001). Additionally, LVAs ≥20 cm² was an independent predictor of the development of stroke after AF ablation (hazard ratio 4.9, 95% confidence interval: 2.0-12; p=0.001, adjusted by estimated glomerular filtration rate and AF recurrence after ablation).
Conclusion: In patients with initial AF ablation, freedom from stroke after AF ablation was significantly lower in patients with LVAs ≥20 cm² than in patients with LVAs 5-20 cm² and in patients with LVAs <5cm². Particularly, LVAs ≥20 cm² was an independent predictor of the development of stroke after AF ablation.