Risk of stroke in hemodialysis patients with new-onset atrial fibrillation

Background Patients undergoing maintenance hemodialysis are at increased risk of both atrial fibrillation (AF) and stroke. However, the clinical impact of newly diagnosed AF on stroke incidence in this population remains unclear. Objective To compare the risk of stroke between hemodialysis patients with and without new-onset AF, and to estimate the annual stroke risk following AF onset according to CHADS2-VASc score. Methods We analyzed nationwide Korean health insurance claims data, identifying 156,087 adult patients who initiated maintenance hemodialysis between January 1, 2012 and December 31, 2022. Among them, 2,731 patients developed new-onset AF after dialysis initiation, while 133,061 remained without AF. A 3-month landmark analysis was applied to minimize early event bias. We performed 1:1 propensity score matching (PSM) using the greedy method with caliper 0.1, resulting in two well-balanced cohorts of 2,731 patients each. Stroke incidence was compared between groups, and the annualized stroke risk after new-onset AF was stratified by CHADS2-VASc score. Results Patients with new-onset AF had a significantly higher risk of stroke compared to those without AF after PSM (P < 0.0001). The overall annual stroke risk among AF patients was 6.0%, and this risk increased progressively with higher CHADS2-VASc scores, ranging from 0% (score 0) to 16.0% (score 8). The adjusted hazard ratios increased from reference (score 1) to 182.372 (score 8, P<0.0001). Conclusion In patients undergoing hemodialysis, new-onset atrial fibrillation is associated with a significantly increased risk of stroke. Stroke risk rises in proportion to the CHADS2-VASc score, underscoring the importance of individualized risk assessment and preventive strategies in this high-risk population.