The risk and timing of acute ischemic stroke after electrical cardioversion for atrial fibrillation in Taiwan: A nationwide population-based cohort study

Background: There is a positive association between electrical cardioversion (ECV) and acute ischemic stroke (AIS). Although 4 weeks of anticoagulation therapy after ECV in atrial fibrillation (AF) patients is generally suggested by current guidelines to reduce the risk of AIS, limited studies have been conducted in Asian populations to determine the risk and timing of AIS after ECV for AF in recent years. Therefore, we aim to use the National Health Insurance Research Database (NHIRD) in Taiwan to determine the risk and timing of AIS after ECV for AF. Methods: The data analyzed in this nationwide population-based retrospective cohort study were obtained from the NHIRD in Taiwan. The outcome in this study was the cumulative incidence of AIS in patients with AF during 7-day and 30-day follow-up periods after the patients underwent ECV. Results: Our analysis included 39,697 patients with AF, of whom 5723 received ECV and 5723 were propensity score-matched controls. Compared to the controls, patients who received ECV exhibited a significantly increased incidence of 7-day AIS development (adjusted hazard ratio [HR] = 1.524, p = 0.003). In contrast, the incidence of 30-day AIS development showed no significant increase (adjusted HR = 1.301, p = 0.426). Conclusions: AF patients who underwent ECV had a higher incidence of 7-day AIS development but not 30-day AIS development. Considering the timing of AIS development after ECV in AF patients, the optimal duration of antithrombotic therapy after ECV deserves further investigation.