Anticoagulation Timing After Stroke in Atrial Fibrillation: Evidence from a Systematic Review and Meta-Analysis

Background The optimal timing for initiating oral anticoagulation (OAC) after acute ischemic stroke in patients with atrial fibrillation (AF) remains a critical clinical dilemma. Early anticoagulation may lower recurrent ischemic stroke risk but could raise hemorrhagic transformation risk, and current guidelines are conflicting. This meta-analysis examined the impact of early versus late initiation of anticoagulation on clinical outcomes—recurrent stroke, intracranial haemorrhage, Bleeding, mortality, transient ischemic attack (TIA), and thrombosis—in AF-related ischemic stroke. Methods Following PRISMA guidelines, we conducted a systematic review and meta-analysis of observational and experimental studies that compared early and late anticoagulation; seventeen studies met inclusion criteria. Results Early anticoagulation was associated with a significantly lower risk of recurrent ischemic stroke (OR = 0.72, 95% CI [0.55-0.96], P = .03). The incidence of intracranial hemorrhage did not differ significantly between groups (OR = 1.13, 95% CI [0.83-1.53], P = .44). No significant differences were observed for Bleeding (OR = 0.87, 95% CI [0.67-1.12], P = .27), mortality (OR = 0.94, 95% CI [0.72-1.24], P = .68), TIA (OR = 0.99, 95% CI [0.57-1.74], P = .98), or thrombosis (OR = 0.87, 95% CI [0.59-1.27], P = .47). Notable heterogeneity—likely due to differences in study design, anticoagulant type, and stroke severity—limits firm conclusions. Conclusion Early anticoagulation appears to reduce ischemic recurrence without significantly increasing major hemorrhagic events, but randomized trials are needed to define optimal OAC timing.