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

BackgroundThe 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.MethodsFollowing 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.ResultsEarly 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.ConclusionEarly anticoagulation appears to reduce ischemic recurrence without significantly increasing major hemorrhagic events, but randomized trials are needed to define optimal OAC timing.