Abstract WP009: Impact of Prior Antiplatelet Therapy on Outcomes Following Endovascular Thrombectomy in Acute Ischemic Stroke: An Updated Systematic Review and Meta-Analysis

Background: Endovascular treatment (EVT) has become a well-established treatment approach for carefully selected ischemic stroke patients and can significantly improve the clinical outcomes. However, around 50% of patients do not attain functional independence after treatment. Several predictor factors of EVT outcomes have been identified in previous studies, among which pre-stroke antiplatelet therapy has always been an important area for research. Methodology: A comprehensive electronic search was conducted through the major four medical libraries of PubMed, Cochrane, Scopus, and Web of Science till April 7 th , 2025. Studies were included if they involved adults ≥18 years with ischemic stroke, with a history of prior antiplatelet use status, and evaluated endovascular treatment outcomes. Our primary outcomes are symptomatic intracranial hemorrhage and functional independence (modified Rankin Scale score of 0-2). Statistical analysis was performed using the R meta package, calculating pooled odds ratios (OR) with 95% confidence interval (CI). Heterogeneity was assessed using the inconsistency index, and study quality was evaluated with the ROBINS-I tool. Details of the screening process are presented in the PRISMA flow diagram, (Figure 1). Results: Sixteen studies, involving a total of 50,400 participants were analyzed. Our meta-analysis revealed a slightly higher risk of symptomatic intracerebral hemorrhage (sICH) in patients with prior antiplatelet therapy (APT) (OR = 1.15, 95% CI 1.01, 1.30, P = 0.03) as well as in successful recanalization (OR = 1.13, 95% CI 1.02, 1.25, P = 0.02). In contrast, there was no significant difference in mortality between the two groups (OR = 1.07, 95% CI 0.78, 1.47, P = 0.68), nor in achieving functional independence (mRS 0-2) (OR = 0.72, 95% CI 0.50, 1.03, P = 0.07), (Figure 2). Conclusion: Prior antiplatelet therapy appears to improve recanalization rates but may increase the risk of sICH, particularly with bridging therapy. Its effects on mortality and functional independence remain uncertain. These findings highlight the need for further research studies to robustly define this relationship and explore novel antiplatelets for establishing better substitutes.