Previous Antiplatelet Therapy and Outcomes of Acute Ischemic Stroke With Large Vessel Occlusion Treated With Direct Endovascular Therapy.

Background And Objectives
Previous antiplatelet therapy (APT) may influence outcomes in patients undergoing direct endovascular therapy (EVT) for anterior circulation large vessel occlusion (LVO) stroke, but evidence on clinical benefits and safety is limited and inconsistent. We aimed to evaluate the effects of previous APT on the outcomes of direct EVT.Methods
We conducted a retrospective analysis of consecutive patients treated at 20 high-volume stroke centers across 9 European countries and Israel (EVA-TRISP registry, 2015-2023). We included adults with anterior circulation LVO strokes, without previous use of IV thrombolysis (IVT) or anticoagulants. We compared outcomes of direct EVT patients stratified by previous APT regimen, using propensity score matching based on medical history and multilevel models to address confounders. The primary outcome was the 90-day modified Rankin Scale (mRS) score. The secondary efficacy outcomes were 90-day independence and the rate of successful reperfusion. The secondary safety outcomes were the rate of symptomatic intracranial hemorrhage (sICH) and mortality.Results
Among 12,950 patients, 2,611 met the criteria and 1,308 were matched: 480 without previous APT and 828 with any previous APT, among whom 764 were on single APT and 64 on dual APT. The overall mean age was 75.8 ± 11.4 years, and 49.4% were female; the mean NIH Stroke Scale score was 13.1 ± 7.2 points, the successful reperfusion rate was 74.7%, and the median mRS score was 3 (interquartile range 2-4), with 38.8% of patients independent at 90 days. When compared with no previous APT, any previous APT was associated with a shift toward lower mRS scores at 90 days (odds ratio [OR] 1.30, CI 1.04-1.61, p = 0.018). Independence at 90 days was associated with any previous APT (OR 1.62, CI 1.22-2.16, p = 0.001). Any previous APT was not associated with successful reperfusion (OR 0.96, CI 0.69-1.35, p = 0.821), sICH (OR 1.06, CI 0.47-2.39, p = 0.880), or mortality (OR 0.89, CI 0.66-1.21, p = 0.821). There was no significant interaction between any previous APT and proximal/distal occlusion location (p = 0.213) or time-to-groin earlier/later than 6 hours (p = 0.743).Discussion
In patients with anterior circulation LVO stroke treated with direct EVT and no previous anticoagulation, pretreatment with any APT was independently linked to better 90-day functional outcomes and higher independence, without increasing sICH risk.Classification Of Evidence
This study provides Class III evidence that, in patients with anterior circulation LVO stroke treated with direct EVT, previous APT is associated with better 90-day functional outcomes compared with no previous APT.