ABSTRACT NUMBER: ESOC2026LT51 LT51 - PLATELET FUNCTION GUIDED ANTIPLATELET THERAPY FOR ACUTE ISCHAEMIC STROKE: A RANDOMISED CONTROLLED TRIAL

Abstract Background and aims High on-treatment platelet reactivity (HOPR), which indicates non-responsiveness or resistance to aspirin or clopidogrel, is common in patients with a history of cardiovascular disease and may reduce the benefits of antiplatelet therapy for secondary prevention. Whether switching antiplatelet therapy according to platelet function testing (PFT) is safe and effective is uncertain. Methods In this multicentre, randomised, open-label trial with blinded endpoint adjudication, adults 1–3 months after first-ever non-cardiogenic ischaemic stroke receiving aspirin were randomly assigned (1:1) to a PFT-guided antiplatelet strategy or standard aspirin therapy. In the guided group, patients with HOPR (maximal aggregation rate ≥35%) switched antiplatelet therapy. The primary outcome was HOPR at 30 ± 5 days; the prespecified secondary outcome was major ischaemic events within 180 days. Safety outcomes were serious adverse events and Major bleeding within 180 days. Analyses were by intention to treat. Results 1224 patients (mean age 63±9.8 y, 34·1%female) were included with 611 allocated to the platelet function testing and 613 to standard therapy. HOPR occurred in 93 (15·2%) of 611 patients in the guided group and 129 (21·0%) of 613 patients in the standard group (adjusted relative risk 0·72, 95% CI 0·57–0·92; p=0·008). Major bleeding occurred in five (0·8%) and four (0·7%) patients (p=0·778), and serious adverse events occurred in 21 and 12 patients, respectively (p=0·132). Conclusions Platelet function guided antiplatelet switching reduced the rate of high platelet reactivity without any excess of major bleeding or serious adverse events. Conflict of interest