Randomization of Endovascular Treatment with Stent-Retriever and/or Thromboaspiration versus Best Medical Therapy in Acute Ischemic Stroke Due to Large Vessel Occlusion in the Extended Time Window Trial (RESILIENT-Extend): Rationale and Design

BACKGROUND: Randomized trials have demonstrated substantial benefit of mechanical-thrombectomy (MT) in selected patients treated 6 to 24 hours after stroke onset. However, these trials relied on advanced imaging not typically available in resource-constrained settings. The RESILIENT-Extend trial aims to evaluate the efficacy and safety of MT in the 8-24-hour window using a pragmatic imaging selection based on non-contrast CT and CT angiography alone. METHODS: RESILIENT-Extend is a multicenter, randomized, controlled, open-label, blinded-endpoint phase III trial conducted in Brazil. Patients presenting with anterior circulation LVO within 8-24 hours from time last known well will be randomized 1:1 to receive either MT plus best medical management (BMM) or BMM alone. The trial uses a minimization algorithm to balance prognostic variables including age, NIHSS, ASPECTS, occlusion site, time window, and clinical site. The primary outcome is the distribution of 90-day modified Rankin Scale scores assessed by blinded central adjudication. DISCUSSION: RESILIENT-Extend is the first randomized trial to assess MT in the extended time window using only widely available imaging modalities. The results will inform the generalizability of MT to real-world practice in low- and middle-income countries and resource-constrained settings. CLINICALTRIALS: govNCT04256096.