Intravenous Thrombolysis Use before Inter‐Facility Transfer for Thrombectomy: Association with Efficacy and Safety Outcomes

Objective Patients with acute ischemic stroke and large vessel occlusion (LVO) often require transfer from primary stroke centers (PSCs) to thrombectomy‐capable centers. This study assessed the efficacy and safety of intravenous thrombolysis (IVT) initiated before inter‐hospital transfer. Methods Data from 2 prospective cohorts of patients with anterior circulation LVO transferred for thrombectomy from a PSC, regardless of whether thrombectomy was eventually attempted at the endovascular‐capable center, were analyzed. Efficacy outcomes included good 3‐month functional outcome (modified Rankin scale [mRS] = 0–2), excellent functional outcome (mRS = 0–1), and arterial recanalization during transfer. Safety outcomes included any intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) at 24 hours. Propensity score with overlap weighting balanced the covariates between patients treated with IVT versus those without. Results Of 521 patients, 260 (50%) received IVT before transfer. IVT was withheld mainly due to being outside the 4.5‐hour window (58%) or anticoagulant use (21%). Median age was 72 years, 55% were men, and median baseline National Institutes of Health Stroke Scale (NIHSS) was 15. After propensity score with overlap weighting, patients receiving IVT more frequently had good functional outcome (odds ratio [OR] = 2.17, 95% confidence interval [CI] = 1.43–3.30, p < 0.01), excellent functional outcome (OR = 1.99, 95% CI = 1.21–3.25, p < 0.01), and inter‐facility recanalization (OR = 5.64, 95% CI = 2.92–10.89, p < 0.01) compared with patients not treated with IVT. Any ICH (OR = 1.14, 95% CI = 0.76–1.70) and sICH (OR = 0.73, 95% CI = 0.36–1.51) rates were similar between groups. Interpretation IVT before transfer was associated with improved recanalization and functional outcomes without increasing safety risks but is used in only 50% of patients. Expanding IVT criteria, including treatment beyond 4.5 hours and in anticoagulated patients, should be explored. ANN NEUROL 2025