Intravenous thrombolysis use before interhospital transfer for thrombectomy: a systematic review and meta-analysis.

aimsIntravenous thrombolysis (IVT) before interhospital transfer for endovascular thrombectomy (EVT) in patients with large-vessel occlusion acute ischemic stroke (LVO-AIS) remains controversial. We aimed to evaluate the efficacy and safety of pre-transfer IVT in LVO-AIS patients who presented to primary stroke centers (PSCs) and required transfer to comprehensive stroke centers (CSCs) for EVT.

methodsWe systematically searched PubMed, Embase, and ClinicalTrials.gov from inception to July 2, 2026. Studies comparing IVT versus no IVT prior to interhospital transfer for EVT in patients with LVO-AIS were included. Efficacy outcomes included the primary outcome of excellent functional outcome (modified Rankin Scale [mRS] 0-1 at 90 days), as well as secondary efficacy outcomes including good functional outcome (mRS 0-2 at 90 days), interhospital recanalization, and poor functional outcome (mRS 5-6). Safety outcomes included 90-day mortality, symptomatic intracranial hemorrhage (sICH), any intracranial hemorrhage (ICH), and parenchymal hematoma (PH). Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models, and adjusted estimates were synthesized using the generic inverse variance method.

resultsSixteen observational studies were included. Pre-transfer IVT was associated with significantly higher rates of excellent functional outcome (OR 1.72, 95% CI 1.47-2.01, p<0.00001), good functional outcome (OR 1.64, 95% CI 1.35-1.99, p<0.00001), and interhospital recanalization (OR 7.71, 95% CI 4.08-14.55, p<0.00001), as well as significantly lower risks of poor functional outcome (OR 0.65, 95% CI 0.54-0.79, p<0.0001) and 90-day mortality (OR 0.69, 95% CI 0.59-0.81, p<0.00001). No significant differences were observed between groups in the risks of sICH (OR 0.75, 95% CI 0.50-1.11, p=0.15), any ICH (OR 0.91, 95% CI 0.76-1.09, p=0.31), or PH (OR 1.43, 95% CI 0.88-2.33, p=0.15). In the adjusted analyses, the associations remained significant for excellent functional outcome (aOR 1.47, 95% CI 1.19-1.81, p=0.0004), good functional outcome (aOR 1.61, 95% CI 1.25-2.07, p=0.0002), interhospital recanalization (aOR 8.06, 95% CI 4.71-13.82, p<0.00001), and 90-day mortality (aOR 0.64, 95% CI 0.49-0.84, p=0.001). The magnitude and direction of associations were generally consistent with the unadjusted analyses.

conclusionAmong LVO-AIS patients requiring interhospital transfer from PSCs to CSCs for EVT, pre-transfer IVT was associated with improved functional outcomes and interhospital recanalization, without increasing hemorrhagic risk. These findings support pre-transfer IVT as an effective reperfusion strategy in resource‑limited settings where timely EVT is not immediately accessible.