Thrombolysis in Patients With Large‐Vessel Occlusion Directly Admitted or Transferred to a Thrombectomy Center: A Population‐Based Study

Abstract

Background Our goal is to evaluate whether the administration of thrombolytic treatment has varying effects on clinical and radiological outcomes in patients with large‐vessel occlusion stroke, based on the type of stroke center where the treatment was given (thrombectomy‐capable center versus local stroke center). Methods We included patients with an acute ischemic large‐vessel occlusion stroke who were directly admitted to thrombectomy‐capable centers and treated with endovascular thrombectomy, or were transferred from local stroke centers as thrombectomy candidates, in Catalonia, Spain, between 2017 and 2021. The primary outcome was the shift analysis on the modified Rankin scale score at 90 days. Secondary outcomes included death at 90 days and the rate of parenchymal hemorrhage and successful reperfusion. Inverse‐probability weighting clustered at the type of stroke center was used to estimate the effects. Results The analysis included 2268 patients directly admitted to thrombectomy‐capable centers, of whom 975 (49%) were treated with thrombolysis, and 938 patients transferred from local stroke centers, of whom 580 (66%) were treated with thrombolysis and 616 (67%) were treated with thrombectomy. Mean age was 72 (SD ±13) years, median National Institute of Health Stroke Scale score was 17 (interquartile range, 12–21), and 1363 patients were women (48%). Patients treated with intravenous thrombolysis were younger, had shorter time from onset to first image, higher Alberta Stroke Program Early Computed Tomography Score, and lower rates of wake‐up stroke, atrial fibrillation, and anticoagulation intake. Patients treated with thrombolysis had better functional outcome at 90 days, with no difference between patients directly admitted to thrombectomy‐capable centers (adjusted common odds ratio [acOR], 1.50 [95% CI, 1.24–1.81]) and patients transferred from local stroke centers (acOR, 1.44 [95% CI, 1.04–2.01]). Patients treated with intravenous thrombolysis had lower death rate, higher rate of parenchymal hematoma, and similar rate of successful reperfusion, with no difference according to type of center ( P interaction >0.1). Conclusion Administration of intravenous thrombolysis in patients with a large‐vessel stroke with intention of thrombectomy was associated with lower degrees of disability, lower death rate, and higher rates of parenchymal hematoma both in thrombectomy‐capable centers and in local stroke centers.