Outcomes after Endovascular Thrombectomy with or Without Alteplase in Routine Clinical Practice

Importance: The effectiveness and safety of intravenous alteplase given before or concurrently with endovascular thrombectomy (EVT) is uncertain. Randomized clinical trials suggest there is little difference in outcomes but with only modest precision and insufficient power to analyze uncommon outcomes including symptomatic intracranial hemorrhage (sICH). Objective: To determine whether 8 prespecified outcomes are different in patients with acute ischemic stroke treated in routine clinical practice with EVT with alteplase compared with patients treated with EVT alone without alteplase. It was hypothesized that alteplase would be associated with higher risk of sICH. Design, Setting, and Participants: This was an observational cohort study conducted from February 1, 2019, to June 30, 2020, that included adult patients with acute ischemic stroke treated with EVT within 6 hours of time last known well, after excluding patients without information on discharge destination and patients with in-hospital stroke. Participants were recruited from Get With The Guidelines-Stroke, a large nationwide registry of patients with acute ischemic stroke from 555 hospitals in the US. Exposures: Intravenous alteplase or no alteplase. Main Outcomes and Measures: Prespecified outcomes were discharge destination, independent ambulation at discharge, modified Rankin score at discharge, discharge mortality, cerebral reperfusion according to modified Thrombolysis in Cerebral Infarction grade, and sICH. Results: There were 15832 patients treated with EVT (median [IQR] age, 72.0 [61.0-82.0] years; 7932 women [50.1%]); 10548 (66.7%) received alteplase and 5284 (33.4%) did not. Patients treated with alteplase were younger, arrived via Emergency Medical Services sooner, were less likely to have certain comorbidities, including atrial fibrillation, hypertension, and diabetes, but had similar National Institutes of Health Stroke Severity (NIHSS) scores. Compared with patients who did not receive alteplase treatment, patients treated with alteplase were less likely to die (11.1% [1173 of 10548 patients] vs 13.9% [734 of 5284 patients]; adjusted odds ratio [aOR] 0.83; 95% CI, 0.77-0.89; P <.001), more likely to have no major disability based on modified Rankin scale of 2 or less at discharge (28.5% [2415 of 8490 patients] vs 20.7% [894 of 4322 patients]; aOR, 1.36; 95% CI, 1.28-1.45; P <.001), and to have better reperfusion based on modified Thrombolysis in Cerebral Infarction grade 2b or greater (90.9% [8474 of 9318 patients] vs 88.0% [4140 of 4705 patients]; aOR, 1.39; 95% CI, 1.28-1.50; P <.001). However, alteplase treatment was associated with higher risk of sICH (6.5% [685 of 10530 patients] vs 5.3% [279 of 5249 patients]; OR, 1.28; 95% CI, 1.16-1.42; P <.001). Conclusions and Relevance: In this observational cohort study of patients treated with EVT, intravenous alteplase treatment was associated with better in-hospital survival and functional outcomes but higher sICH risk after adjusting for other covariates.