Abstract
BACKGROUND: Intravenous thrombolysis (IVT) and endovascular therapy (EVT) are both important treatments for large-vessel occlusion stroke. However, it is still unclear how the timing of IVT, EVT, and the need for transfer of a patient to an endovascular stroke center for EVT affect outcomes. In this investigation, we study the interaction between IVT, rapidity to EVT, and need for transfer among patients with large-vessel occlusion stroke. METHODS: This investigation is an analysis of the OPUS-REACH (Optimizing the Use Prehospital Stroke Systems of Care-Reacting to Changing Paradigms) registry of patients with large-vessel occlusion stroke from 9 endovascular centers in the United States. Using the database, we extracted baseline characteristics of patients, whether the patient received IVT, and time intervals in the patients' care. Patient demographics and characteristics were compared between 2 groups using the χ(2) test for categorical variables and 2-sample t-tests or Wilcoxon rank-sum tests for continuous variables. Multivariable logistic regression was performed to determine the adjusted associations of the variables with 90-day dichotomized modified Rankin Scale outcome. RESULTS: A total of 1171 patients were included in the final analysis, and 38.9% had good functional outcome at 90 days. Male sex and lower initial National Institutes of Health Stroke Scale score were nonmodifiable factors associated with good clinical outcomes. We saw no differences in outcome whether a patient underwent primary or secondary transport. On multiple variable analysis, the receipt of IVT was the only modifiable factor associated with good outcomes. We found no overall effect of time from last known well to EVT on 90-day outcomes unless the patient received IVT. CONCLUSIONS: In this investigation, receipt of IVT was independently associated with improved outcomes at 90 days with an odds ratio of 1.51. Neither shorter time from last known well to EVT nor direct transport to an endovascular stroke center versus transfer to an endovascular stroke center was associated with improved outcomes. We therefore conclude that prehospital algorithms must account for the timely administration of IVT over time to EVT.