Abstract P8: IV Alteplase Prior to Thrombectomy Benefitted Patients With M1 Occlusions but Not Thrombectomy Patients With M2 Occlusions

Abstract

Introduction: Endovascular Therapy (EVT) has overwhelming efficacy for the treatment of acute ischemic stroke due to large vessel occlusion. There is debate regarding whether the administration of IV-alteplase influences the efficacy of this powerful treatment. Here we examined whether M1 and M2 occlusion patients may have differential benefit from IV tPA prior to their EVT. Methods: Data from the Providence System Stroke Registry for acute ischemic stroke patients receiving EVT between January 2015 and May 2020 and who had an occlusion in M1 or M2 middle cerebral artery were used. Multinomial regressions were used to asses if EVT patients with an M1 or M2 occlusion who received IV tPA compared to those who did not were more likely to be discharged as expired or hospice or other location (acute care or long term care, skilled nursing facility, left against medical advice), compared to home or inpatient rehabilitation (IRF), adjusting for patient age, sex, race and ethnicity, last known well to arrival, and NIHSS at admit. Adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) are reported. Results: A total of 667 EVT patients with an M1 occlusion were included in the analysis, of which 52.2% (n=348) received IV tPA and 47.8 (n=319) did not, and 273 EVT patients with an M2 were analyzed, of which 53.8% (n=147) received IV tPA and 46.2% (n=126) did not. The M1 MCA patients treated with IV tPA had 36% lower likelihood of being discharged somewhere other than home / IRF (AOR=0.64, 95% CI: 0.43, 0.94) than to home/IRF. Among M2 patients there were no differences found in the likelihood of being discharged expired/hospice or somewhere other home compared to home/IRF between those who did or did not receive IV tPA. Conclusions: Patients with M1 occlusions who received EVT and IV tPA had better discharge dispositions than those who did not receive IV tPA. However, patients with M2 occlusions who received EVT had equivalent discharge dispositions regardless of whether they got IV tPA or not. These results underscore the need for more randomized prospective clinical trials to evaluate the impact of thrombolysis on EVT patient outcomes and highlight the importance of evaluating lesion location as a potential covariate in these trials.