Abstract P10: Posterior Circulation Strokes Are Less Likely to Receive Alteplase or Mechanical Thrombectomy: Analysis From the IAC Study

Abstract

Background: Emergent treatment with intravenous thrombolysis and mechanical thrombectomy improved outcomes in patients with acute ischemic stroke. We aim to identify differences in acute stroke treatment trends between strokes occurring in the anterior versus posterior circulation. Methods: The IAC (Initiation of Anticoagulation after Cardioembolic stroke) study represents pooled data registry of 8 comprehensive stroke centers across the United States and included patients with cardioembolic stroke in the setting of AFib. In a post hoc analysis, we identified and separated patients into posterior circulation stroke (PCS) and anterior circulation stroke (ACS) groups based on imaging. Patients without infarct locations or those with multi-circulation infarcts were excluded. We compared baseline characteristics, stroke severity and the treatment trends with alteplase (tPA) and mechanical thrombectomy (MT) in PCS vs ACS using Fisher exact test, t-test and non-parametric tests. We then performed multivariable logistic regression adjusted for baseline differences to determine the associations between PCS and tPA or MT. Results: Of the 2084 patients in IAC cohort, 1589 met inclusion criteria for this study, in which 294 (22.7%) had PCS. Mean age was 76.8 years, 29.3% received tPA and 26.9% had MT. When compared to ACS, patients with PCS were more likely to be men (55.4% vs 45.6%, p=0.003), have diabetes (42.8% vs 29.8, p< 0.001) and lower median NIHSS score on admission (4 vs 8, p<0.001). Patients with PCS were less likely to receive tPA (16.3% vs 32.3%, p<0.001) or MT (10.9% vs 30.6%, p<0.001). Other variables were not significantly different. When adjusted for baseline differences, patients with PCS remained less likely to be treated with tPA (adjusted OR 0.49, 95%CI 0.35-0.70, p<0.001) or MT (adjusted OR 0.38, 95%CI 0.25-0.58, p<0.001). Conclusion: Posterior circulation strokes are half as likely to receive thrombolytic therapy and almost a third as likely to have thrombectomy, even after adjusting for baseline stroke severity scores. This is possibly due to difficulty in timely identification and diagnostic delays. There is need for better tools incorporating posterior circulation stroke signs and symptoms to allow for early detection and treatment.