Abstract 55: the Probability of Ischemic Stroke Endovascular Targets: Extended Treatment Window for Women

Introduction: The decline in the probability of a therapeutic target over time from stroke onset may underlie the declining efficacy of stroke therapies over time. The persistence of a therapeutic target in some patients supports the use of imaging to identify candidates for treatments at later time windows. In light of the known sex differences in stroke subtype, severity and outcomes, we investigated sex differences in the probability of endovascular targets and its relationship of time from stroke onset. Hypothesis: The rate of endovascular targets is different in women than men and sex interacts with endovascular target timing. Methods: A prospective consecutive cohort of 1,092 ischemic stroke patients, with NIHSS > 3, in whom MRI performed within 24 hours of last known well (LKW), was evaluated for potential endovascular therapeutic (EVT) target: intracranial ICA or MCA-M1 occlusion on MRA. Time from LKW, sex, age and the presence of perfusion-diffusion mismatch were modeled as predictors of EVT target. Results: Overall, women had a significantly higher probability of presenting with endovascular targets with an adjusted odds ratio, OR, of 1.450, p=0.013. The probability of target detection decreased over time for both sexes, but the rates of decline differed significantly (p=0.034) in multivariate models, with targets consistently present at later times in women. A multivariate model of endovascular target adjusted for the presence of mismatch and the interaction between sex and mismatch resulted in a sex difference of 230% (odds ratio of 2.32, p=0.010), independent of time from onset. Conclusions: Women demonstrated prolonged presence of endovascular targets. In light of recent endovascular trial results, this identification of disparities in imaging biomarkers represents a step toward further refining the imaging selection of patients for acute reperfusion therapy and trials. The results implicate the need to stratify considerations of treatment intervention based on sex due to the potentially extended therapeutic time window for women.