Association of CT perfusion parameters with outcomes in patients with medium vessel occlusion undergoing endovascular thrombectomy

Background: Imaging biomarkers obtained on computed tomography perfusion (CTP) have proven effective in predicting outcomes after endovascular thrombectomy (EVT) in patients with large vessel occlusion stroke. However, the association of CTP imaging biomarkers with outcomes in medium-size vessel occlusion (MeVO) stroke patients remains unknown. Objectives: Therefore, we aimed to explore whether CTP parameters can be used for selection of a subset of MeVO patients that are more likely to benefit from EVT. Methods: Consecutively enrolled acute MeVO stroke patients treated with EVT were included. All patients underwent CTP on admission and follow-up noncontrast CT 24 h post-EVT. CTP parameters including core and penumbra volumes were obtained. Excellent outcome, defined as a modified Rankin score of 0–1 at 90 days poststroke was the primary outcome, and survival at 90 days was the safety outcome. Regression analyses were performed to examine the associations between different CTP parameters and outcomes. Results: Overall, 70 patients with MeVO were included (47% male, median age 75), and 66 (94%) had long-term follow-up data. Of those included, 26 patients (39%) had excellent outcomes and 2 (3%) had symptomatic intracerebral hemorrhage. On regression analysis, hypoperfused volumes on CTP were associated with excellent outcomes (adjusted odds ratio (aOR) 1.02, 95% confidence intervals (CI) 1.001–1.037), whereas core volume was not. Other factors associated with excellent outcome included admission National Institutes of Health Stroke Scale score (aOR 0.85, 95% CI 0.73–0.98) and lack of hypertension (aOR 0.07, 95% CI 0.07–0.62). Core or penumbral volumes were not associated with survival. Conclusion: Higher volumes of hypoperfused tissue on CTP are associated with a higher likelihood of excellent outcome. Core and penumbral volumes are not associated with increased mortality in patients with MeVO that undergo EVT.