Identifying Predictors for Endovascular Therapy Outcomes in Patients with Medium Vessel Occlusions

Introduction/Purpose Randomized trials suggest endovascular therapy (EVT) may not benefit patients with medium vessel occlusions (MeVOs), though heterogeneity—inclusion of very mild cases—limits interpretation. We aimed to model 90‐days functional outcomes in MeVO patients to better identify high‐risk patients. Materials/Methods This is a sub‐study of an international prospectively maintained dual‐center database of consecutive patients with primary MeVOs (distal or non‐dominant M2, M3, A2‐A3, P1‐P2) who underwent EVT or medical management (MM) between January 2022 and July 2024. The primary outcome was poor functional outcome (defined as modified Rankin Scale [mRS] between 3‐6) at 90‐days. We develop two independent multivariable logistic regression models to assess association of admission characteristics with poor outcome and also assess predictive performance of admission characteristics. Each independent model adjusted for age, ASPECTS score, used of IV thrombolytics, baseline mRS, NIHSS at admission, and EVT. Predictive performance was assessed via repeated 10‐fold cross‐validation (500 repetitions) and bootstrap resampling (500 iterations), with metrics included area under the curve (AUC), sensitivity, and specificity. Results We included 288 patients (median age 78 IQR [68‐84], 54.4% were male). Among them 80.2% (N=231) underwent EVT and 19.8% (N=57) received MM. The most common occlusion sites were in the M2 and M3 segments (71.5%; N=206). Our final model selection included age, ASPECTS score, used of IV thrombolytics, baseline mRS, NIHSS at admission, and EVT and did not find an association between EVT and poor functional outcome at 90‐days (aOR = 0.67 [95% CI: 0.29, 1.54]) ( Table 1 ). Our predictive modeling had moderate discrimination (sensitivity 64.9% [95% CI: 50.2%‐78.6%]; specificity 74.1% [60.1%‐87.5%]; AUC 0.752 [0.670‐0.818]) ( Figure 1 ). Conclusion Our findings suggest that age, ASPECTS score, baseline mRS, and NIHSS at admission may identify help high‐risk patients for future studies on EVT effects. However, further studies are needed to better delineate optimal cut‐offs.