Sex-Based Differences in Endovascular Thrombectomy Outcomes for Large Ischemic Stroke: A SELECT2 Subanalysis

BACKGROUND: Several social and biological factors are shown to differentially affect stroke outcomes between men and women. We evaluated whether clinical outcomes and endovascular thrombectomy (EVT) treatment effects differed between the sexes in patients presenting with large ischemic stroke. METHODS: The SELECT2 trial (A Randomized Controlled Trial to Optimize Patient's Selection for Endovascular Treatment in Acute Ischemic Stroke) was a randomized controlled trial assessing the efficacy and safety of EVT in patients with large strokes across the United States, Canada, Europe, Australia, and New Zealand between October 2019 and September 2022. In this subanalysis, baseline characteristics and clinical and imaging outcomes were compared between women and men, each further divided into cohorts receiving medical treatment without and with EVT. Functional outcomes at 90-day and 1-year follow-ups were assessed using regression models, adjusting for potential confounders. Sex-related effect modification was examined. RESULTS: Women accounted for 145 (41%) of 352 patients enrolled in the SELECT2 trial. Seventy-one (49%) of 145 women and 109 (53%) of 207 men underwent EVT. Endovascular intervention was associated with better functional outcomes (women: adjusted generalized odds ratio, 1.73 [1.22-2.45]; men: adjusted generalized odds ratio, 1.66 [1.24-2.23]; P-int: 0.94), functional independence (women: EVT, 20% versus medical management, 4%; adjusted risk ratio [aRR], 5.04 [1.59-16.02]; men: EVT, 20% versus medical management, 9%; aRR, 1.99 [0.99-4.02]; P-int: 0.20), and independent ambulation (women: EVT, 39% versus medical management, 16%; aRR, 2.44 [1.40-4.24]; men: EVT, 38% versus medical management, 20%; aRR, 1.98 [1.29-3.03]; P-int: 0.67) in both men and women at 90-day follow-up, without significant heterogeneity. Similar results were observed at 1-year follow-up. In women, as age increased (aRR, 0.97 [95% CI, 0.95-0.99]; P=0.004 per year) and core volume estimates increased (aRR, 0.99 [95% CI, 0.98-1.00]; P=0.015 per mL increase), the rate of independent ambulation after EVT decreased. A similar association of age and core volume was seen in men. CONCLUSIONS: EVT treatment benefit was maintained in both women and men, with higher rates of functional independence and independent ambulation as compared with medical management. Age and estimated core infarct volume were independently associated with independent ambulation in both male and female patients. EVT should be equally considered for patients of both sexes meeting large core eligibility criteria.