Abstract
INTRO: Indications for MER are rapidly evolving. Real‐world patient selection for treatment is complex. Heterogeneity in vascular anatomy, comorbidities, and timing of presentation introduces significant variability in outcomes. Furthermore, evolving trial data and device technology continue to refine eligibility thresholds. These factors highlight the need for pragmatic, real‐world analyses to complement controlled trial results and better guide clinical decision‐making. METHODS: A retrospective study comparing outcomes from patients treated within and outside of the COR 1 LOE A guidelines with MER for LVO was performed. A total of 581 patients, 301 within and 280 outside of the guidelines were analyzed from a comprehensive stroke center. Multivariable logistic regression models for functional outcomes (mRS 0‐2) adjusted for age, sex, race, baseline NIHSS, hospital stay, stratified by occlusion site and by age were performed. Secondary outcomes including hospital mortality, NIHSS at discharge, mRS at discharge and procedural factors were analyzed. RESULTS: Treatment within guidelines was associated with better functional outcomes (mRS 0‐2) after adjusting for hospital stay length (44.8 % versus 32.9 %, OR 1.52, p=0.042). The benefit of guideline‐based treatment diminished with increasing age. Each additional year of age over 75 reduced the odds ratio for good outcome by approximately 3%. There was no significant difference in mortality between the groups. Hospital stay was independently associated with functional outcome, with each additional day decreasing the odds of good outcome by approximately 3% (OR 0.97 per day, p=0.001). The mean and median hospital stay length was similar between the two groups, suggesting that differences in hospital stay did not explain the treatment effect. Age and baseline NIHSS remained significant predictors of outcome. Treatment within guidelines showed significant benefit for M1 MCA occlusions (adjusted OR 2.21, p=0.018). No significant benefit was observed for ICA or multiple/tandem occlusions within the guidelines vs. outside of the guidelines. For ACA occlusions, limited data suggested a potential inverse relationship. There were no statistically significant differences in TICI > 2b scores nor procedural times. CONCLUSION: These findings suggest that while mechanical thrombectomy within guidelines generally provides better outcomes, the benefit varies significantly by occlusion site and age. The similar safety profile between within‐guideline and outside‐guideline treatment supports consideration of more individualized approaches to patient selection, particularly for older patients and those with specific vessel occlusion patterns.