Abstract TMP12: The Effect of Anesthesia Type on Endovascular Thrombectomy Outcomes is Modified by Stroke Size: A Secondary Analysis From the SELECT Study

Background: The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Methods: In the prospective multicenter cohort study of imaging selection for EVT (SELECT), patients were stratified based on their anesthesia type into general anesthesia (GA) and conscious sedation (CS). EVT times and outcomes were compared. Further we assessed the impact of ischemic core size (rCBF Results: Of 361 enrolled, 285 received EVT. 129 (45%%) received GA and 156 (54%) CS. The baseline characteristics were similar, except for presentation NIHSS (GA 17(13-21), CS 15(11-20), p=0.027) and ischemic core volume (GA 14.1 cc (0-38) vs CS 6.3(0-26.1), p=0.034). GA was associated with numerically longer arrival to GP times 92 (68—115) vs. 85(60-117) mins, p=0.58. After adjustment for baseline imbalances, patients who received CS had a shift toward better outcome (adj cOR 1.72, 95% CI=1.08-2.75, p=0.022) with higher functional independence rates 56.8% vs 48.8%, p=0.75. Furthermore, GA was associated with higher mortality rates (19% vs 9%, p=0.017), figure 1A. In patients with core volume ≥ 50 cc, there was a trend for a shift towards better outcomes (adj cOR=5.84, 95%CI= 0.90-38.00, P=0.065), figure 1B while there was no difference in patients with core volume < 50 cc (adj cOR=1.01 (95%CI 0.53-1.94, P=0.96), figure 1C. There was an interaction between core volume size and anesthesia type on functional outcome (p=0.042). For every 10cc increase in the core volume, the odds of attaining better functional outcome decreased by 29% (adjusted cOR: 0.71, 95% CI=0.61-0.83, p Conclusion: Conscious sedation was associated with a shift towards better EVT outcomes. This effect was driven by patients with larger ischemic core volumes and has implications for randomized trials of conscious sedation vs general anesthesia.