Abstract 187: Impact of General Anesthesia on Safety and Outcomes in the Endovascular Arm of IMS III

Objectives: Use of general anesthesia (GA) during endovascular therapy (ET) of AIS patients is controversial with some suggestion of worse outcomes and death. The IMS III trial permitted the study of the effect of GA in a prospectively collected data set to test two hypotheses: (1) intubation is associated with poorer outcomes and (2) there is no increase in the risk of SAH or sICH with local anesthesia (LA). Methods: IMS III was a randomized trial of IV tPA +/- ET in patients presenting within 3hrs of AIS onset. In addition to demographic and outcomes data (mRS, ICH, etc.), information was collected on GA use or not within 7hrs of stroke onset. A good outcome was defined as mRS≤2 at 90 days. A multivariable analysis adjusting for dichotomized NIHSS (8-19 vs. ≥20), age and time from onset to groin puncture was performed. Additional analyses of reasons for intubation are ongoing and will be part of the presentation. Results: Four-hundred-thirty-four patients were randomized to ET, 269(62%) with LA and 147(33.9%) with GA. They were evenly matched in demographics, medical comorbidities, time to tPA, time to groin puncture, 40minute post IV tPA bolus SBP and occlusion location/side. The baseline NIHSS were slightly lower in the LA group (median 16 vs. 18). The GA group was less likely to achieve a good outcome (RR 0.64, CI 0.49-0.84, p=0.001) and had a greater risk of in-hospital death (RR 3.11, CI 1.86-5.20, p<0.0001). There was an increased risk of SAH in the GA group (RR 1.79, CI 1.04-3.08, p=0.0364) but no statistically significant difference in sICH (RR 1.69, CI 0.79-3.61, p=0.18). The multivariable analysis confirmed the negative association between GA and good outcomes (RR 0.68, CI 0.52-0.90, p=0.0027). Conclusions: In the IMS III trial there was an association with worse neurological outcomes and increased mortality with ET under GA. Also, there was an association between GA and an increased risk of SAH. Although the reasons for these associations are not clear, these data support the use of LA when possible during ET.