Introduction Prior data have described predictors of early neurologic improvement (ENI) post endovascular thrombectomy (EVT) in terms of demographics, presenting neurologic deficits, baseline function and radiographic characteristics. Herein, we aimed to describe intraprocedural predictors of ENI in patients presenting with large vessel occlusions (LVO).

Methods We performed a retrospective review of our prospectively maintained thrombectomy database to identify adult patients over 18 years of age, presenting with a large vessel occlusion requiring mechanical thrombectomy, between 1/2021-12/2022. We collected baseline demographics and comorbidities, in addition to presenting NIH Stroke Scale (NIHSS) score, ASPECTS score, and baseline Modified Rankin scale (mRS). We collected additional procedural data including mode of anesthesia, last known well (LKW) to groin puncture time, groin puncture to recanalization time, mechanism of first pass, mechanism of final pass, total number of passes, and final recanalization (TICI) score. Our primary outcome was ENI, defined as NIHSS improvement to <6 within 24 hours of procedure.

Results We identified 413 patients who presented with an LVO and underwent EVT in 2021 and 2022. Median age was 72 (Interquartile range (IQR) 61-81), 210 were females (51.3%). Median presenting NIHSS score was 16 (IQR 10-21), and median NIHSS score within 24 hours was 11 (IQR 4-19). Total of 133 (32.2%) patients had ENI (NIHSS of less than 6) within 24 hours. Univariate analysis revealed that ENI patients were younger (66 vs 75, p=0.00), more likely to have a baseline mRS of 0 (83.1% vs 50.6%, p=0.00), more likely to have excellent recanalization (TICI 2C or above) (84.7% vs 61%, p=0.00), lower number of passes (p=0.04), and shorter groin to recanalization time (34 vs 48 minutes, p=0.01). ENI patients were also more likely to receive moderate anesthesia care rather than general or local anesthesia (75% vs 53.4%, p=0.00). The remaining demographics and medical comorbidities were similar between both groups. Baseline ASPECTS score, last known well to groin puncture time, tandem occlusion, and occlusion location were also similar between both groups. In a multivariate regression analysis adjusting for factors mentioned above, lower presenting NIHSS, younger age, lower number of passes, administering monitored anesthesia care, and excellent recanalization (Odds Ratio 0.90, 95% Confidence Interval (0.86-0.94), p=0.004) significantly predicted an NIHSS of less than 6 within 24 hours. First pass effect, procedural duration, final pass mechanism, and first pass mechanism did not significantly predict ENI in this model. A sub analysis of delta NIHSS in 24 hours, revealed that younger patients, lower number of passes, shorter procedural time, and excellent recanalization predicted a decrease of 6 points or above in NIHSS. Excellent recanalization remained a significant predictor of delta NIHSS in a multivariate model adjusting for similar covariates.

Conclusion In a large retrospective database, we found that excellent recanalization, defined as TICI 2C or above, significantly predicted ENI and delta NIHSS of 6 or above within 24 hours of procedure in patients with acute ischemic stroke from a large vessel occlusion.

Disclosures M. Al-Kawaz: None. D. Goldman: None. J. Scaggiante: None. K. Yaeger: None. T. Hardigan: None. C. Kellner: None. J. Fifi: None. J. Mocco: None. S. Majidi: None.