O05 Treatment effect of successful recanalization after mechanical thrombectomy: unraveling the influence of NIHSS and ASPECTS on reperfusion-related neurological improvement

<h3>Introduction</h3> Boundaries of mechanical thrombectomy are continuously expanding, the TENSION trial[1] showed efficiency and safety in low ASPECTS patients, ongoing trials (ENDOLOW, MOSTE) investigate patients with low NIHSS[2]. <h3>Aim of Study</h3> To analyze treatment effects for stroke collectives stratified by NIHSS at admission and ASPECTS based on large-scale registry data, reflecting association of clinical-core mismatch and outcomes in clinical practice. <h3>Methods</h3> All patients enrolled in the German Stroke Registry (GSR) between 06/2015-12/2021 were screened. Patients were stratified into 9 subgroups by ASPECTS (I:10, II:9-8, III:7-0) and NIHSS at admission (A:0-10, B:11-15, C:16-42). Treatment effects were defined as decrease of the 90d mRS and estimated using double-robust Inverse-Probability-Weighted-Regression-Adjustment (IPWRA). <h3>Results</h3> 4168 patients were analyzed (table 1). Overall, mTICI=2b and mTICI=3 vs. mTICI=0-2a were associated with a 1.11 [95%CI:0.93;1.29] and 1.44 [1.27;1.61] decrease of 90d-mRS. Lowest treatment effects were observed in patients with high ASPECTS and low NIHSS (1.06 [0.58;1.53]) and with low ASPECTS and high NIHSS (1.05 [0.73;1.38]. Highest treatment effect with 2.34 [1.70;2.99] was estimated for patients with ASPECTS=10 and NIHSS=11-15. Highest benefit of mTICI=3 vs. 2b was observed for NIHSS&gt;15 and ASPECTS=10 (0.71 [0.34;1.08])(figure 1) <h3>Conclusion</h3> Highest reduction of 90d-mRS after successful recanalization was observed in patients with ASPECTS=10 and NIHSS=11-15, corresponding to high clinical-core-mismatch. Lowest treatment effects were estimated for subgroups with NIHSS&gt;15 and ASPECTS&lt;8 as well as for NIHSS=0-10 and ASPECTS=10 (low clinical-core-mismatch). mTICI=3 vs. mTICI=2b showed highest benefit in patients with NIHSS&gt;15 and ASPECTS=10, no significant benefit was observed for low clinical-core-mismatch. <h3>Disclosure of Interest</h3> yes Helge Kniep and Fabian Flottmann are consultants for Eppdata GmbH. Helge Kniep is shareholder of Eppdata GmbH. Götz Thomalla received fees as consultant from Acandis, Boehringer Ingelheim, Bayer, and Portola, and fees as lecturer from Acandis, Alexion, Amarin, Bayer, Boehringer-Ingelheim, BMS/Pfizer, Daiichii Sankyo and Portola. He serves in the board of the TEA Stroke Study and of ESO. Jens Fiehler is consultant for Cerenovus, Medtronic, Microvention, Penumbra, Phenox, Roche and Tonbridge. He serves in the advisory board of Stryker and Phenox. He is stock holder of Tegus Medical, Eppdata and Vastrax. He serves as Associate Editor at JNIS.