ABSTRACT NUMBER: ESOC2026A1345 VASOSPASM DURING ENDOVASCULAR TREATMENT OF ISCHEMIC STROKE: ASSOCIATED FACTORS, IMPACT ON OUTCOMES, AND THE EFFECT OF INTRAARTERIAL NIMODIPINE

Abstract Background and aims Vasospasm occurs in up to 20% of patients with acute stroke undergoing ET, but its clinical impact remains controversial. Intraarterial nimodipine is administered occasionally to treat vasospasm, though its efficacy is uncertain. We aimed to identify factors associated with vasospasm, delineate the impact on clinical outcomes, and assess the effects of intraarterial nimodipine. Methods We used data from the German Stroke Registry-Endovascular Treatment, analyzing stroke patients who underwent ET at 25 centers between 06/2015 and 12/2023. Patients with and without vasospasm were analyzed, and among those with vasospasm, we compared outcomes based on intraarterial nimodipine use. Primary outcome was the mRS at 90 days. Secondary outcomes included 90-day mortality, early neurological deterioration (END) and sICH. Results 17,985 patients (mean age 73.6 years; 51.2% female) were included in the analysis. Of these, 578 (3.2%) had vasospasm, and 300 (58.4%) of those received intraarterial nimodipine. Vasospasm was associated with a shift toward worse mRS outcomes (aOR, 1.25 [95%CI, 1.02-1.53]) and higher mortality (36% versus 29.7%; aOR, 1.35 [95%CI, 1.05-1.75]). Intraarterial nimodipine was associated with less END (aOR, 0.54 [95%CI, 0.31-0.91]). Variables associated with vasospasm included younger age, active smoking, M2 occlusion, and multiple recanalization attempts. Conclusions Vasospasm during ET is associated with worse outcomes and increased mortality, and should be regarded as a serious procedural complication. Younger patients who are active smokers, with distal occlusions, requiring multiple recanalization attempts are at higher risk. Intraarterial nimodipine appears to be a sensible treatment as it may mitigate END without signals of potential harm. Conflict of interest JW, AR, CR, SW, TBB and HZ report no conflict of interest. MTB reports compensation from Stryker, Balt USA, LLC, and MicroVention, Inc. for consultant services. CHN received funding for travel or speaker honoraria from Alexion, AstraZeneca, Bayer, BMS and Pfizer outside of this work and reports compensation from Novartis for consultant services. LK received funding for travel or speaker honoraria from Alexion, AstraZeneca, Bayer Vital, Boehringer Ingelheim, Bristol-Meyer-Squibb, Daiichi Sankyo, Lilly and Pfizer outside of this study.