Vasospasm During Endovascular Treatment of Ischemic Stroke: Associated Factors, Impact on Outcomes, and the Effect of Intraarterial Nimodipine

BACKGROUND: Vasospasm occurs in up to 20% of patients with acute ischemic stroke undergoing endovascular treatment, 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 use. METHODS: We used data from the German Stroke Registry-Endovascular Treatment, an investigator-initiated, prospective, observational, multicenter registry of patients with acute stroke who underwent endovascular treatment at 25 centers between June 2015 and December 2023. Patients with and without vasospasm were analyzed, and among those with vasospasm, we compared outcomes based on intraarterial nimodipine use. The primary outcome was the distribution of modified Rankin Scale scores at 90 days. Secondary outcomes included 90-day mortality, early neurological deterioration, symptomatic intracranial hemorrhage at 24 hours, and successful recanalization (modified Thrombolysis in Cerebral Infarction Score of 2b to 3). Analyses used Inverse Probability of Treatment Weighting adjusted logistic regression; variable selection was performed using Least Absolute Shrinkage and Selection Operator regression. RESULTS: Seventeen thousand nine hundred eighty-five patients (mean age 73.6 years; 51.2% female) were included in the analysis. Of these, 578 (3.2%) had vasospasm reported, and 300 (58.4%) of those received intraarterial nimodipine. Vasospasm was associated with a shift towards worse modified Rankin Scale outcome (adjusted odds ratio, 1.25 [95% CI, 1.02-1.53]) and higher mortality (36% versus 29.7%; adjusted odds ratio, 1.35 [95% CI, 1.05-1.75]). Intraarterial nimodipine was associated with reduced rates of early neurological deterioration (adjusted odds ratio, 0.54 [95% CI, 0.31-0.91]). Variables associated with vasospasm included younger age, active smoking, M2 occlusion, first-line stent retriever thrombectomy, and multiple recanalization attempts. CONCLUSIONS: Vasospasm during endovascular treatment is associated with worse outcomes and increased mortality, and should be regarded as a serious procedural complication. Younger patients who are active smokers, presenting with distal occlusions, and require multiple recanalization attempts are at higher risk. Intraarterial nimodipine appears to be a sensible treatment as it may mitigate neurological deterioration without signals of potential harm.