Nimodipine in catheter flush solutions is associated with reduced vasospasm risk in endovascular stroke treatment

BACKGROUND: Vasospasm during endovascular treatment (ET) for ischemic stroke is increasingly recognized as a relevant complication associated with worse functional outcomes. The preventive effect of using nimodipine continuously administered intra-arterially in catheter flush solutions (FS) and its impact on functional outcomes are uncertain. METHODS: We analyzed data from the German Stroke Registry-Endovascular Treatment, a prospective, multicenter registry including patients treated with ET at 25 centers between June 2015 and December 2023. Center-specific FS protocols were assessed and patients were stratified by use of nimodipine in FS. The primary outcome was vasospasm occurrence. Secondary outcomes included the 90-day modified Rankin Scale (mRS) score. Analyses used inverse probability of treatment weighting (IPTW)-adjusted logistic regression models. RESULTS: Among 16 583 patients (mean age 73.6 years; 51.7% female), nimodipine-containing FS were used in 7548 patients (45.5%) and FS without nimodipine in 9035 patients (54.5%). Nimodipine-containing FS were associated with lower odds of vasospasm (IPTW-adjusted risk 1.8% vs 4.8%; IPTW-adjusted OR 0.38; 95% CI 0.30 to 0.47; P<0.001). This association was not modified by age (≤60 vs >60 years), stroke type (anterior vs posterior circulation), occlusion type (large vs medium vessel occlusion), or thrombectomy technique (contact aspiration vs stent retriever vs combined/cross-over). Nimodipine-containing FS were associated with higher odds of achieving 90-day mRS 0-1 (IPTW-adjusted OR 1.23; 95% CI 1.13 to 1.34; P<0.001) and mRS 0-2 (IPTW-adjusted OR 1.16; 95% CI 1.08 to 1.25; P<0.001). CONCLUSIONS: Use of nimodipine in catheter FS is associated with a lower risk of vasospasm and improved functional outcomes. Randomized clinical trials are warranted to confirm these findings. TRIAL REGISTRATION NUMBER: NCT03356392.