Abstract 046: Intracranial Stenting After Successful Recanalization in Patients with Intracranial Atherosclerosis Improves Outcomes ‐ RESCUE‐ICAS Secondary Analysis

Introduction Intracranial atherosclerosis (ICAS) is estimated to cause 10‐15% of large‐vessel occlusions (LVOs) in stroke. The prospective Registry of Emergent Large Vessel Occlusion Due to Intracranial Stenosis (RESCUE‐ICAS) demonstrated better outcomes in patients undergoing adjuvant acute stenting of the underlying ICAS plaque than in those who underwent endovascular thrombectomy (EVT) alone. We present a secondary analysis of RESCUE‐ICAS in which we evaluated the safety and radiographic and clinical outcomes of acute stenting in patients with ICAS‐LVO who had successful recanalization ( modified treatment in cerebral infarction ( mTICI) score≥2B). Methods RESCUE‐ICAS was an international, multicenter, observational, prospective cohort study of 417 consecutive adult patients who underwent EVT secondary to ICAS‐LVO, as defined by 50‐99% stenosis or reocclusion after EVT. Patients who experienced successful recanalization (mTICI≥2B) at the end of thrombectomy and prior to stenting (in the stenting group) were included in this secondary analysis. Our primary endpoints were modified Rankin Scale (mRS) score at 90 days and 24‐hour infarct volume on MRI. Safety endpoints included symptomatic intracranial hemorrhage and death at 90 days. Subanalysis of all patients who experienced mTICI≥2B after initial EVT alone prior to stenting was used to determine the impact of acute stenting on this cohort. Results A total of 351 (84.2%) patients in the total cohort had mTICI≥2B at the end of the procedure. Stenting was performed in 181 (51.6%) of these patients. The odds of functional independence at 90 days with mRS 0‐2 was higher for those who acutely underwent stenting (adjusted odds ratio 1.88 [95% CI 1.09‐3.26]; p=0.024). Patients who underwent stenting were more likely to have 24‐hour MRI infarct volume <30 mL than those who underwent EVT alone (n=131, 70.1% vs 54.8%, p=0.022; adjusted odds ratio (aOR) 3.21 [95% confidence interval (CI) 1.46‐7.07]; p=0.004). In our subanalysis, patients with mTICI≥2B who underwent acute intracranial stenting experienced a higher odds of mRS 0‐2 at 90 days (aOR 2.19 [95% CI 1.01‐4.74]; p=0.046) and 24‐hour MRI infarct volume <30 mL (aOR 3.27 [95% CI 1.047‐10.19]; p=0.042). There was no significant difference between the stenting and EVT alone groups in symptomatic intracranial hemorrhage (n=22, 7.2% vs 5.3%, p=0.466) or death at 90 days (n=85, 22.7% vs 25.9%, p=0.480). Conclusions Patients with ICAS‐LVO who had successful recanalization (mTICI≥2B) at the end of the procedure and underwent stenting had lower mean infarct volumes on 24‐hour MRI and better mean mRS at 90 days than those who had successful recanalization without stent placement. Further analysis also demonstrated that those who had mTICI≥2B after EVT alone who then underwent acute stent placement still had lower infarct volumes on 24‐hour MRI and improved mRS at 90 days when than those who did not undergo stenting after successful recanalization. Our analysis suggests that acute stent placement in patients experiencing successful recanalization leads to better clinical and radiographic outcomes, without increased risk of morbidity and mortality.