Bridging Thrombolysis Does Not Achieve Better Outcomes Compared to Direct Mechanical Thrombectomy in Stroke Due to Internal Carotid Artery Occlusion

Background and purpose. Mechanical thrombectomy (MT) is an effective treatment for patients with acute ischaemic stroke secondary to internal carotid artery (ICA) occlusion. Intravenous thrombolysis (IVT) prior to MT is also commonly administered in suitable patients. This study aimed to compare the outcomes of patients with acute ICA stroke who were treated with direct MT versus combined IVT plus MT. Additionally, analysis was performed in different subgroups of patients such as those with large artery stenosis (LAA) to evaluate which subgroup of patients would benefit most from bridging IVT.Methods. This multicenter retrospective cohort study included patients who were treated for acute ICA stroke from three comprehensive stroke centers between January 2015 and December 2019. Patients received direct MT or combined bridging IVT plus MT. Primary outcome was favorable functional outcome defined as modified Rankin Scale (mRS) 0–2 measured at 90 days after discharge. Secondary outcome measures included mRS on discharge, inpatient mortality and complications such as symptomatic intracranial hemorrhage (sICH), subarachnoid haemorrhage (SAH) and embolism of thrombus to new territories.Results. Among 352 patients, 178 (50.6%) patients underwent bridging IVT followed by MT and 174 (49.4%) underwent direct MT. The mean ± standard deviation age was 69.8 ± 14.6 years, 50.9% were male and median National Institutes of Health Stroke Scale was 16 (interquartile range). At 90-days after discharge, patients who underwent bridging IVT had similar functional outcomes as those who underwent direct MT (33.5% vs 27.7%, P = 0.255). On multivariable analyses, bridging IVT was not associated with improvement in discharge mRS score, 90-day mRS score, decreased mortality or difference in rate of complications compared to direct MT. In subgroup analyses, patients with underlying atherosclerosis treated with bridging IVT compared to direct MT had a higher rate of favorable functional outcome at 90 days (33.9% vs. 14.0%, P = 0.022)Conclusions. Bridging IVT is not associated with better functional outcomes compared to direct MT in ICA stroke. However, in the subgroup of patients with underlying large-artery atherosclerosis stroke mechanism, bridging IVT appears to potentially confer beneficial outcomes. This should be validated in larger studies.