Effects of Computed Tomography Hyperdense Middle Cerebral Artery Sign on the Efficacy of Endovascular Therapy in Acute Ischemic Stroke With Large Infarcts: A Subgroup Analysis of the ANGEL‐ASPECT Trial

Background The hyperdense middle cerebral artery sign (HMCAS) observed on noncontrast computed tomography is associated with thrombus composition and thrombectomy outcomes. The impact of HMCAS on the efficacy of endovascular therapy (EVT) in patients with large core infarcts remains unclear. Methods This analysis uses data from the ANGEL‐ASPECT (Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients With a Large Infarct Core) trial, a multicenter randomized controlled trial conducted in China. Patients with acute ischemic stroke and anterior‐circulation large‐vessel occlusion were categorized according to whether HMCAS was present on baseline noncontrast computed tomography. The primary outcome was the 90‐day modified Rankin Scale score. Results Of the 432 patients included in this analysis, 33% were HMCAS positive on baseline noncontrast computed tomography. In the EVT‐treated patients, patients with HMCAS had worse functional outcomes than those without HMCAS (adjusted relative risk, 0.44 [95% CI, 0.26–0.73]; P =0.002). Patients with HMCAS required a greater number of thrombectomy passes ( P <0.001). Among patients without HMCAS, EVT was associated with better functional outcomes than medical management (generalized odds ratio [OR], 2.78 [95% CI, 1.80–4.27]; P <0.001), whereas this benefit was not statistically significant among patients with HMCAS (adjusted OR, 1.69 [95% CI, 0.93–3.08]; P =0.09). There was no significant interaction between HMCAS status and treatment assignment ( P =0.19). Conclusions In this subgroup analysis comparing EVT with medical management, we found no statistically significant treatment–by–HMCAS status interaction, indicating that the benefits of EVT extend to patients with large core infarcts irrespective of HMCAS status. However, the magnitude of benefit appears greater in patients without HMCAS, whereas those with HMCAS tend to have a poorer overall prognosis. Registration URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT04551664.