Clinical Significance of Asymptomatic Intracranial Hemorrhage Following Thrombectomy for Large-Vessel Occlusion: Insight from the ANGEL-ACT Registry.

BACKGROUND AND PURPOSE: The prognostic significance of asymptomatic intracranial hemorrhage (aICH) after endovascular thrombectomy (EVT) for acute ischemic stroke remains uncertain. We investigated the association between aICH and clinical outcomes using data from a large prospective registry. METHODS: We analyzed patients with anterior circulation large-vessel occlusion from the ANGEL-ACT registry (November 2017 to March 2019) who underwent EVT. Patients were categorized into aICH, symptomatic ICH (sICH), and no ICH groups. The primary endpoint was 90-day modified Rankin Scale (mRS) score 0-2, and the safety outcome was death within 90 days. Multivariable logistic regression was performed to identify independent predictors of aICH. RESULTS: Among 1252 eligible patients, 221 (17.7%) developed aICH, 117 (9.3%) had sICH, and 914 had no ICH. Compared with patients without ICH, those with aICH had a lower rate of 90-day mRS 0-2 (13.6% vs 53.6%; OR 2.62, 95% CI 1.47 to 4.65; p = 0.001). No statistically significant difference was observed between the aICH and sICH groups despite a numerically lower rate of functional independence in the sICH group (13.6% vs 34.0%; OR 0.47, 95% CI 0.18 to 1.25; p = 0.131). Compared with patients with aICH, 90-day mortality was significantly higher in the sICH group (37.9% vs. 14.0%; OR 4.93, 95% CI 1.86 to 13.04; p = 0.001), but not significantly different in the no ICH group (9.0% vs. 14.0%; OR 0.77, 95% CI 0.37 to 1.64; p = 0.502). Valvular heart disease, more thrombectomy passes, higher admission blood glucose, and vascular perforation were independent predictors of aICH. CONCLUSIONS: aICH after EVT was associated with worse functional outcomes than no ICH, while mortality was lower than in sICH.