Prognosis and risk factors of asymptomatic intracranial hemorrhage after endovascular treatment of large vessel occlusion stroke: a prospective multicenter cohort study.

BACKGROUND Asymptomatic intracranial hemorrhage (aICH) is a common occurrence after endovascular therapy (EVT) for acute ischemic stroke (AIS). The aims of this study are to address its impact on 3-month functional outcome and to identify risk factors for aICH after EVT. METHODS Patients with AIS due to anterior circulation large vessel occlusion treated by EVT were enrolled in a multicenter prospective registry. Based on imaging performed 22h-36h post-EVT, we included patients with no ICH or aICH. Poor outcome defined as a 3-month mRS 4-6 and overall 3-month mRS distribution were compared according to presence/absence of aICH, and aICH subtype using logistic regression. We assessed the risk factors of aICH using a multivariate logistic-regression model. RESULTS Among 1,526 patients included, 653 (42.7%) had aICH. Patient with aICH had a higher rate of poor outcome OR 1.88 [95%CI, 1.44 to 2.44]. Shift analysis of mRS found a fully-adjusted OR of 1.79 [95%CI, 1.47 to 2.18]. Hemorrhagic infarction (OR 1.63 [95%CI, 1.22 to 2.18]) and parenchymal hematoma (OR 2.99 [95%CI, 1.77 to 5.02]) were associated with higher risk of poor outcome. Male sex, diabetes, coronary artery disease, baseline NIHSS and ASPECTS, number of passes and onset to groin puncture time were independently associated with aICH. CONCLUSIONS Patients with aICH, irrespectively of the radiological pattern, have a worse functional outcome at 3-months compared with those without ICH after EVT for AIS. The number of EVT passes and the time from onset to groin puncture are factors that could be modified to reduce these deleterious ICH.