Asymptomatic Hemorrhagic Events and Functional Outcomes in Acute Stroke

Importance Asymptomatic hemorrhagic infarction (HI) and subarachnoid hemorrhage (SAH) after endovascular treatment (EVT) for acute ischemic stroke are commonly considered low risk, but their long-term impact on functional outcomes is unclear. Objective To determine whether asymptomatic HI and SAH are associated with worse 90-day functional recovery in patients with acute ischemic stroke treated with EVT. Design, Setting, and Participants This is a secondary analysis of the DIRECT-MT randomized clinical trial, which compared intravenous thrombolysis prior to EVT with EVT alone. The multicenter study was conducted at tertiary hospitals in China between 2016 and 2019 with 90-day follow-up. Trial patients with asymptomatic HI, SAH, or no hemorrhage were included in the present analysis, which was performed in December 2024. Exposure Asymptomatic HI and SAH detected on follow-up imaging. Main Outcomes and Measures The primary outcome was the score on the modified Rankin scale (mRS) assessed at 90 days. Secondary analyses categorized mRS scores into thresholds of 0 to 1, 0 to 2, and 0 to 3, representing excellent, good, and favorable recovery, respectively. Results A total of 490 patients were included (median [IQR] age, 70 [60-76] years; 210 [42.9%] female), with 133 (27.1%) in the asymptomatic HI and SAH group and 357 (72.9%) in the no hemorrhage group. After propensity score matching, the odds ratio of having a worse mRS scores at 90 days in the asymptomatic HI and SAH group compared with the no hemorrhage group was 2.59 (95% CI, 1.45-4.63; P = .001). For binary outcomes, asymptomatic HI and SAH were consistently associated with worse recovery across mRS score thresholds of 0 to 1 and 0 to 2 in all models. Conclusions and Relevance In this secondary analysis of a randomized clinical trial, asymptomatic HI and SAH were associated with worse 90-day functional outcomes in patients with acute ischemic stroke treated with EVT. These findings emphasize the need for close monitoring and tailored management strategies in patients with asymptomatic hemorrhagic events following thrombectomy. Trial Registration ClinicalTrials.gov Identifier: NCT03469206