关键词: 卒中; 醒后卒中; 超时间窗; 静脉溶栓; 磁共振成像

Abstract: Objective  To explore the safety and efficacy of MRI-guided thrombolysis beyond time window in patients with acute ischemic stroke in a county-level hospital in China.
Methods  The consecutive patients with first acute ischemic stroke who underwent intravenous thrombolysis guided by MRI (mismatch of high signal on DWI-equal signal on FLAIR) in Xingguo People’s Hospital, Jiangxi Province from July 2021 to January 2022 were enrolled in this prospective study. The patients who underwent intravenous thrombolysis beyond time window (>4.5 hours) were selected as the observation group, and the patients who underwent intravenous thrombolysis within 4.5 hours of onset were selected as the control group. The primary efficacy outcome was a good functional outcome (defined as a mRS score of 0 to 1) at 3 months. The primary safety outcome was symptomatic hemorrhagic transformation within 36 hours (defined as an increase of 4 score in NIHSS from baseline and MRI-based intracranial hemorrhage). The efficacy and safety of thrombolysis were compared between the two groups. The NIHSS scores at different time points (baseline, at 24 hours after thrombolysis and at discharge) were compared in each group.
Results  A total of 39 cases were included in the observation group, with a mean age of 69.6±10.4 years and 23 males; and 60 cases in the control group, with a mean age of 66.1±11.0 years and 39 males. There was no statistical difference in the percentage of 90-day good functional outcome between the two groups (observation vs. control: 64.1% vs. 76.7%, P=0.175); and there was also no statistical difference in the percentage of symptomatic hemorrhagic transformation between the two groups (observation vs. control: 0 vs. 1.7%, P=0.418). The NIHSS scores at 24 hours [3.0 (2.0-5.0)] and at discharge [1.0 (0-5.0)] improved compared to the baseline NIHSS [4.0 (3.0-8.5)] in the observation group, and the NIHSS score at discharge [0 (0-2.0)] improved compared to the baseline NIHSS [4.0 (2.0-8.3)] in the control group, with all the above differences having statistical significance.
Conclusions  The MRI-guided intravenous thrombolysis beyond time window in patients with ischemic stroke is feasible and safe in county-level hospitals in China.

Key words: Stroke; Wake-up stroke; Beyond time window; Intravenous thrombolysis; Magnetic resonance imaging