Abstract: Objective To investigate the clinical efficacy and safety of intravenous thrombolysis in patients with acute severe cerebral infarction and analyze the risk factors of poor prognosis after thrombolysis. Methods This randomized controlled trial was conducted among 152 patients with acute severe cerebral infarction, with the onset time all within 4.5 h. The patients were randomized into control group (76 cases) and observation group (76 cases) and received treatment with routine therapy (antiplatelet aggregation, statins, neuroprotection and drugs that stimulate blood flow) and intravenous thrombolytic therapy with alteplase in addition to the routine therapy, respectively. The NIHSS scores were recorded at 24 h, 1 week and 1 month after the treatment. The mRS scores at 3 months and the incidence of symptomatic intracranial hemorrhage at one week after the treatment were compared between the two groups. According to mRS scores at 3 months, the patients in the observation group were divided into good prognosis group (30 patients) and poor prognosis group (46 patients), and the risk factors for poor prognosis were analyzed using univariate and multivariate Logistic regression analysis. Results At 24 h,1 week and 1 month after the treatment, the reduction of NIHSS scores was more significant in the observation group than in the control group (F=24.684, P<0.001). At 3 months after the treatment, the mRS scores were significantly lower (t=4.396, P<0.001) and the good prognosis rate was significantly higher (χ2=13.636, P<0.001) in the observation group than those of the control group. Symptomatic intracranial hemorrhage occurred in 4 cases in the observation group and in 2 cases in the control group within 1 week after the treatment (χ2=0.694, P=0.405). The time from onset to thrombolysis (OR=0.173, P=0.035), prethrombolytic systolic pressure (OR=0.869, P=0.019) and baseline NIHSS score (OR=0.466, P=0.011) were identified as independent risk factors for poor prognosis after intravenous thrombolysis. Conclusion Intravenous thrombolysis is effective and safe for patients with acute severe cerebral infarction, and the time from onset to thrombolysis, prethrombolytic systolic pressure and baseline NIHSS score are independent risk factors for a poor prognosis after intravenous thrombolysis.

Key words: severe cerebral infarction; intravenous thrombolysis; therapeutic effect; safety; risk factors