Determinants for a low dose of alteplase and its relationship to a lower intracerebral bleeding risk in acute ischemic stroke.

Background: Factors for the utilization of intravenous thrombolysis with a low-dose of alteplase (0.6mg/kg) and whether the low-dose of alteplase could reduce the risk of intracerebral bleeding in acute ischemic stroke (AIS) remains uncertain. Aims: We aimed to investigate determinants for the utilization of intravenous thrombolysis with a low-dose of alteplase. We further assessed the association between the low-dose of alteplase and the intracerebral bleeding risk in AIS patients. Method: We included AIS patients who received intravenous thrombolysis using alteplase in this multicenter retrospective observational study. We investigated the association between baseline characteristics and the utilization of a low-dose of alteplase to identify determinants. We assessed the association of the low-dose of alteplase with the risk of symptomatic intracranial hemorrhage (sICH) using a multivariable logistic regression model. We further compared the rate of sICH and any ICH in patients in the low-dose group to those in the standard-dose group, using propensity score-matching data. Results: A total of 506 AIS patients were included in this study. The mean age was 67 (interquartile range [IQR] 59-75), and 178 (35.2%) were women. A total of 96 patients were treated with the low-dose. Age (adjusted odds ratio [OR] 1.02, 95% confidence interval [CI] 1.00 -1.04, p = 0.042), having a previous ischemic stroke (adjusted OR 2.01, 95%CI 1.11 - 3.64 p = 0.021) and increasing baseline systolic blood pressure (adjusted OR 1.12, 95%CI 1.00 - 1.26, p = 0.049) were determinants for the utilization of the low-dose. Multivariable logistic regression analysis showed that the low-dose was significantly associated with a reduced risk of sICH (adjusted OR 0.13, 95%CI 0.03 - 0.62, p = 0.01). Propensity score analysis showed that the rate of sICH was significantly lower in the low-dose group compared to standard-dose group (2 [2.3%] vs 10 [11.4%], p = 0.032). There was no significant difference in the rate of any ICH between two groups (14 [15.9%] vs 18 [20.5%], p = 0.434). Conclusions: Patients with increasing age, a higher baseline systolic blood pressure, and previous ischemic stroke were at a higher odd of receiving a low-dose of alteplase. The low-dose was associated with a lower risk of developing symptomatic intracranial hemorrhage.