Efficacy and Safety of Low-Dose Versus Standard-Dose Alteplase to Treat High-Risk Pulmonary Embolism

Background The optimal dosing of alteplase in patients with high-risk pulmonary embolism is widely debated. Objective To evaluate outcomes in patients with high-risk pulmonary embolism who received alteplase at a low dose or a standard dose. Methods This was a retrospective cohort analysis of 65 patients who received alteplase for high-risk pulmonary embolism at a large academic medical center between June 1, 2011, and August 31, 2022. Patients were placed in 2 cohorts according to initial dose: low-dose alteplase (50 mg) and standard-dose alteplase (100 mg). The primary outcome was sustained hemodynamic stability within 24 hours of the start of alteplase infusion. Secondary outcomes included in-hospital mortality, duration of mechanical ventilation, hospital and intensive care unit length of stay, and major bleeding. Results The primary outcome of sustained hemodynamic stability within 24 hours did not differ significantly between the 2 cohorts (achieved in 32% of patients in the low-dose group and 38% in the standard-dose group; P = .65). In-hospital mortality did not differ significantly between groups (48% in the low-dose group vs 45% in the standard-dose group; P = .81). Patients in the low-dose group had fewer days of mechanical ventilation than patients in the standard-dose group (1.5 vs 6 days; P = .03) and a smaller percentage had major bleeding (12% vs 25%; P = .34). Conclusions In patients with high-risk pulmonary embolism, sustained hemodynamic stability within 24 hours did not differ significantly between low-dose and standard-dose alteplase treatment strategies. Low-dose alteplase may be an appropriate alternative dosing strategy for patients with high-risk pulmonary embolism.