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.