Condition: Pulmonary embolism


Key Inclusion Criteria

  • 18-75 years old
  • Chest computed tomography angiogram evidence of proximal pulmonary embolism (PE) with a filling defect in at least one main pulmonary artery or lobar artery
  • PE symptom duration ≤14 days 
  • Stroke or transient ischemic attack, head trauma, or other active intracranial or intraspinal disease within 1 year
  • Recent (within 1 month) or active bleeding from a major organ
  • Major surgery within 14 days

Full Study Name

Standard-Dose Apixaban After Very Low-dose Thrombolysis for Acute Intermediate-High Risk Acute Pulmonary Embolism (IRB no. 54951)   


This study focuses on patients who have a blood clot in one or both of their pulmonary arteries (large blood vessels in the chest) that is interfering with blood flow through the heart and lungs. The purpose of the study is to determine how much of a pulmonary embolism (clot) can be dissolved when treated with a very low dose of a thrombolytic drug (clot buster) called alteplase (tPA) along with standard anticoagulant (blood thinning) therapy, compared to standard-of-care anticoagulant therapy alone. tPA is approved by the U.S. Food and Drug Administration (FDA) for breaking down blood clots in pulmonary embolism; however, it is not approved at the dosage the study is using.

Participants will be assigned to one of two study groups. The first group will receive the usual drug to treat pulmonary embolism (heparin) plus a placebo (inactive substance) IV infusion. The second group will receive the usual drug to treat pulmonary embolism (heparin) plus the tPA IV infusion.

Principal Investigator

Victor Tapson, MD

Susan Jackman
Phone: 310-423-4765