Date of Award


Document Type


Degree Name

Master of Medical Science (MMSc)

First Advisor

Alfred Lee, MD, PhD


Pulmonary embolism is a potentially fatal disorder in which emboli occlude the pulmonary arteries, thus blocking blood flow to the lungs. As diagnostic imaging becomes more sensitive, a greater number of peripheral pulmonary emboli are detected. It remains unclear whether subsegmental pulmonary emboli, which are smaller and more distal than typical emboli, are clinically significant. In the absence of randomized trials addressing their treatment, controversy exists regarding whether anticoagulation, the standard of care for pulmonary embolism treatment, is warranted. This study will compare anticoagulation versus clinical surveillance in a randomized controlled non-inferiority trial of stable, adult patients with subsegmental pulmonary embolism. We will compare the proportion of patients with venous thromboembolism recurrence over three months in those who receive anticoagulation compared with those who are treated using clinical surveillance. This study will help address the clinical equipoise providers face when managing subsegmental emboli and may help guide future treatment approaches.