Participants will be in three groups- those with lower extremity DVT, those with PE, or those with both lower extremity DVT and PE. Patients will have blood drawn for thrombin generation assay, thromboelastography assay, and thromboinflammatory panel in addition to standard of care labs for diagnosis of VTE and management of anticoagulation. The patients will then fill out questionnaires on quality of life and level of exercise at their first outpatient visit 4 weeks after diagnosis. At approximately 3-6 months after diagnosis, patients will undergo two days of testing for the research study. All patients will have exercise testing using bicycle ergometry to measure global aerobic fitness. They will once again fill out questionnaires about their quality of life and level of physical activity. After a 24 hour rest period, DVT patients will undergo 31P-MR Spectroscopy and non-invasive spin labeling MRI to provide data on skeletal muscle bioenergetics (phosphocreatine metabolism), and lymphatic and venous flow respectively in the affected leg compared to the unaffected leg. This will allow each patient to be his or her own control. After these research procedures, patients will continue to receive standard of care treatment for their VTE in the Bleeding and Thrombosis clinic.
