A Study of Mobility Outcomes in Post-Pulmonary Embolic Disease

Inclusion Criteria: Acute intermediate-risk PE, defined as: * Intraluminal filling defect in segmental or larger vessels on computed tomography pulmonary angiography or high-probability ventilation/perfusion scan AND * Evidence of right ventricular enlargement by computed tomography (RV to LV ratio \>1) or echocardiography; and/or right ventricular dysfunction by transthoracic echocardiography. These imaging characteristics must be in the setting of acute PE rather than explained by a prior chronic condition. Acute high-risk PE, defined as: * Intraluminal filling defect in segmental or larger vessels on computed tomography pulmonary angiography or high-probability ventilation/perfusion scan AND * Evidence of right ventricular enlargement by computed tomography (RV to LV ratio \>1) or echocardiography; and/or right ventricular dysfunction by transthoracic echocardiography. These imaging characteristics must be in the setting of acute PE rather than explained by a prior chronic condition; AND * Hypotension (systolic blood pressure \< 90 mm Hg sustained for more than 15 minutes; or requiring vasopressors) or cardiogenic shock due to acute pulmonary embolism. Exclusion Criteria: * Inability to ambulate independently, which is necessary to perform 6MWD (may be self-reported or as deemed by physical therapy during inpatient evaluation). * If patient requires supplemental oxygen during ambulation, this does not exclude patient from participation and will be noted during eCRF. * Prior history of pulmonary embolism * History of CTEPH or pulmonary arterial hypertension * Unable to read a questionnaire in English * Unable to return for baseline, 3- or 6-month follow-up visit * Pregnancy-associated pulmonary embolism * Life expectancy \<1 year based on comorbidities * Unable/unwilling to provide informed written consent