Prospective Evaluation of Long-term Outcomes After Pulmonary Embolism

Inclusion Criteria: 1. First episode of acute symptomatic PE that was objectively diagnosed\* within last 10 days 2. Treated with anticoagulants 3. ≥ 18 years old * PE will be diagnosed if there is a high probability V/Q scan (as per PIOPED Study criteria 66), an intraluminal filling defect in segmental or larger vessels on CTPA or a constant intraluminal filling defect or abrupt cut-off of vessels greater than 2.5 mm diameter on pulmonary angiography 8,10. Patients with non-definitive test results (e.g. low or intermediate probability V/Q scan, subsegmental PE on CTPA (\~5% of PE patients 12) will not be included in order to have a strictly defined population of patients with definite PE. Exclusion Criteria: 1. Contraindication or unable to perform CPET or 6MWT (amputated or paralyzed limb(s), severe lower extremity arthritis, preexisting cardiopulmonary condition precluding exercise including unstable angina or myocardial infarction in last 6 weeks, uncontrolled hypertension, serious cardiac dysrhythmia on resting EKG \[severe bradycardia or tachycardia, sick sinus syndrome or multifocal premature ventricular contractions\] and syncope) 2. Contraindication to CTPA (allergy to iodinated contrast, CrCl or eGFR \< 30 ml/min) 3. Severe comorbidity (congestive heart failure \[LVEF \< 35%\], severe COPD or restrictive lung disease \[FEV1\<50%, chronic need for oxygen therapy\]) 4. Previous DVT (as \~40% of patients with proximal DVT have asymptomatic PE on lung imaging 67) 5. Life expectancy \< 1 year (e.g. active or terminal cancer, end-stage cardiac or respiratory disease). 6. Pregnancy or lactation 7. Unable to read questionnaire in English or French 8. Unable to return to study centre for required follow-up visits 9. Unable or unwilling to provide written informed consent