The purpose of this study is to evaluate the long-term impact of Pulmonary Embolism (PE) on heart and lung function, quality of life, ability to work, symptoms of breathlessness and functional status of patients one year after their initial diagnosis and treatment for PE

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

Patients seen in the Emergency Department, in-patient wards, out-patient clinics or anticoagulation clinics.