U.S. CTEPH Registry

Inclusion Criteria: * Patients must be a permanent resident of the United States * Documentation of the following hemodynamic parameters by right heart catheterization * Mean pulmonary arterial pressure (PAPm) ≥ 25 mm Hg at rest and, * Pulmonary artery wedge pressure (PAWP) ≤ 15 mm Hg (or \> 15 mmHg if justified) * Radiologic confirmation that chronic thromboembolic disease is the cause of the pulmonary hypertension by * One or more mismatched perfusion defect(s) by lung ventilation/perfusion scan, and * Confirmation of chronic thromboembolic disease by evidence of bands/webs, vessel narrowing or occlusion seen on CT pulmonary angiogram (CTA), conventional angiography or MR angiography (MRA). * Patients must be diagnosed with CTEPH within 6 months of being considered for study eligibility (signing of consent to participate). The date of diagnosis will be defined as when both hemodynamic criteria have been met and chronic thromboembolic disease is confirmed to be the cause of the pulmonary hypertension by an abnormal V/Q scan and the presence of chronic thromboembolic disease on CTA, MRA or pulmonary angiography. Hemodynamic and radiologic criteria can be met at separate time points; the most recently met criteria time point will be defined as the date of diagnosis. * Prior to enrollment all subjects must have the diagnosis of CTEPH confirmed by the Adjudication Committee. Exclusion Criteria: * Patients unwilling or unable to provide written consent for participat…