Female and male patients ≥ 18 years of age, diagnosed with CTEPH regardless of the current treatment

Availability of a signed informed consent

WHO Pulmonary Hypertension clinical classification Group IV (CTEPH):

1. Right heart catheterization (RHC) results that are in line with both of the following haemodynamic levels:

* Mean pulmonary arterial pressure (PAP) ≥ 25 mmHg at rest

* Pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg

2. Confirmation of CTEPH diagnosis by one of the following as recommended by standard guidelines:

* At least 1 (segmental) perfusion defect(s) in ventilation/perfusion (V/Q) scan or

* Pulmonary artery obstruction seen by MDCT (multidetector computed tomography) angiography or

* Pulmonary artery obstruction seen by conventional pulmonary cineangiography (In case of suspicion/diagnosis of 'sub-acute' Pulmonary Embolism: Patients who are treated with anti-coagulation for at least 3 months before diagnosis of CTEPH)

A Study Investigating Routine Practice of Chronic Thromboembolic Pulmonary Hypertension Management in EMEA Countries

What this study is about