COMPERA / COMPERA-KIDS

Inclusion Criteria: * All age groups (amendment dated 1 June 2013) * Written informed consent * Pulmonary hypertension (PH) of either * PAH: idiopathic form (IPAH) or * PAH associated with connective tissue diseases (PAH-CTD), with congenital heart defects (PAH-CHD), with HIV infection (PAH-HIV), or the portopulmonary form * Chronic thromboembolic PH (CTEPH) * PH in left heart diseases (with isolated diastolic dysfunction; with systolic dysfunction, other) * PH in pulmonary disease (chronic obstructive pulmonary disease; interstitial fibrosis, etc.) * "Relative PH" in CHD after cavopulmonary anastomosis or Fontan-type surgery, even without the classical pulmonary pressure criteria of PH. * Newly initiated (i.e. a maximum of 3 months before documentation for the first time) therapy with endothelin receptor antagonists (ERA), phoshodiesterase-5 (PDE-5) inhibitors, soluble guanylate cyclase (sGC) stimulators or prostacyclins in mono- or combination therapy. Exceptions: PAH-CHD patients can be included on maintenance or newly initiated PAH therapy (3-month rule dose not apply). PAH-CHD patients with severe pulmonary vascular disease (e.g. Eisenmenger physiology) irrespective of treatment with any PAH drugs are eligible for inclusion, too. Exclusion Criteria: * Patients on maintenance therapy, i.e. previous treatment with any ERA/ PDE-5 inhibitor/prostacyclin/sGC stimulator drug longer than 3 months before documentation for the first time (exception: PAH-CHD patients).