Pulmonary arterial hypertension (PAH) is a rare and incurable disease affecting people of all ages. It is characterized by obstructive remodeling of the small pulmonary arteries, responsible for an increase in pulmonary arterial pressure, leading to right heart failure and death in the absence of treatment. PAH can be associated with a variety of diseases, but around half of all PAH cases are idiopathic or hereditary, and may develop on predisposed terrain following a "second hit", as suggested by the identification of PAH cases associated with the use of anorectic drugs, methamphetamine and occupational exposure to organic solvents. No study has systematically analyzed the exposome of patients with PAH, combining environmental and occupational exposures as well as drugs and medications.

The exposome of patients with PAH without associated causes will be compared with that of patients with another form of pulmonary hypertension (PH), linked to thromboembolic risk factors: chronic thromboembolic PH (CTEPH), which will constitute the control group.

Inclusion Criteria:

• Consent signed by the participant

• Age ≥ 18 years

• Free subject, under no legal protection

• Good understanding of the French language, allowing to answer the questionnaires

• Incident patients with pre-capillary PH confirmed by cardiac catheterization (PAPm > 20mmHg, PCP ≤ 15 mmHg, RVP > 2UW) having had the right diagnostic cardiac catheterization within one year (≤1 year) :

  • Cases: Patients with PAH without associated pathology: idiopathic or heritable, or with features of venous/capillary involvement, according to the clinical classification of PH
  • Controls: Patients with chronic thromboembolic PH (CTE-PTH, class 4), according to the clinical classification of PH.

Exclusion Criteria:

• Patients classified as HTP groups 2, 3 or 5
• Patients with a diagnosis of PAH associated with a connective tissue disease, HIV, portal hypertension, congenital heart disease, bilharzia, or a drug or toxic cause considered certain according to the international classification (Aminorex, Benfluorex, Carfilzomib, Dasatinib, Dexfenfluramine, Fenfluramine, Methamphetamines, Mitomycin C, adulterated rapeseed oil)
• Patients with signs of right heart failure requiring amines and/or intensive care hospitalization at time of visit (may be included at a later visit)
• Patients refusing hair sampling or having no hair > 2 cm to allow sampling
• Patients benefiting from enhanced protection, i.e. minors, persons deprived of their liberty by a judicial or administrative decision, persons staying in a health or social establishment, adults under legal protection, and patients in emergency situations

Major patients understanding French language with pre-capillary PH confirmed by cardiac catheterization during the year (PAH without associated pathology and CTEPH class 4)