Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right
heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (
bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like
kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 '
Pulmonary hypertension due to left
heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 '
Pulmonary hypertension due to
respiratory diseases' includes a heterogenous subgroup of
respiratory diseases like PH due to
pulmonary fibrosis,
COPD, lung
emphysema or
interstitial lung disease for exemple. Group 4 includes chronic thromboembolic
pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on
tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The
therapy of PAH consists of non-specific drugs including oral anticoagulation and
diuretics as well as PAH specific
therapy.
Diuretics are one of the most important treatment in the setting of PH because right
heart failure leads to fluid retention, hepatic congestion,
ascites and peripheral
edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2-3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical
therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including
prostanoids (
epoprostenol, trepoprostenil,
iloprost),
endothelin receptor antagonists (
bosentan,
ambrisentan) and
phosphodiesterase type 5 inhibitors (
sildenafil,
tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH
therapy is discussed as well as future treatments.