Pulmonary hypertension in the course of diffuse parenchymal lung diseases - state of art and future considerations

Lung diseases are one of the most frequent causes of pulmonary hypertension (PH). The development of PH influences the course of lung disease, worsening the clinical symptoms and prognosis. According to the most recent publications, PH in the course of lung diseases develops as a result of both "parenchymal" and vascular pathology, in the patients with genetic predisposition. Prolonged infection (especially viral one) may be an additional promoting factor. Right heart catheterization (RHC), which is an invasive procedure, is the only objective method of diagnosing PH. According to the latest recommendations, the management algorithm of PH and coexisting interstitial lung disease is based on RHC and the results of pulmonary function tests. Majority of the patients develop mild PH in the course of advanced lung disease. Best treatment of underlying lung pathology combined with long term oxygen treatment is recommended in this group. In case of severe PH (mean resting pulmonary artery pressure (mPAP) ≥ 35 mm Hg) the alternate cause of PH has to be sought. PAH-specific drugs use should be limited to patients with severe PH participating in clinical trials. In this review, the value of various non-invasive methods (echocardiography, radiological examination, exercise capacity and brain natriuretic peptides assessment) in the process of screening for PH is presented, and the results of recent randomized clinical trials with PAH-specific drugs in patients with diffuse parenchymal lung diseases are discussed.