Pulmonary Hypertension in Parenchymal Lung Diseases: Any Future for New Therapies?
Pulmonary hypertension (PH) due to chronic lung disease is associated with a poor prognosis, regardless of the underlying respiratory condition. Updated PH guidelines recommend optimal treatment of the underlying lung disease, including long-term oxygen therapy, in patients with chronic hypoxemia despite the lack of randomized controlled clinical trials supporting this statement. So far, randomized controlled trials of drugs approved for pulmonary arterial hypertension have yielded discouraging results in both interstitial lung diseases and COPD with PH. In some cases, the trials were terminated because of an increase in death and other major adverse events in the active treatment arm vs placebo. In cases of PH due to idiopathic pulmonary fibrosis, new therapies under investigation use a combination of novel antifibrotic treatments and other treatments approved for pulmonary arterial hypertension. The choice of robust end points as well as a target group of patients with specific hemodynamic criteria may help in the selection of innovative therapeutic strategies. The aim of this review is to discuss recent studies and clinical trials for the treatment of PH due to the main chronic respiratory diseases and to discuss possible future scenarios for the evaluation of new therapeutic strategies.