Pulmonary hypertension in interstitial lung disease: an area of unmet clinical need.

Pulmonary hypertension (PH) is present in an important proportion of patients with interstitial lung diseases (ILDs), encompassing a large, heterogeneous group of diffuse parenchymal lung diseases. Development of ILD-related PH is associated with reduced exercise capacity, increased need for supplemental oxygen, decreased quality of life and earlier death. Diagnosis of ILD-related PH is important and requires a high index of suspicion. Noninvasive diagnostic assessment can suggest the presence of PH, although right heart catheterisation remains the gold standard to confirm the diagnosis and to assess its severity. A comprehensive assessment is needed to make sure reversible causes of PH have been ruled out, including thromboembolic events, untreated hypoxaemia and sleep disordered breathing. The results of trials concerning pulmonary vasodilators in this particular patient group have been disappointing and, in some cases, were even associated with an increased risk of harm. Newer strategies such as medications administered through inhalation and combinations with antifibrotic drugs show encouraging results. Moreover, unravelling the role of the vasculature in the pathophysiology of pulmonary fibrosis and ILD-related PH may potentially unlock new therapeutic opportunities.