• Rare lung diseases
• Not Applicable

Pulmonary hypertension (PH) is a feared complication in patients with any chronic lung disease,1 but those with lung fibrosis have an especially poor mortality and the morbidity burden is very high.2 3 Up to very recently, there has been an almost nihilistic attitude towards these patients, since the lack of treatment options restricted the indication of a definitive diagnosis through right heart catheterisation (RHC) to lung transplant evaluation and enrolment in a clinical trial.4 Although with sound rationale, randomised placebo-controlled trials (RCT) with pulmonary vasodilators, have been negative or at worse detrimental5 (figure 1). That was until recently. The INCREASE study6 was the first double-blind RCT that had a positive outcome with respect to primary outcome (6-minute walking distance) as well as an improvement in brain natriuretic peptide levels and reduced clinical worsening events. Patients, with a wide range of underlying interstitial lung diseases (ILDs) and RHC-diagnosed PH, received 16 weeks of inhaled treprostinil up to nine doses a day compared with placebo. Furthermore, in an open-label extension (OLE) study, benefits were seen up to 52 weeks including a reduction in ILD exacerbations.7 Other post hoc studies have shown a dose dependent improvement8 and that patients receiving treprostinil are less likely to experience further disease progression events after an initial event.9