Pulmonary arterial hypertension in systemic sclerosis: the need for early detection and treatment

Pulmonary arterial hypertension (PAH) is an important cause of mortality in systemic sclerosis (SSc). The symptoms are non-specific and can be ascribed to other features of the disease, so it is often underrecognized until the late stages. Earlier treatment with new agents is associated with better treatment outcomes. The aim of this article is to develop evidence-based guidelines for screening for PAH and interstitial lung disease (ILD) in SSc. PAH occurs in up to 27% of patients with SSc. Abnormal pulmonary function, particularly a disproportionate fall in carbon monoxide diffusing capacity (DLCO), can identify patients in the early stages of PAH, prompting further investigation in high-risk patients (limited SSc of >10 years' duration, symptoms and/or signs of PAH, DLCO <50% predicted, a rapid or large fall in DLCO without evidence of ILD and/or estimated systolic pulmonary artery pressure >45 mmHg on echocardiography). Right heart catheter remains the diagnostic gold standard. An algorithm for screening with regular pulmonary function tests for the early detection of PAH and ILD in SSc is proposed.