Incidence of pulmonary hypertension and determining factors in patients with systemic sclerosis

The objective of this study was to evaluate the incidence of pulmonary hypertension (PH) and determining factors in patients with systemic sclerosis (SSc) and a diffusing capacity of the lung for carbon monoxide (DLCO) <60% predicted. In this bicentric, prospective cohort study, patients with SSc were clinically assessed at baseline and after 3 years, including right heart catheterisation (RHC). Analysis of determining factors for the development of PH was performed using univariate and multivariate analyses. 96 patients with a mean pulmonary arterial pressure (mPAP) <25 mmHg at baseline were followed for 2.95±0.7 years (median 3 years). Of these, 71 had a second RHC; 18 of these 71 patients (25.3%) developed PH, and five (7%) developed SSc-associated pulmonary arterial hypertension. For patients with an mPAP of 21–24 mmHg at baseline, the likelihood of presenting with PH as opposed to normal pressures on follow-up was significantly higher (p=0.026). Pulmonary vascular resistance, tricuspid regurgitation velocity, diffusion capacity and the size of the inferior vena cava at baseline were independent predictors for the development of PH during follow-up. In a selected cohort of SSc patients with a DLCO <60%, pulmonary pressures appeared to rise progressively during follow-up. In this population, it was possible to identify manifest PH in almost 25% of patients using prospective RHC during follow-up. Therefore, regular clinical assessment including RHC might be useful in patients with SSc.