Pulmonary hypertension in systemic sclerosis: prevalence, incidence and predictive factors in a large multicentric Italian cohort

Objectives. This paper aims to investigate the prevalence, the incidence of pulmonary hypertension (PH) and its subtypes in Italian patients with systemic sclerosis (SSc) and to characterise features associated with and predictive of development of PH. Methods. Eight-hundred and sixty-seven consecutive SSc patients recruited at 4 Italian centres were enrolled. At admission, all patients underwent a careful history, physical examination, EKG, lung high resolution computed tomography (HRCT), pulmonary function tests, B-mode echocardiography and right heart catheterisation (RHC), if indicated. Patients were then visited every 6-12 months. A RHC was performed in those patients in whom PH was suspected for the presence of pre-specified criteria. Results. Among the 212 patients in whom it was suspected, PH was confirmed by RHC in 69 patients. On 31st December 2010, the point prevalence of P-arterial-H(PAH) and PH associated with interstitial lung disease (PH-ILD) was 3.7% and 1.4%, respectively; that of postcapillary PH was 13%. The estimated incidence rates of PH and PAH were respectively 1.85/100 patient-years and 1.02/100 patient-years. Multivariate analysis indicated that diffusing lung capacity for CO (DLCO) <= 55% (HR 4.45, 95%CI 224-8.83; p<0.001) and sPAP >40 mmHg (HR 18.03, 95%CI 9.01-36.06; p<0.001) were associated with an increased risk to develop PAH. SystolicPAP >40 mmHg resulted the only predictor of PH-ILD (HR 5.17, 95%CI 1.37-19.5; p=0.018) and post-capillary PH (HR 7.91, 95%CI 1.88-33.1; p=0.005) development. Conclusion. Our study confirms a lower prevalence of PH in Italy compared to Anglo-Saxon cohorts. We also identified patients at high risk, who should be carefully monitored.