Abstract 4383: Incidence of Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis: A 3-Year Longitudinal Study
We have previously determined a prevalence of 7.85% [95%CI: 5.70–10.00] of pulmonary arterial hypertension (PAH) in a large multicentre systemic sclerosis (SSc) population (the ItinerAIR Scleroderma registry). We used a screening algorithm based on dyspnea, Doppler echocardiographic evaluation of the peak velocity of tricuspid regurgitation (VTR) and right heart catheterisation (RHC). No study has determined the incidence of PAH in a large population at risk. To determine the incidence of PAH over 3 years of follow-up in the ItinerAIR SSc registry. Patients underwent regular screening for PAH with Doppler echocardiography confirmed by RHC in patients with VTR of 2.8–3 m/s and unexplained dyspnea, or VTR >3 m/s. 384 patients were followed for a mean of 41±5.6 months (median 41 months). The baseline characteristics of this population were: 87% female, mean age 53±12 years, mean duration of SSc at study entry 8.7±7.6 years, and 24.0% with diffuse SSc. Doppler echocardiography detected PAH in 18 patients (incidence: 1.37 per 100 patient-years). Among these, RHC identified 8 patients with pre-capillary PAH (incidence: 0.61 per 100 patient-years [95%CI: 0.26–1.20]), 8 with post-capillary pulmonary hypertension (PH) and 2 with PH due to severe interstitial lung disease. The 8 patients with pre-capillary PAH had moderate PAH (mean pulmonary pressure: 36±14.6 mmHg). Among the 8 patients with post-capillary PH, echocardiography was always considered normal by the expert cardiologist, except in 2 cases (moderate left atrial dilatation in one and mild aortic sclerosis in the other). These 8 patients had mild post-capillary PH, 5 of them having normal mean pulmonary pressure at rest but a significant increase during exercise with a pulmonary wedge pressure > 15 mmHg. In this large multicentre SSc cohort we prospectively found an incidence of PAH of 0.61 per 100 patient-years. We also demonstrated that RHC is still mandatory to precisely define the type of pulmonary hypertension since mild post-capillary PH without echocardiographic abnormalities are frequent.