Background: Systemic sclerosis (SSc) is one of the frequent causes of the pulmonary arterial hypertension (PAH) which found in 6-15% patient with SSc. Patients with PAH, associated with SSc have a poorer prognosis than other forms of PAH. 6 World Symposium of PH lowered diagnostic cut-off to 21 mm Hg in hope of improved survival. PAH reversibility is described in congenital heart defects, HIV and some tumors

Objectives: The aim of the study to detect reversibility of PAH associated with SSc.

Methods: Hemodynamics (mean pulmonary artery pressure (MPAP), pulmonary artery wedge pressure (PAWP), cardiac output (CO) and pulmonary vascular resistance (PVR)), functional class (NYHA), 6-minute walk distance (6MWD), biomarkers and DLCO were assessed. Patients with pulmonary fibrosis and left heart diseases were excluded.

Results: The study includes 56 patients receiving start-up monotherapy with 1st generation PAH-specific drugs: bosentan (25 patients) and sildenafil (31 patients). The median age of the patients was 51.5 (37; 58) years. At the time of diagnosis, the MPAP in the sildenafil group was 49 (30; 50) mm Hg, bosentan - 50 (42; 56) mm Hg, differences not significant (p = 0.11). During observation against the background of sildenafil intake, the MPAP decreased by -3 (-7; 0) mm Hg, bosentan -6 (-13; -2) mm Hg. Decreasing of MPAP ≤ 21 mm Hg was at seven patients receiving sildenafil. Initial hemodynamic values in this group of patients was MPAP 25 (21; 27) mm Hg., RAP 2 (1; 5) mm Hg, PAWP 7 (6; 10) mm Hg., CV 5.9 (4.7; 6.7) l/min, PVR 3.0 (1.5; 4.2) Wood Unit. Among patients taking sildenafil, there were seven who had MPAP less than 35 mmHg, and among patients taking bosentan, there were 4 patients with less than 35 mmHg. However, the decreasing was observed only group who received sildenafil. ROC – analysis shown that cut-off for reversible is 29 mm Hg (AUC 0,977, sensitivity 97%, and specificity 100%)

Conclusion: In patients with PAH, associated with SSc, on sildenafil treatment, at MPAP < 29 mm Hg reversibility is possible. Further study is required.

Disclosure of Interests: None declared