Endothelial function and hemodynamics in systemic sclerosis

Systemic sclerosis (SSc) is characterized by the development of fibrosis of skin and internal organs that is associated with vascular damage. However, its related parameters have not been fully explored. The aim of this study was to investigate endothelial function in SSc and its relationship with systolic pulmonary artery pressure and systemic arterial compliance (SAC).

We studied 14 SSc females (4 with diffuse and 10 with limited cutaneous form of the disease) and 14 healthy controls matched for age and for cardiovascular risk factors. Endothelium-dependent dilation (i.e. flow-mediated) and endothelium-independent (i.e. nitroglycerin-induced) dilation of the brachial artery were measured as the percentage of change from baseline (FMD and NMD, respectively). In patients with SSc, SAC, cardiac output (CO), systemic arterial resistance and pulmonary artery pressure were estimated using echocardiography Doppler.

Heart rate, brachial artery pressure and body mass index did not differ between patients with SSc and controls. Flow-mediated vasodilation (FMD) and NMD were significantly decreased in patients with SSc (10.3 ± 8.6 versus 26.6 ± 7.4%, P<0.001; 24.2 ± 8.4 versus 33.3 ± 10.1%, P<0.001, respectively). Postischaemia reactive hyperaemia was lower in patients with SSc (275 ± 185 versus 618 ± 366%, P<0.001). FMD and nitrate-mediated dilation (NMD) were associated with CO, but not with SAC; moreover, FMD correlated with pulmonary artery pressure and peripheral arterial resistance conversely to NMD.

Endothelium function in SSc is impaired independently to SAC. Furthermore, the severity of both small artery and pulmonary artery involvement may impact on endothelium-dependent function.