Blood flow in the hands of a predefined homogeneous systemic sclerosis population: The presence of digital ulcers and the improvement with bosentan

Abstract

Objectives. The aim of the study was to examine the effect of bosentan on blood flow in the hand in a subset of patients who had reduced blood flow relative to healthy subjects. Additionally, the relationship between blood flow in the hands of SSc patients and the presence of digital ulcers (DUs) was assessed. Methods. SSc patients with a recent history of DUs and healthy subjects were included. Patients were classified into four subgroups: no current DUs or pitting scars, pitting scars only, new DUs or persistent DUs. The hand was categorized into three regions of interest (ROIs) and blood flow was measured by laser Doppler perfusion imaging at baseline, 4 and 12 weeks. Patients who had a reduction in blood flow of >50% relative to healthy control subjects in ROI 1 on baseline were treated with bosentan for 12 weeks. Results. Fifty-two SSc patients and 51 healthy subjects were included in the analysis. There was no significant difference in blood flow in the hand across the patient subgroups at baseline. Sixteen SSc patients had a reduction of blood flow of ≥50% vs healthy subjects and received bosentan. Bosentan significantly (P<0.05) increased blood flow in the whole hand after 12 weeks compared with baseline. Conclusion. No relationship was found between blood flow in the hands and the presence of DUs. After 12 weeks of bosentan treatment, blood flow had increased in the SSc patients but had not normalized to that of healthy subjects.