Evaluation of endothelial dysfunction and clinical events in patients with early-stage vasculopathy in limited systemic sclerosis

OBJECTIVES: Limited cutaneous systemic sclerosis (lcSSc) is characterised by vasculopathy contributing to vascular apoptosis, structural and functional changes. The aim of this study was to investigate parameters of endothelial dysfunction and their association to clinical events in lcSSc patients with early-stage vasculopathy.

METHODS: Patients with lcSSc and early-stage vasculopathy defined as absent pre-existing pulmonary arterial hypertension (PAH), digital ulcers, and symptomatic cardiovascular diseases were recruited together with age-, race- and sex-matched controls with primary Raynaud's phenomenon. All subjects underwent measurements of flow-mediated (FMD) and nitroglycerine-mediated dilation (NMD), pulse-wave analysis, and biochemical analysis, including arginine, homoarginine, citrulline, ornithine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and endothelial microparticles (EMP). Clinical events, including EUSTAR index, sicca symptoms, microvascular, skin, renal, gastrointestinal, and pulmonary involvement, were recorded by medical history, physical examination, laboratory parameters, disease-specific questionnaire, electrocardiogram, diagnostic imaging and spirometry.

RESULTS: 38 patients with lcSSc and 38 controls were included after screening for eligibility. There was no difference in FMD (p=0.775), NMD (p=0.303), aortic pulse-wave velocity (p=0.662) or in augmentation index (p=0.600) between patients with lcSSc and controls. Higher values of ADMA (p=0.030), SDMA (p=0.025) and borderline significantly higher values for CD31+/CD42b- EMP (p=0.062) were observed in lcSSc patients, also with positive correlations between those parameters. ADMA, SDMA and CD31+/CD42b- were correlated with subclinical PAH, nephropathy and capillary changes.

CONCLUSIONS: Selected parameters of endothelial dysfunction contribute to clinical events in lcSSc patients with early-stage vasculopathy and endothelial dysfunction seems to be primarily present in microvasculature, while its impact on macrovascular changes in lcSSc is still indistinct.