Effects of prostaglandin E1alpha cyclodextrin [corrected] treatment on endothelial dysfunction in patients with systemic sclerosis

Flow Mediated Dilation in Systemic Sclerosis: Association with clinical findings, capillaroscopic patterns and endothelial circulating markers

AIM

Endothelial dysfunction represents a key feature of the pathological process underlying micro and macro-vascular damage in Systemic Sclerosis (SSc). This study aims to improve knowledge of the physiopathology of vascular damage in SSc through the assessment of the endothelial dysfunction by Flow Mediated Dilation (FMD) and serum levels of circulating endothelial dysfunction markers and the correlation of macrovascular damage with clinical findings and microvascular capillaroscopic patterns.

METHODS

57 SSc patients and 37 healthy subjects were recruited. All included subjects underwent radial artery FMD test and Nailfold Video-Capillaroscopy; serum levels of Vascular Endothelial Growth Factor (VEGF), Vascular Cell Adhesion Molecule-1 (VCAM-1) and angiopoietin-2 were evaluated.

RESULTS

Compared to healthy subjects, in SSc patients lower FMD and higher time needed to obtain the maximal FMD responsewere observed, whereas serum levels of VEGF, VCAM-1, and angiopoietin-2 were significantly higher. The impairment of FMD values was associated with disease duration, pulmonary arterial hypertension, and digital ulcers and correlates with greater microvascular damage evaluated by Nailfold Video-Capillaroscopy… An inverse relationship between VEGF, angiopoietin-2, VCAM-1 levels and FMD was observed, but only VEGF and angiopoietin-2 were significantly higher in patients with digital ulcers and pulmonary arterial hypertension.

CONCLUSIONS

FMD ultrasound test and circulating levels of endothelial dysfuncion markers could be useful as biomarkers of vasculopathy and could be a helpful tool in the overall assessment of vascular injury in Systemic Sclerosis patients.

Vasculopathy in scleroderma

Systemic sclerosis (SSc) is a multisystem connective tissue disorder featured by vascular injury and fibrosis of the skin and various internal organs with autoimmune background. Although the pathogenesis of SSc still remains elusive, it is generally accepted that initial vascular injury due to autoimmunity and/or environmental factors causes structural and functional abnormalities of vasculature which eventually result in the constitutive activation of fibroblasts in various organs. Structural alterations consist of destructive vasculopathy (loss of small vessels) and proliferative obliterative vasculopathy (occlusion of arterioles and small arteries with fibro-proliferative change) caused by impaired compensatory vasculogenesis and angiogenesis. Impaired function of SSc vasculature includes the altered expression of cell adhesion molecules predominantly inducing Th2 and Th17 cell infiltration, endothelial dysfunction primarily due to the low availability of nitric oxide, the activated endothelial-to-mesenchymal transition leading to fibro-proliferative vascular change and tissue fibrosis, and the impaired coagulation/fibrinolysis system promoting the formation of intravascular fibrin deposits. Recent new insights into the therapeutic mechanisms of intravenous cyclophosphamide pulse and bosentan and the establishment of a new SSc animal model (Klf5 (+/-);Fli1 (+/-) mice) provide us useful clues to further understand the development of vascular alterations characteristic of SSc. This article overviewed the present understanding of the pathogenesis of SSc vasculopathy.

Systemic sclerosis induces pronounced peripheral vascular dysfunction characterized by blunted peripheral vasoreactivity and endothelial dysfunction

Systemic sclerosis (SSc) vasculopathy can result in a digital ulcer (DU) and/or pulmonary arterial hypertension (PAH). We hypothesized that bedside brachial artery flow-mediated dilation (FMD) testing with duplex ultrasound could be used in SSc patients to identify features of patients at risk for DU or PAH. Thirty-eight SSc patients were compared to 52 age-matched healthy controls from the VAMC Utah Vascular Research Laboratory. Peripheral hemodynamics, arterial structure, and endothelial function were assessed by duplex ultrasound. A blood pressure cuff was applied to the forearm and 5-min ischemia was induced. Post-occlusion, brachial artery vascular reactivity (peak hyperemia/area under the curve [AUC]), shear rate, and endothelial function (FMD) were measured. SSc patients had smaller brachial artery diameters (p < 0.001) and less reactive hyperemia (p < 0.001), peak shear rate (p = 0.03), and brachial artery FMD (p < 0.001) compared with healthy controls. Brachial artery FMD was lower (p < 0.05) in SSc patients with DU. Tertile analysis suggested the 2 lower FMD tertiles (<5.40 %) had a 40-50 % chance of presenting with DU while the SSc patients with highest FMD tertile (>5.40 %) had less than 15 % chance of DU. All brachial artery FMD measurements were similar between SSc patients with and without PAH (all p > 0.05). Compared to healthy controls, SSc patients had significantly smaller brachial artery diameter and blunted peripheral vascular reactivity and endothelial function. SSc patients with DU have even greater impairments in endothelial function compared to those without DU. FMD testing has clinical utility to identify SSc patients at risk for DU.

Clinical correlation of brachial artery flow-mediated dilation in patients with systemic sclerosis

OBJECTIVE: To investigate the clinical significance of flow-mediated dilation (FMD) in systemic sclerosis (SSc). METHODS: Thirty-three SSc patients and 12 healthy controls were studied. Ultrasound assessment of the brachial artery FMD was performed on all subjects. The results were expressed as the percentage of increase in brachial artery diameter following hyperemia. RESULTS: Limited cutaneous SSc (lcSSc) patients had significantly lower FMD values than healthy controls (5.3 ± 2.7 versus 7.7 ± 2.0 %, p < 0.05), while the values in diffuse cutaneous SSc (dcSSc) patients (6.7 ± 4.0 %) were comparable to those in lcSSc patients and healthy controls. Although FMD values did not correlate with any clinical features in dcSSc patients, there was an inverse correlation between FMD values and disease duration in lcSSc patients (r = -0.64, p < 0.05). Furthermore, lcSSc patients with decreased FMD values showed significantly higher prevalence of digital ulcers and elevated right ventricular systolic pressure than those with normal values (for each; 75 versus 10 %, p < 0.05). CONCLUSION: The FMD values represent the severity of vascular damages, which progress along with disease duration and lead to digital ulcers and pulmonary arterial hypertension, in lcSSc patients.

Effect of hyperbaric oxygen on flow-mediated vasodilation: an ultrasound study

OBJECTIVE

The purpose of this study was to investigate the effect of hyperbaric oxygen (HBO) treatment on flow-mediated vasodilation (FMD) by ultrasound examination.

METHODS

We studied 14 young patients without cardiovascular problems who underwent HBO treatment. The indications for HBO treatment were osteomyelitis (n = 8), Crohn disease (n = 2), perianal abscesses (n = 2), lingual artery embolization (n = 1), and aseptic necrosis (n = 1). The ultrasound evaluation for FMD was performed before HBO treatment, after 1 session of HBO treatment, and after 10 sessions of HBO treatment. The right brachial artery FMD response was evaluated by the mean of the baseline right brachial artery diameter, absolute change in the diameter before and after cuff inflation/deflation, and percent change in the diameter.

RESULTS

Statistical analysis showed a significant change in the preinflation right brachial artery diameter before (mean +/- SD, 3.6 +/- 0.54 mm) and after (3.76 +/- 0.56 mm) 10 sessions of HBO treatment (P < .05). The absolute changes in the right brachial artery diameter before and after cuff inflation/deflation (0.36 +/- 0.2 mm before HBO treatment, 0.37 +/- 0.22 mm after 1 session of HBO treatment, and 0.38 +/- 0.21 mm after 10 sessions) and percent change in FMD (10% +/- 5.8% before HBO treatment, 10.6% +/- 7.5% after 1 session of HBO treatment, and 10.6% +/- 7.7% after 10 sessions) after induction of a hyperemic response by cuff inflation were not statistically significant (P > .05).

CONCLUSIONS

Hyperbaric oxygen treatment did not have an immediate effect on FMD (absolute change in the right brachial artery diameter after cuff inflation/deflation); however, the right brachial artery diameter increased after 10 sessions of HBO treatment. This may suggest chronic stress on the vascular endothelium after HBO.