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

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.

Glycocalyx-targeted therapy ameliorates age-related arterial dysfunction

Advanced age is accompanied by arterial dysfunction, as well as a diminished glycocalyx, which may be linked to reduced high molecular weight-hyaluronan (HMW-HA) synthesis. However, the impact of glycocalyx deterioration in age-related arterial dysfunction is unknown. We sought to determine if manipulations in glycocalyx properties would alter arterial function. Tamoxifen-induced hyaluronan synthase 2 (Has2) reduction was used to decrease glycocalyx properties. Three weeks post-tamoxifen treatment, glycocalyx thickness was lower in Has2 knockout compared to wild-type mice (P<0.05). Has2 reduction induced arterial dysfunction, demonstrated by impaired endothelium-dependent dilation (EDD) and elevated aortic stiffness (P<0.05). To augment glycocalyx properties, old mice received 10 weeks of a glycocalyx-targeted therapy via Endocalyx™ (old+ECX), which contains HMW-HA and other glycocalyx components. Compared to old control mice, glycocalyx properties and EDD were augmented, and aortic stiffness decreased in old+ECX mice (P<0.05). Old+ECX mice had a more youthful aortic phenotype, demonstrated by lower collagen content and higher elastin content than old control mice (P<0.05). Functional outcomes were repeated in old mice that underwent a diet supplemented solely with HMW-HA (old+HA). Compared to old controls, glycocalyx properties and EDD were augmented, and aortic stiffness was lower in old+HA mice (P<0.05). We did not observe any differences between old+HA and old+ECX mice (P>0.05). Has2 reduction phenocopies age-related arterial dysfunction, while 10 weeks of glycocalyx-targeted therapy that restores the glycocalyx also ameliorates age-related arterial dysfunction. These findings suggest that the glycocalyx may be a viable therapeutic target to ameliorate age-related arterial dysfunction.

High-salt diet augments systolic blood pressure and induces arterial dysfunction in outbred, genetically diverse mice

Excess salt consumption contributes to hypertension and arterial dysfunction in humans living in industrialized societies. However, this arterial phenotype is not typically observed in inbred, genetically identical mouse strains that consume a high-salt (HS) diet. Therefore, we sought to determine the effects of HS diet consumption on systolic blood pressure (BP) and arterial function in UM-HET3 mice, an outbred, genetically diverse strain of mice. Male and female UM-HET3 mice underwent a low-salt [LS (1% NaCl)] or HS (4% NaCl) diet for 12 wk. Systolic BP and aortic stiffness, determined by pulse wave velocity (PWV), were increased in HS after 2 and 4 wk, respectively, compared with baseline and continued to increase through week 12 (P < 0.05). Systolic BP was higher from weeks 2-12 and PWV was higher from weeks 4-12 in HS compared with LS mice (P < 0.05). Aortic collagen content was ∼81% higher in HS compared with LS (P < 0.05), whereas aortic elastin content was similar between groups (P > 0.05). Carotid artery endothelium-dependent dilation (EDD) was ∼10% lower in HS compared with LS (P < 0.05), endothelium-independent dilation was similar between groups (P > 0.05). Finally, there was a strong relationship between systolic BP and PWV (r2 = 0.40, P < 0.05), as well as inverse relationship between EDD and systolic BP (r2 = 0.21, P < 0.05) or PWV (r2 = 0.20, P < 0.05). In summary, HS diet consumption in UM-HET3 mice increases systolic BP, which is accompanied by aortic stiffening and impaired EDD. These data suggest that outbred, genetically diverse mice may provide unique translational insight into arterial adaptations of humans that consume an HS diet.NEW & NOTEWORTHY Excess salt consumption is a contributor to hypertension and arterial dysfunction in humans living in industrialized societies, but this phenotype is not observed in inbred, genetically identical mice that consume a high-salt (HS) diet. This study reveals that a HS diet in outbred, genetically diverse mice progressively increases systolic blood pressure and induce arterial dysfunction. These data suggest that genetically diverse mice may provide translational insight into arterial adaptations in humans that consume an HS diet.

Brachial artery flow-mediated dilation in patients with systemic sclerosis: an experience from tertiary care center from North India

Role of flow-mediated dilatation (FMD) testing in the assessment of the macrovascular dysfunction in systemic sclerosis (SS) and correlation of FMD values with disease severity. Twenty-five patients of SS and 25 healthy age-matched controls were recruited. Modified Rodnan skin thickness score (MRSS) was used for skin thickness assessment. FMD values were measured in the brachial artery. FMD values done at baseline before the initiation of treatment were lower in SSc patients (4.044 ± 2.742) compared to the healthy controls (11.076 ± 5.896) (P < 0.05). Comparison of FMD values between patients with limited cutaneous systemic sclerosis (LSSc) and diffuse cutaneous systemic sclerosis (DSSc) showed a trend toward lower in LSSc (3.182 ± 2.482) as compared to DSSc patients (5.111 ± 2.711); however, the difference was not statistically significant. Patients with lung manifestations on high-resolution CT chest showed lower FMD values (2.66 ± 2.23) compared to those without HRCT changes (6.45 ± 2.56) (P < 0.05). We demonstrate that FMD values in SSc patients were lower when compared to healthy controls. Patients with SS having pulmonary manifestations showed a lower value of FMD. Key Points • FMD is a simple non-invasive tool to assess the endothelial function in patients with systemic sclerosis. • Lower values of FMD in systemic sclerosis suggest that the endothelial dysfunction and values can also be correlated with other organ involvement such as lung and skin involvement. So, lower FMD values might be a useful marker for disease severity.

Correlation between Microvascular Damage and Internal Organ Involvement in Scleroderma: Focus on Lung Damage and Endothelial Dysfunction

BACKGROUND

Systemic sclerosis (SSc) is an incurable connective tissue disease characterized by decreased peripheral blood perfusion due to microvascular damage and skin thickening/hardening. The microcirculation deficit is typically secondary to structural vessel damage, which can be assessed morphologically and functionally in a variety of ways, exploiting different technologies.

OBJECTIVE

This paper focuses on reviewing new studies regarding the correlation between microvascular damage, endothelial dysfunction, and internal organ involvement, particularly pulmonary changes in SSc.

METHODS

We critically reviewed the most recent literature on the correlation between blood perfusion and organ involvement.

RESULTS

Many papers have demonstrated the link between structural microcirculatory damage and pulmonary involvement; however, studies that have investigated correlations between microvascular functional impairment and internal organ damage are scarce. Overall, the literature supports the correlation between organ involvement and functional microcirculatory impairment in SSc patients.

CONCLUSIONS

Morphological and functional techniques appear to be emerging biomarkers in SSc, but obviously need further investigation.

Novel therapies and innovation for systemic sclerosis skin ulceration

Skin ulceration is an important cause of morbidity in systemic sclerosis and can occur at anytime during disease progression. Incident disease cohorts are important for understanding whether skin ulceration represents active vasculopathy versus resultant damage. Biomarkers for skin ulcer pathogenesis, both serum and imaging, are under investigation to elucidate the functional consequences of the structural abnormalities. Novel therapeutics for the treatment of vasculopathy benefit from reliable biomarkers able to predict the disease evolution remains an important unmet need. Nonetheless, a diagnostic approach that captures early skin ulceration and treatments that restore vascular and immune homeostasis is critical for effective systemic sclerosis (SSc) vasculopathy management.

Tetrahydrobiopterin Administration Augments Exercise-Induced Hyperemia and Endothelial Function in Patients With Systemic Sclerosis

Systemic sclerosis (SSc) is a rare, auto-immune disease with variably progressive fibrosis of the skin and internal organs, as well as vascular dysfunction. Recently, we demonstrated a decrement in exercising skeletal muscle blood flow and endothelium-dependent vasodilation in SSc, but the mechanisms responsible for these impairments have not been investigated. Thus, we sought to determine if acute administration of tetrahydrobiopterin (BH₄), an essential cofactor for endothelial nitric oxide synthase (eNOS), would improve hyperemia and brachial artery vasodilation during progressive handgrip exercise in SSc. Thirteen patients with SSc (63 ± 11 years) participated in this placebo-controlled, randomized, double-blind, crossover study. Tetrahydrobiopterin (10 mg/kg) administration resulted in a ~4-fold increase in circulating BH₄ concentrations (P < 0.05). Cardiovascular variables at rest were unaffected by BH₄ (P > 0.05). During handgrip exercise, BH₄ administration increased brachial artery blood flow (placebo: 200 ± 87; BH₄: 261 ± 115 ml/min; P < 0.05) and vascular conductance (placebo: 2.0 ± 0.8; BH₄: 2.5 ± 1.0 ml/min/mmHg; P < 0.05), indicating augmented resistance artery vasodilation. Tetrahydrobiopterin administration also increased brachial artery vasodilation in response to exercise (placebo: 12 ± 6; BH₄: 17 ± 7%; P < 0.05), resulting in a significant upward shift in the slope relationship between Δ brachial artery vasodilation and Δ shear rate (placebo: 0.030 ± 0.007; BH₄: 0.047 ± 0.007; P < 0.05) that indicates augmented sensitivity of the brachial artery to vasodilate to the sustained elevations in shear rate during handgrip exercise. These results demonstrate the efficacy of acute BH₄ administration to improve both resistance and conduit vessel endothelial function in SSc, suggesting that eNOS recoupling may be an effective strategy for improving vasodilatory capacity in this patient group.

Peripheral microcirculatory abnormalities are associated with cardiovascular risk in systemic sclerosis: a nailfold video capillaroscopy study

INTRODUCTION

Microvascular dysfunction is the key element in the pathogenesis of systemic sclerosis (SSc), whereas the contribution of large and medium size vessel abnormalities is yet to be established. The aim of the present study is to assess the association between micro- and macrovascular function by utilizing a broad spectrum of assessments of vascular performance.

METHODS

We included consecutive, consenting SSc patients who underwent nailfold video capillaroscopy (NVC) for microcirculation evaluation. Peripheral and central systolic and diastolic blood pressure, carotid intima-media thickness (cIMT), aortic augmentation index (AIx) corrected for a heart rate of 75 beats per minute (AIx-75), and carotid-femoral pulse wave velocity (PWV) were also performed to assess macrovascular function. Cardiovascular risk disease (CVD) algorithms were also calculated and included in the analysis.

RESULTS

A total of 81 patients (6 males) were studied with mean age 55.44 ± 13.40 years. Reduced capillary density was inversely correlated with arterial stiffness (Alx-75) and augmentation pressure (r =  - 0.262, p = 0.018, and r =  - 0.249, p = 0.025 respectively). Alx was significantly lower in the early compared to late pattern (28.24 ± 11.75 vs 35.63 ± 10.47, p = 0.036). A significant trend was found among NVC patterns with Alx-75 values being higher with the progression of microangiopathy towards the "late" group (26.36 ± 10.90 vs 30.81 ± 11.59 vs 35.21 ± 7.90, p = 0.027 for trend). Similarly, Framingham risk score and Atherosclerotic Cardiovascular Disease score were progressively higher across the worsening NVC patterns (4.10 ± 4.13 vs 2.99 ± 2.72 vs 6.36 ± 5.65, p = 0.023, and 6.99 ± 7.18 vs 5.63 ± 4.41 vs 12.09 ± 9.90, p = 0.019, respectively, for trends). Finally, QRISK3 (10-year cardiovascular disease risk) and ASCVD (Atherosclerotic Cardiovascular Disease) scores were inversely correlated with the number of capillaries (r =  - 0.231, p = 0.048, and r =  - 0.260, p = 0.038 respectively).

CONCLUSION

These data suggest that CVD risk scores and macrovascular parameters are strongly correlated with microvasculopathy in patients with SSc. Key Points • Microangiopathy is the hallmark of SSc, but the relationship between subclinical atherosclerosis and small vessel disease remains unknown. • Arterial stiffening and CVD risk scores are positively associated with the degree of progression of peripheral microvasculopathy assessed with NVC. • The results of the study suggest an association between NVC abnormalities and higher CVD risk in SSc patients.

Vascular endothelial injury assessed with functional techniques in systemic sclerosis patients with pulmonary arterial hypertension versus systemic sclerosis patients without pulmonary arterial hypertension: a systematic review and meta-analysis

Microvascular dysfunction is one of the hallmarks of systemic sclerosis (SSc). The presence of pulmonary-arterial-hypertension (PAH) in SSc-patients is associated with poor prognosis. This is a systematic review and meta-analysis of studies assessing microvascular and endothelial injury with functional techniques in SSc-patients with PAH (SSc-PAH) compared to those without PAH (SSc-non-PAH) (PROSPERO: CRD42021236212). Literature search involved PubMed, the-Cochrane-Library, Web-of-Science, Scopus and manual search of article references. Studies assessing microvascular function by all available functional methods were considered eligible. Preclinical studies and studies using structural nailfold-videocapillaroscopy or biomarkers were excluded. Newcastle-Ottawa-Scale (NOS) was applied to evaluate the quality of retrieved studies. From a total of 602 retrieved articles, four studies (n = 159 participants) were included in meta-analysis; three studies were of high quality (NOS ≥ 7). In pooled analysis, a marginally significant impaired microvascular function was observed in SSc-PAH compared to SSc-non-PAH patients [SMD - 0.71, 95% CI (- 1.53, 0.12)], with significant between-study heterogeneity (I² = 80%, p = 0.002). Among the studies examining endothelium-dependent and -independent vasodilation with LDF-iontophoresis, SSc-PAH subjects had significantly impaired endothelium-dependent-vasodilation [Ach-stimulated %change WMD - 216.79, 95% CI (- 337.87, - 95.71), I² = 0%, p = 0.40], but no significant differences in endothelium-independent-vasodilation [SNP-stimulated %change WMD 90.84, 95% CI (- 82.52, 264.19), I² = 44%, p = 0.18] compared with SSc-non-PAH subjects. In sensitivity analysis including only studies where SSc-PAH patients were diagnosed by right-heart-catheterization, a borderline difference between the two groups was noted [SMD - 1.09, 95% CI (- 2.30, 0.13), I² = 82%, p = 0.004]. SSc-PAH patients showed marginally impaired microvascular function in the pooled analysis, as well as impaired endothelium-dependent-vasodilation in subgroup analysis compared with SSc-non-PAH patients. Vascular endothelial dysfunction could be involved in high cardiovascular risk of patients with SSc and PAH.

Systemic sclerosis and risk of cardiovascular disease: A PRISMA-compliant systemic review and meta-analysis of cohort studies

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disorder leading to extensive fibrosis and microvascular injury. Macrovascular disease is well documented in other autoimmune rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis. However, the link is unclear between SSc and macrovascular disease, particularly atherosclerotic cardiovascular disease (CVD). This meta-analysis aimed to investigate the association between SSc and CVD.

METHODS

A thorough literature search was conducted in the Cochrane, Embase, Medline, and PubMed to identify all cohort studies comparing the risk of CVD with and without SSc. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of cardiovascular end points were calculated. The risk of bias of included studies was assessed by the Newcastle-Ottawa scale.

RESULTS

Seven cohort studies with a total of 14,813 study participants were included. In a comparison of SSc patients versus non-SSc controls, the pooled HR for cardiovascular disease was 2.36 (95% CI 1.97-2.81); for peripheral vascular disease was 5.27 (95%CI 4.27-6.51); for myocardial infarction was 2.36 (95% CI 1.71-3.25); and for stroke was 1.52 (95% CI 1.18-1.96).

CONCLUSION

This meta-analysis revealed that SSc was associated with an increased risk of CVD. Clinicians who manage patients with SSc should be aware of the increased cardiovascular burden and undertake preventive measures.

Raynaud Phenomenon in Systemic Sclerosis: Does Digital Thermal Monitoring Correlate to Specific Nailfold Videocapillaroscopy Abnormalities?

OBJECTIVE

Early diagnosis of systemic sclerosis (SSc) is imperative, and Raynaud phenomenon (RP) is an important component of progressive vasculopathy. Nailfold videocapillaroscopy (NVC) is a well-established tool that can quantify structural vascular abnormalities. Digital thermal monitoring (DTM) assesses microvascular functional dysfunction related to thermoregulation. In this study, we investigated the correlation of NVC patterns and DTM variables in patients with SSc.

METHODS

Patients with SSc according to the 2013 American College of Rheumatology/European League Against Rheumatism criteria who consented and enrolled in the clinical care registry had NVC and DTM performed. For NVC, the number of capillaries (density), measurement of apical diameter (dimension), presence or absence of hemorrhages, and number of abnormal shapes were assessed to categorize 3 different qualitative patterns: early, active, and late. For DTM, Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery, and fingertip vascular function were assessed, and a vascular reactivity index (VRI) measurement was automated. Statistical evaluation was performed by nonparametric tests to assess the correlation of NVC and VRI.

RESULTS

Thirty-one SSc subjects with interpretable NVC and DTM performed on the same day were included in the study. VRI was progressively higher in SSc patients with early, active, and late NVC patterns of microangiopathy (P < 0.0001). There was a significant negative correlation between VRI and microhemorrhages scores (r = -0.363, P = 0.044).

CONCLUSION

Our study suggests that more advanced vasculopathy correlates to reduced microvascular function as detected by DTM and more advanced structural abnormalities detected by NVC. NVC and DTM may provide different aspects of vasculopathy quantification and complement each other as investigative tools.

Clinical significance of endothelial vasodilatory function evaluated by EndoPAT in patients with systemic sclerosis

Endothelial dysfunction is a hallmark of vasculopathy associated with systemic sclerosis (SSc). Reactive hyperemia peripheral arterial tonometry is a rapid and non-invasive technique to assess peripheral microvascular endothelial function by measuring changes in digital pulse volume during reactive hyperemia. Low scores of the reactive hyperemia index (RHI) imply an impaired vasodilatory response and, accordingly, impaired endothelial and vascular health. To investigate the clinical significance of the RHI in SSc patients, RHI values were measured in 43 SSc patients and 10 healthy controls. In diffuse cutaneous SSc (dcSSc) patients, RHI values were significantly decreased compared with healthy controls, and inversely correlated with disease duration. In total SSc patients, there was a significant inverse correlation between RHI values and skin score, and interstitial lung disease was associated with the decrease in RHI values. Among vascular symptoms, the current and past history of digital ulcers was seen more frequently in patients with decreased RHI values than in those with normal RHI values. Although no SSc patients had pulmonary arterial hypertension, an inverse correlation was evident between RHI values and mean pulmonary arterial pressure measured by right heart catheterization. These results indicate that the decrease in RHI values is associated with skin fibrosis, interstitial lung disease, digital ulcers and pulmonary vascular involvement leading to pulmonary arterial hypertension, supporting the canonical idea that endothelial dysfunction is a critical event underlying the development of tissue fibrosis and vascular complications in SSc.

Management of Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare and complex immune-mediated connective tissue disease characterized by multi-organ fibrosis and dysfunction. Systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is a leading cause of death in this population. Pulmonary arterial hypertension (PAH) can coexist with other forms of pulmonary hypertension in SSc, including pulmonary hypertension related to left heart disease, interstitial lung disease, chronic thromboembolism and pulmonary venous occlusive disease, which further complicates diagnosis and management. Available pulmonary arterial hypertension therapies target the nitric oxide, endothelin and prostacyclin pathways. These therapies have been studied in SSc-PAH in addition to idiopathic PAH, often with different treatment responses. In this article, we discuss the management as well as the treatment options for patients with SSc-PAH.

Arterial stiffness correlates with progressive nailfold capillary microscopic changes in systemic sclerosis: results from a cross-sectional study

BACKGROUND

While microangiopathy is well-documented in systemic sclerosis (SSc), a potential link between SSc and macrovascular disease is highly debated and remains to be established. The aim of the present study is to investigate the association between micro- and macrovascular involvement in the setting of SSc.

METHODS

Consecutive, consenting SSc patients were assessed by nailfold video-capillaroscopy (NVC) to evaluate the microcirculation. The number of capillaries per mm² and the capillaroscopic skin ulcer risk index (CSURI) were measured, and findings were also classified into three scleroderma patterns (i.e., early, active, and late). Carotid intima-media thickness (IMT), aortic augmentation index corrected for a heart rate of 75 beats per minute (AIx-75), carotid-femoral pulse wave velocity (PWV), and central systolic and diastolic blood pressure were also determined to assess macrovascular function.

RESULTS

A total of 37 patients were studied. A significant correlation was observed between AIx and the average number of capillaries per mm² (r = - 0.34, p = 0.047) and between AIx and CSURI (r = 0.35, p = 0.044). Patients with the "early" scleroderma pattern had lower AIx values compared with "active" (20.5 ± 11.4 vs 34.1 ± 11.5%, p = 0.02) and "late" (20.5 ± 11.4 vs 33.4 ± 8.8%, p = 0.05) patterns. No other significant correlations were found between macrovascular biomarkers (PWV, carotid IMT, systolic and diastolic central blood pressure) and the capillaroscopic measurements.

CONCLUSIONS

These data suggest that arterial stiffness (as assessed by AIx-75) correlates with microvascular damage in patients with SSc.

Mortality and hospitalization outcomes of interstitial lung disease and pulmonary hypertension in the Singapore systemic sclerosis cohort

OBJECTIVES

We compared mortality and hospitalization rates in four groups of patients with systemic sclerosis (SSc) [isolated pulmonary arterial hypertension (PAH) or interstitial lung disease (ILD), concomitant ILD-pulmonary hypertension (PH), and no/mild pulmonary involvement].

METHODS

In the Systemic Sclerosis Cohort Singapore (SCORE), ILD was diagnosed by HRCT and significant ILD was defined by forced vital capacity <70% predicted. Patients were classified as PAH if echocardiographic systolic pulmonary artery pressure (sPAP) ≥50 mmHg or right heart catheterization (RHC) mean PAP ≥25 mmHg. Multivariable regression analyses were performed to determine factors associated with mortality and hospital admissions per year. Cox proportional hazard model was used to analyze survival.

RESULTS

Of 490 SSc patients, 50 patients had PAH, 92 patients had ILD and 43 patients had ILD-PH. Of 93 patients with PAH or ILD-PH, 56 were based on echocardiography and 37 on RHC. Patients with ILD-PH (HR 3.77, 95% CI: 2.05-6.93) had the highest risk of death, followed by PAH (HR 3.03, 95% CI: 1.60-5.76) and ILD (HR 1.84, 95% CI: 1.04-3.28). After adjustment for confounders, PAH (HR 2.39, 95% CI: 1.13-5.07) remained independently associated with mortality, but not ILD-PH or ILD. Other factors associated with mortality were male gender, age at SSc diagnosis, malabsorption and digital ulcer/ gangrene. Increased hospitalization rate was associated with renal crisis, right heart failure and PAH medications, but not SSc groups.

CONCLUSION

PAH is an independent risk factor of mortality in SSc. Increased hospitalization rate was not associated with SSc groups. Other factors associated with increased mortality and hospital admissions were identified.

Non-invasive digital thermal monitoring and flow-mediated dilation in systemic sclerosis

OBJECTIVES

The fingers, toes, and tips of the nose and ears have specialised structural and functional features for thermoregulation, and are the most common areas of Raynaud's phenomenon in systemic sclerosis. Digital thermal monitoring (DTM) of vascular reactivity assesses Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery and fingertip vascular function. Flow mediated dilation (FMD) is an indirect measure of endothelial function, perfusion, and vasodilator ability. In this study, we investigated the cross-sectional correlation of FMD and DTM variables to inform an optimised noninvasive study of SSc endothelial function. A student's T-test was used to compare means of DTM across binary variables.

METHODS

Consented SSc registry patients were included in this analysis. The subjects were prepared for FMD and DTM per standardised guidelines. The SSc clinical features were recorded. Spearman's Rank Correlation was used to assess the strength of a relationship FMD and DTM variables.

RESULTS

Thirty-four SSc subjects had FMD and DTM performed on the same day. Relative (0.42, p=<0.02), absolute FMD (0.41, p<0.02), and shear rate (0.32, p<0.07) were weakly, but significantly correlated with the DTM. Reactive hyperemia (-0.44, p=0.000) was weakly inversely, but significantly related with DTM. Baseline diameter and flow were not significantly related to the DTM.

CONCLUSIONS

This non-invasive study of SSc endothelial function suggests that macrocirculation (including relative and absolute FMD, shear rate, and peak hyperemia) and microcirculatory thermoregulation (characterised by DTM) are significantly correlated, thus warrants further prospective study.

Attenuated nitric oxide bioavailability in systemic sclerosis: Evidence from the novel assessment of passive leg movement

NEW FINDINGS

What is the central question of this study? Do systemic sclerosis patients exhibit impaired nitric oxide-mediated vascular function of the lower limb and are these decrements correlated with plasma biomarkers for inflammation and oxidative stress? What is the main finding and its importance? Findings indicate impaired nitric oxide-mediated vascular function, linked to the incidence of digital ulcers and a milieu of inflammation and oxidative stress. However, the absence of significant correlations between individual biomarkers and blood flow responses suggests that the vasculopathy observed in systemic sclerosis may not be solely the result of derangements in the redox balance or inflammatory signalling.

ABSTRACT

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, which may be the consequence of inflammation and oxidative stress that ultimately leads to a reduced nitric oxide (NO) bioavailability. Passive leg movement (PLM) is a novel methodology for assessing lower limb vascular function that is predominantly NO dependent. We combined this vascular assessment with a comprehensive panel of plasma biomarkers to assess the axis of inflammation, oxidative stress and NO in SSc patients (n = 12; 62 ± 11 years of age) compared with healthy control subjects (n = 17; 60 ± 16 years of age). The PLM-induced changes in leg blood flow (LBF; 191 ± 104 versus 327 ± 217 ml min^-1 ) and LBF area under the curve (39 ± 104 versus 125 ± 131 ml) were reduced in SSc compared with control subjects. Stratification of patients according to history of digital ulcer (DU) formation revealed a further reduction in LBF area under the curve in DU (-13 ± 83 ml) versus non-DU (91 ± 102 ml) patients. Biomarkers of inflammation (C-reactive protein) and oxidative stress (malondialdehyde and protein carbonyl) were all elevated in SSc (C-reactive protein, 3299 ± 2372 versus 984 ± 565 ng ml^-1 ; malondialdehyde, 3.2 ± 1.1 versus 1.1 ± 0.7 μm; and protein carbonyl, 0.15 ± 0.05 versus 0.12 ± 0.03 nmol mg^-1 ), and C-reactive protein was further elevated in patients with a history of DU (4551 ± 2752 versus 2047 ± 1019 ng ml^-1 ) compared with non-DU, although these were not individually correlated with changes in LBF. These findings of impaired NO-mediated vascular function, linked to DU and a milieu of inflammation and oxidative stress, suggest that redox balance plays an important, but not necessarily deterministic, role in the vascular pathophysiology of SSc.

Implications of endothelial shear stress on systemic sclerosis vasculopathy and treatment

There are no Federal Drug Administration approved drugs for the treatment of systemic sclerosis vascular digital ulcers (DU) in the United States, which are thought to be an end-stage result of prolonged ischaemia due to severe, prolonged Raynaud's phenomenon. Most therapeutics for vasodilation used in SSc work different pathways to target the smooth muscle to induce vessel relaxation. Longitudinal studies of vascular function allow insight into the effects of medications used for Raynaud's phenomenon in the SSc patient population. In this review, we discuss vascular tone, the function of the endothelium in SSc, and provide the rationale for longitudinal studies of vascular function and therapeutics that target the endothelial shear stress in addition to vasodilation for treatment and prevention of DU. This review provides the rationale for vasodilatory medication use for treatment of SSc-related DU and justifies access to non-FDA approved medications for this indication.

Endothelial dysfunction in patients with granulomatosis with polyangiitis: a case-control study

Background

Granulomatosis with polyangiitis (GPA) is a rare granulomatous vasculitis affecting small- and medium-sized blood vessels. In optimally treated patients with long-standing disease, the common cause of death is atherosclerosis even in the absence of typical risk factors.

Objective

To evaluate endothelial dysfunction in GPA patients.

Methods

44 patients (21 men and 23 women) diagnosed with GPA and 53 controls matched for age, sex, BMI and typical risk factors for cardiovascular diseases (22 men and 31 women) were enrolled in the study. We measured each participant’s serum levels of vascular cell adhesion molecule-1 (VCAM-1), interleukin 6 (IL-6), and thrombomodulin. We also studied flow-mediated dilatation (FMD) of the brachial artery, intima-media thickness (IMT) of the common carotid artery and aortic stiffness using echocardiography.

Results

Patients with GPA showed a 15.9% increase in serum levels of VCAM-1 (p = 0.01), 66% of IL-6 (p < 0.001) and 50.9% of thrombomodulin (p < 0.001) compared to controls. FMD% was 48.9% lower in patients with GPA in comparison to controls (p < 0.001), after adjustment for potential confounders, with no differences regarding IMT or aortic stiffness. FMD% was negatively associated with duration of the disease (β = − 0.18 [95% CI: − 0.32 to − 0.04]), C-reactive protein (β = − 0.17 [95% CI: − 0.27 to − 0.07]), IL-6 (β = − 0.29 [95% CI: − 0.39 to − 0.19]), blood creatinine level (β = − 0.2 [95% CI: − 0.3 to − 0.1]), and IMT (β = − 0.14 (− 0.24 to − 0.04). In a multiple linear regression model, kidney function, IMT, pack-years of smoking, diabetes and level of VCAM-1 were independent predictors of lower FMD%.

Conclusion

GPA is characterized by endothelial dysfunction. FMD is a useful tool for the detection of endothelial injury.

Electronic supplementary material

The online version of this article (10.1007/s00296-018-4061-x) contains supplementary material, which is available to authorized users.

Exercise-based evaluations and interventions for pulmonary hypertension with connective tissue disorders

INTRODUCTION

Exercise intolerance is a common and often significant limitation in pulmonary arterial hypertension (PAH). This intolerance greatly affects the quality of life and function of the individual with PAH, irrespective of its etiology. In PAH associated with connective tissue disorders (PAH-CTD), exercise intolerance is further amplified by the presence of coexisting musculoskeletal manifestations of CTD. The evaluation of exercise capacity and prescription for exercise training therefore becomes a challenge to the clinician. Areas covered: This review highlights factors contributing to exercise intolerance in PAH-CTD, evaluation methods of exercise capacity and an overview on exercise training and a roadmap for future research. Expert commentary: Exercise intolerance is a complex interplay of cardiovascular, pulmonary, and musculoskeletal systems. Data from cardiopulmonary exercise tests have shown predictive abilities for both diagnosis and prognosis. In its absence, the 6-min walk test can be used to provide similar information thereby making the role of exercise testing an invaluable evaluation method in PAH-CTD. Exercise training data in PAH-CTD are still sparse, though, data from PAH studies suggest potential benefit. However, more research is required in this area of testing and training for greater understanding on exercise hemodynamic, phenotypes, and training benefits.

Endothelial cell-derived microvesicles: potential mediators and biomarkers of pathologic processes

This review focuses on the formation, composition and function of endothelial microvesicles (MV), often called microparticles (MP). MV release is a controlled event and is considered a hallmark of cellular activation or alteration. MV may affect the function of target cells through surface interaction and receptor activation, cellular fusion and the delivery of intravesicular cargo. Endothelial MV are released as a consequence of endothelial activation during inflammation and have been described to affect hemostasis, various aspects of inflammatory reaction, vessel formation, apoptosis and cell survival, endothelial cell differentiation and function. Recent data suggest the potential use of MV in diagnostics, assessment of severity and prediction of outcomes in inflammatory diseases and their utilization as targets, mediators and vectors in therapy.

Review of local wound management for scleroderma-associated digital ulcers

Digital ulcers (DU) are a common clinical problem in systemic sclerosis (SSc); however, there is no standardization of local wound care protocols for management of these lesions. There is a well-recognized need to develop and standardize non-pharmacological management of DU in patients with SSc, and to adopt these protocols in future clinical trials that focus on DU healing. The purpose of this review is to outline the types of DU that occur in SSc, and provide an update on the principles of wound management for these lesions based on the current literature and expert opinion.

Acute oral tetrahydrobiopterin administration ameliorates endothelial dysfunction in systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is a rare, autoimmune disease characterised by endothelial dysfunction, which is associated with peripheral vasculopathy, such as digital ulcers (DU). We sought to determine if acute oral administration of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase, would augment endothelial function in patients with SSc.

METHODS

Twelve SSc patients, of whom a majority had a history of DU, were studied 5 hours after oral BH4 administration (10 mg/kg body mass) or placebo on separate days using controlled, counterbalanced, double-blind, crossover experimental design.

RESULTS

There were no differences in blood markers of oxidative stress and brachial artery blood pressure, diameter, blood velocity, shear rate, or blood flow at rest between placebo and BH4 (p>0.05). Whereas, after a 5 minute suprasystolic forearm cuff occlusion, brachial artery peak reactive hyperemia (placebo: 313±30 vs. BH4: 347±37 ml/min, p<0.05) and flow-mediated dilation (FMD) (placebo: 3.0±0.8 vs. BH4: 4.8±0.8%, p<0.05) were significantly higher after acute BH4 administration, indicating an improvement in endothelial function. To determine if the vasodilatory effects of BH4 were specific to the vascular endothelium, brachial artery blood flow and vasodilation in response to sublingual nitroglycerin were assessed, and were found to be unaffected by BH4 (p>0.05).

CONCLUSIONS

These findings indicate that acute BH4 administration ameliorates endothelial dysfunction in patients with SSc. Given that endothelial dysfunction is known to be associated with DU in SSc patients, this study provides a proof-of-concept for the potential therapeutic benefits of BH4 in the prevention or treatment of DU in this population.

Exercise-induced brachial artery blood flow and vascular function is impaired in systemic sclerosis

Systemic sclerosis (SSc) is a rare autoimmune disease characterized by debilitating fibrosis and vascular dysfunction; however, little is known about the circulatory response to exercise in this population. Therefore, we examined the peripheral hemodynamic and vasodilatory responses to handgrip exercise in 10 patients with SSc (61 ± 4 yr) and 15 age-matched healthy controls (56 ± 5 yr). Brachial artery diameter, blood flow, and mean arterial pressure (MAP) were determined at rest and during progressive static-intermittent handgrip exercise. Patients with SSc and controls were similar in body stature, handgrip strength, and MAP; however, brachial artery blood flow at rest was nearly twofold lower in patients with SSc compared with controls (22 ± 4 vs. 42 ± 5 ml/min, respectively; P < 0.05). Additionally, SSc patients had an ∼18% smaller brachial artery lumen diameter with an ∼28% thicker arterial wall at rest (P < 0.05). Although, during handgrip exercise, there were no differences in MAP between the groups, exercise-induced hyperemia and therefore vascular conductance were ∼35% lower at all exercise workloads in patients with SSc (P < 0.05). Brachial artery vasodilation, as assessed by the relationship between Δbrachial artery diameter and Δshear rate, was significantly attenuated in the patients with SSc (P < 0.05). Finally, vascular dysfunction in the patients with SSc was accompanied by elevated blood markers of oxidative stress and attenuated endogenous antioxidant activity (P < 0.05). Together, these findings reveal attenuated exercise-induced brachial artery blood flow and conduit arterial vasodilatory dysfunction during handgrip exercise in SSc and suggest that elevated oxidative stress may play a role.

Comparison of clinical and serological parameters in female and male patients with systemic sclerosis

OBJECTIVES

The course of systemic sclerosis (SSc) can differ in female and male patients. According to the literature the incidence rates of diffuse cutaneous SSc, scleroderma renal crisis and digital ulceration are higher in male patients. The aim of the study was to compare selected clinical and serological parameters in male and female patients with SSc.

MATERIAL AND METHODS

The study encompassed 101 European Caucasian patients with SSc, including 23 men, hospitalized in the Department of Rheumatology. Patients fulfilled the American Rheumatism Association (ARA) classification criteria for SSc. The study groups of men and women were assessed according to the SSc subtype, incidence of internal organ involvement and presence of antinuclear antibodies considered SSc markers.

RESULTS

Diffuse cutaneous (dc) SSc was observed more commonly in men than in women (13/23 vs. 25/78; p = 0.03). The time from the development of Raynaud's phenomenon to the diagnosis was significantly shorter in male compared to female patients (3.2 ±4.7 vs. 7.5 ±7.1; p = 0.01). The incidence of scleroderma renal crisis (SRC) was significantly higher (3/23 vs. 2/78; p = 0.04) and of other calcifications significantly lower in the male group compared to the female group (1/23 vs. 20/78; p = 0.02).

CONCLUSIONS

We concluded that the incidence of dcSSc is higher in men compared to women. The time from the development of Raynaud's phenomenon to the diagnosis is shorter in the male compare to female group. The incidence of SRC is higher, whereas that of calcifications is lower in SSc men. The serological profiles of female and male patients with SSc are comparable.