Microvascular function is preserved in newly diagnosed rheumatoid arthritis and low systemic inflammatory activity

Endothelial Dysfunction in Patients with Rheumatoid Arthritis: the Role of Hypertension

PURPOSE OF REVIEW

To review the data on the role of endothelial dysfunction and the impact of hypertension as a potent mediator of cardiovascular disease in patients with rheumatoid arthritis (RA).

RECENT FINDINGS

RA represents the most common autoimmune rheumatic disorder and is characterized by chronic systemic inflammation predisposing to cardiovascular complications. Cardiovascular mortality is increased among patients with RA and represents the leading cause of death. Although the exact prevalence is debated, hypertension is increased in RA. Hypertension acts synergistically with chronic inflammation and accounts, at least partially, for the increased cardiovascular morbidity in this group of patients. Endothelial dysfunction is considered a primary process in the pathogenesis of hypertension and cardiovascular diseases and contributes significantly to the development and progression of the associated micro- and macrovascular complications. Even though several studies in patients with RA have shown the presence of endothelial dysfunction with traditional methods, novel biochemical and vascular methods for the evaluation of endothelial dysfunction have been scarcely applied. In addition, it remains unclear whether and to which extent endothelial dysfunction in RA is present regardless of concomitant hypertension, even in well-controlled patients. Hypertension, endothelial dysfunction, and chronic systemic inflammation appear as a mutually reinforcing triad aggravating cardiovascular risk in patients with RA. Detection of endothelial dysfunction in patients with RA in the early stages further aiming at the development of novel therapeutic targets might contribute to prevention of cardiovascular complications and remains under investigation.

A prospective, longitudinal monocentric study on laser Doppler imaging of microcirculation: comparison with macrovascular pathophysiology and effect of adalimumab treatment in early rheumatoid arthritis

Increased cardiovascular (CV) morbidity and mortality have been found in rheumatoid arthritis (RA). Tumour necrosis factor α (TNF-α) inhibitors may improve vascular function. In the first part of this study, we determined microcirculation during postoocclusive reactive hyperemia (PORH) representing endothelial function. In a nonselected population (n = 46) we measured flow-mediated vasodilation (FMD) of the brachial artery and laser Doppler flow (LDF) by ultrasound. Among LDF parameters, we determined TH1 (time to half before hyperemia), TH2 (time to half after hyperemia), Tmax (time to maximum) and total hyperemic area (AH). We measured von Willebrand antigen (vWF:Ag) by ELISA. In the second part of the study, we assessed the effects of adalimumab treatment on microcirculatory parameters in 8 early RA patients at 0, 2, 4, 8 and 12 weeks. We found significant positive correlations between FMD and LDF Tmax (R = 0.456, p = 0.002), FMD and TH2 (R = 0.435, p = 0.004), and negative correlation between vWF:Ag and Tmax (R = - 0.4, p = 0.009) and between vWF:Ag and TH2 (R = - 0.446, p = 0.003). Upon adalimumab therapy in early RA, TH2 times improved in comparison to baseline (TH2_baseline = 26.9 s vs. TH2_4weeks = 34.7 s, p = 0,032), and this effect prolonged until the end of treatment (TH2_8weeks = 40.5, p = 0.026; TH2_12weeks = 32.1, p = 0.013). After 8 weeks of treatment, significant improvement was found in AHa (AH_baseline = 1599 Perfusion Units [PU] vs. AH_8weeks = 2724 PU, p = 0.045). The PORH test carried out with LDF is a sensitive option to measure endothelial dysfunction. TH1 and TH2 may be acceptable and reproducible markers. In our pilot study, treatment with adalimumab exerted favorable effects on disease activity, endothelial dysfunction and microcirculation in early RA patients.

Effects of 1-year anti-TNF-α therapy on vascular function in rheumatoid arthritis and ankylosing spondylitis

Accelerated atherosclerosis, increased cardiovascular morbidity and mortality have been associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Vascular function, clinical and laboratory markers and the effects of anti-TNF therapy were assessed in arthritides. Fifty-three 53 patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol and 17 AS patients treated with ETN were included in a 12-month follow-up study. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT) and arterial pulse-wave velocity (PWV) in all patients. All assessments were performed at baseline and 6 and 12 months after treatment initiation. A significant improvement of brachial artery FMD was observed after 6 months (p = 0.004). A tendency of FMD improvement was also observed after 12 months (p = 0.065). ccIMT did not change throughout the year. PWV significantly improved after 12 months (p = 0.034). Higher baseline ccIMT (p = 0.009) and PWV (p = 0.038) were associated with clinical non-response (cNR) versus response (cR) to biologics. Multiple analysis confirmed the association of baseline ccIMT with age (p = 0.003) and cNR (p = 0.009), as well as that of baseline PWV with age at diagnosis (p = 0.022) and current chest pain (p = 0.004). Treatment itself determined the 12-month changes in FMD (p = 0.020) and PWV (p = 0.007). In a mixed cohort of RA and AS patients, TNF inhibition improved or stabilized vascular pathophysiology. Inflammation may be associated with FMD, while, among others, cNR may influence vascular function.

Microvascular endothelial dysfunction in rheumatoid arthritis

The systemic autoimmune disease rheumatoid arthritis (RA) is characterized by increased cardiovascular mortality and morbidity and is an independent cardiovascular risk factor. Cardiovascular diseases (CVDs) result from accelerated atherogenesis, which is a consequence of endothelial dysfunction in the early stages of the disease. Endothelial dysfunction is a functional and reversible alteration of endothelial cells and leads to a shift in the properties of the endothelium towards reduced vasodilation, a pro-inflammatory state, and proliferative and prothrombotic properties. In RA, endothelial dysfunction can occur in the large vessels (such as the conduit arteries) and in the small vessels of the microvasculature, which supply oxygen and nutrients to the tissue and control inflammation, repair and fluid exchange with the surrounding tissues. Growing evidence suggests that microvascular endothelial dysfunction contributes to CVD development, as it precedes and predicts the development of conduit artery atherosclerosis and associated risk factors. As such, numerous studies have investigated microvascular endothelial dysfunction in RA, including its link with disease activity, disease duration and inflammation, the effect of treatments on endothelial function, and possible circulating biomarkers of microvascular endothelial dysfunction. Such findings could have important implications in the cardiovascular risk management of patients with RA.

Dermal capillary rarefaction as a marker of microvascular damage in patients with rheumatoid arthritis: Association with inflammation and disorders of the macrocirculation

OBJECTIVE

Capillary rarefaction is observed in various cardiovascular diseases, yet it remains understudied in RA, a chronic inflammatory disease accompanied by excess cardiovascular risk. We quantified capillary density in RA patients and explored potential associations with macrocirculatory disorders, inflammation, and cardiovascular risk.

METHODS

Dermal capillary density was assessed with nailfold capillaroscopy in RA and non-RA individuals, using specifically designed semiautomated software. Macrocirculation assessments included large artery stiffening, evaluated with PWV, and myocardial blood flow, calculated as cardiac index from impedance cardiography. Cardiovascular risk score was estimated from the Framingham Heart Study.

RESULTS

The number of capillaries per visual field was lower in patients (n = 99) compared to controls (n = 35) (132.6 ± 30.3 vs 152.9 ± 25.2, P = .001). In the RA group, capillary density negatively correlated with CRP and PWV, and positively with HDL and cardiac index. In the multivariate analysis, CRP independently predicted capillary rarefaction (P = .044). Capillary density significantly correlated with cardiovascular risk, even after adjustment for inflammation (P = .030).

CONCLUSION

Capillary rarefaction appears pronounced in RA and correlates with lower cardiac output, increased arterial stiffness, and cardiovascular risk. However, the associations with macrocirculatory disorders may be obscured by inflammation, which appears as the major contributor to capillary rarefaction in RA.

Relationships Between Type 2 Diabetes, Neuropathy, and Microvascular Dysfunction: Evidence From Patients With Cryptogenic Axonal Polyneuropathy

OBJECTIVE

This study investigated whether the relationship between neuropathy and microvascular dysfunction in patients with type 2 diabetes is independent of diabetes-related factors. For this purpose, we compared skin microvascular function in patients with type 2 diabetes with that of patients with cryptogenic axonal polyneuropathy (CAP), a polyneuropathy of unknown etiology.

RESEARCH DESIGN AND METHODS

Cross-sectional information was collected from 16 healthy controls (HCs), 16 patients with CAP, 15 patients with type 2 diabetes with polyneuropathy (DPN), and 11 patients with type 2 diabetes without polyneuropathy. Axonal degeneration was assessed with skin biopsy and nerve conduction studies. Microvascular skin vasodilation was measured using laser Doppler fluxmetry combined with iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP).

RESULTS

Patients with CAP and DPN demonstrated a similar decrease in intraepidermal nerve fiber density and sural sensory nerve action potential compared with HCs. The vasodilator response to ACh was similar among patients with CAP (relative mean difference based on log values 13.3%; 95% CI -35.0 to 97.7%; P = 0.652) but was lower in the patients with diabetes with neuropathy (157.5%; 42.0-366.7%; P = 0.003) and without neuropathy (174.2%; 44.2-421.3%; P = 0.003) compared with HCs. No significant differences were found between the groups of patients with diabetes (P = 0.845). The vasodilator response to SNP was not significantly different among the groups (P = 0.082).

CONCLUSIONS

In this study, endothelium-dependent vasodilation was reduced in patients with type 2 diabetes regardless of the presence of polyneuropathy, whereas microvascular vasodilation was normal in patients with CAP. These data suggest that in type 2 diabetes, neuropathy does not contribute to impaired microvascular endothelium-dependent vasodilation and vice versa. In addition, this study suggests that impaired microvascular vasodilation does not contribute to CAP.

Contractile, but not endothelial, dysfunction in early inflammatory arthritis: a possible role for matrix metalloproteinase-9

BACKGROUND AND PURPOSE

Excess morbidity/mortality in rheumatoid arthritis (RA) is associated with increased incidence of cardiovascular disease. In this 'proof-of-concept' study, vascular function was characterized in the murine collagen-induced arthritis (mCIA) model, the benchmark choice for evaluation of the pathological processes and assessment of new therapies.

EXPERIMENTAL APPROACH

Mice in the very early stages of arthritis development [and appropriate naïve (non-immunized) age-matched controls] were used in the study. Blood pressure was measured using tail cuff plethysmography. Vascular function in rings of isolated aorta was studied with isometric tension myography. Levels of NO metabolites (NO(x)), MMP-9 protein and IL-1β in plasma and MMP-9 protein in aortic homogenates were quantified.

KEY RESULTS

Impaired vascular contractile responses in arthritis were unaffected by ex vivo inhibition of NOS (endothelial/neuronal and inducible) or COX activities. Endothelium-dependent and -independent relaxation, plasma NO(x) and blood pressure were unaffected by arthritis. Plasma and aortic homogenate MMP-9 protein levels were increased significantly in arthritis. Incubation of aortic tissues from naïve control animals with exogenous MMP-9 impaired subsequent contractile responses, mirroring that observed in arthritis. A role for IL-1β in perpetuating contractile dysfunction and increasing aortic MMP-9 was excluded.

CONCLUSIONS AND IMPLICATIONS

These data identify for the first time a relationship between early arthritis and contractile dysfunction and a possible role for MMP-9 therein, in the absence of overt endothelial dysfunction or increased NO production. As such, MMP-9 may constitute a significant target for early intervention in RA patients with a view to decreasing risk of cardiovascular disease.

Microcirculation as determined by iontophoresis in SLE-patients and controls

Background: The risk of cardiovascular disease (CVD), microangiopathy and prevalence of atherosclerotic plaques are increased in Systemic Lupus Erythematosus (SLE). As systemic endothelial dysfunction is one of the earliest signs of these vascular outcomes in the general population we assessed skin microvascular endothelial function in SLE patients. Methods: Endothelial function in skin was tested with local application of acetylcholine (inducing endothelium-dependent vasodilatation) and any concomitant increase in skin perfusion was measured with Laser Doppler Fluxmetry (LDF) in 84 SLE-patients (83% women, mean age 47 years) and 81 age and sex matched controls. Common carotid intima-media thickness (cIMT) and plaque occurrence were also determined using B-mode ultrasound. Results: There were no significant differences in skin microvascular endothelial function between SLE-patients and controls. In the SLE group, endothelial function did not vary in relation to skin manifestations, Raynaud's phenomenon, nephritis or plaque occurrence. In SLE patients with CVD, however, endothelial function was impaired. Conclusion: Skin microvascular endothelial function is associated with CVD but not with early signs of atherosclerosis in SLE-patients. The endothelial function is not different in SLE-patients as compared to controls.

Risk of atrial fibrillation and stroke in rheumatoid arthritis: Danish nationwide cohort study

OBJECTIVES

To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke.

DESIGN

Longitudinal nationwide register based cohort study.

SETTING

Inpatient and outpatient hospital care in Denmark from 1997 to 2009.

PARTICIPANTS

Entire Danish population aged over 15 years without rheumatoid arthritis, atrial fibrillation, or stroke before 1997. Participants with rheumatoid arthritis were identified by individual level linkage of diagnoses and rheumatoid arthritis treatment.

MAIN OUTCOME MEASURES

Rates of atrial fibrillation and stroke.

RESULTS

Of 4,182,335 participants included in the cohort, 18,247 were identified as having rheumatoid arthritis during follow-up, with a mean age at disease onset of 59.2 years and a median follow-up of 4.8 years. A total of 156,484 people, including 774 with rheumatoid arthritis, were diagnosed as having atrial fibrillation (age and sex matched event rates of 8.2 per 1000 person years in rheumatoid arthritis patients and 6.0 per 1000 person years in the general population), with an adjusted incidence rate ratio of 1.41 (95% confidence interval 1.31 to 1.51). In addition, 165,343 people, including 718 with rheumatoid arthritis, had a stroke (7.6 per 1000 person years in rheumatoid arthritis and 5.7 per 1000 person years in the general population), with a resultant rate ratio of 1.32 (1.22 to 1.42). For both atrial fibrillation and stroke, relative risks were increased in all strata based on thirds of sex and age, with higher relative risks in younger patients but higher absolute risk differences in older patients.

CONCLUSIONS

Rheumatoid arthritis was associated with an increased incidence of atrial fibrillation and stroke. The novel finding of increased risk of atrial fibrillation in rheumatoid arthritis suggests that this arrhythmia is relevant in cardiovascular risk assessment of these patients.

Validated methods for assessment of subclinical atherosclerosis in rheumatology

Rheumatoid arthritis, as well as other types of arthritides and connective tissue diseases, is associated with accelerated atherosclerosis, and increased cardiovascular morbidity and mortality. The early signs of cardiovascular disease therefore need to be recognized in patients with these conditions so that effective cardiovascular protection can be introduced. This Review provides an overview of validated techniques that are currently available to determine subclinical atherosclerosis in patients with rheumatic conditions. Techniques for early assessment of endothelial dysfunction include brachial artery flow-mediated vasodilation and laser Doppler flowmetry. Coronary circulation can be assessed by measuring coronary flow reserve using CT, MRI or PET based techniques. The standard indicators of arterial stiffness are pulse-wave velocity and the augmentation index. Carotid atherosclerosis is determined by the common carotid intima-media thickness (ccIMT) measurement or by the assessment of plaques and plaque areas. The combination of ccIMT with plaque assessment is likely to increase the predictive value of this approach. The potential use of a multimarker approach to increase the diagnostic and prognostic value of these clinical assessments is also discussed.