Maurizio Turiel

From endothelial dysfunction to atherosclerosis.

It has recently emerged that endothelial dysfunction is an early step in the development of atherosclerosis and is mainly characterised by a reduction in the bioavailability of nitric oxide. All of the traditional cardiovascular (CV) risk factors (dyslipidemia, arterial hypertension, hyperglycemia and diabetes) are associated with endothelial dysfunction, and oxidised low-density lipoproteins, the renin-angiotensin axis and insulin resistance play important roles in the pathogenesis of impaired endothelial function. The increased expression of adhesion molecules and pro-inflammatory cytokines leads to abnormal endothelium-dependent vasodilation which could be investigated using vasoreactivity tests such as flow-mediated dilation in the brachial artery. Recently, new evidences showed that the immune system plays an important role in the pathogenesis of endothelial dysfunction and atherosclerosis with a particular regard towards autoimmunity. The high prevalence of the atherosclerotic process in systemic autoimmune diseases supports the hypothesis of the immune pathogenesis. Evaluating coronary microvascular dysfunction by means of transthoracic echocardiography with non-invasive coronary flow reserve assessment is particularly interesting as it could detect preclinical impairment of coronary microvascular function. The discovery that the mechanisms responsible for endothelial damage have a genetic basis could improve the approach to CV diseases. This review summarises the most important aspects of the pathogenesis and development of endothelial dysfunction, with particular attention to the role of traditional CV risk factors, the usefulness of vasoreactivity tests, and the future perspectives opened by genetic studies.

Autoimmunity and Anti‐TNF‐α Agents

Abstract: Treatment of rheumatoid arthritis (RA) patients with anti‐tumor necrosis factor‐alpha (anti‐TNF‐α) biologic agents has been associated with a reduction in the levels of specific autoantibodies, such as rheumatoid factor (RF) and anticyclic citrullinated peptide (anti‐CCP), and the induction of non‐ organ‐specific autoantibodies (antinuclear antibodies [ANAs], anti‐dsDNA, and antiphospholipid antibodies [aPLs]). The mechanisms by which the blockade of anti‐TNF‐α decreases the generation of specific autoantibodies, such as anti‐CCP and RF, are not yet known. However, it has been shown that these agents can downregulate the production of several inflammatory cytokines and mediators and that these anti‐inflammatory effects may account for reduced autoantibody generation, particularly in the synovial compartment. Infliximab treatment leads to the induction of ANAs in 63.8% of RA patients and 49.1% of Crohns disease (CD) patients, and anti‐dsDNA antibodies in 13% of RA patients and 21.5% of CD patients, respectively. The development of ANAs and anti‐dsDNA antibodies has also been described after etanercept therapy in 11% and 15% of RA patients, respectively. In the controlled trials, increases in ANA and anti‐dsDNA titers were observed in 5.3% and in 12.9% of adalimumab‐treated RA patients. Only limited data on the induction of aPL antibodies during TNF‐α blocking treatment are available.

Cardiovascular involvement in systemic autoimmune diseases

Autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), primary antiphospholipid syndrome (APS), systemic sclerosis and systemic vasculitis, affect a large number of people in whom one of the leading causes of morbidity and mortality is cardiovascular disease. Cardiovascular disease is associated with the development of accelerated atherosclerosis. It seems to occur at a younger age than in the general population, is often asymptomatic and, in addition to traditional risk factors, also involves specific risk factors as chronic inflammation, the duration and activity of the autoimmune disease, and immunosuppressive therapy. The early phases of cardiovascular involvement in patients with autoimmune diseases may be clinically silent, with only a microcirculation disorder present. There are various means of detecting morphological cardiac damage: coronary angiography remains the gold standard for diagnosing coronary stenosis, but new, non invasive and more reliable methods have been introduced into clinical practice in order to detect subclinical microcirculation abnormalities.

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.

Non-stationarities significantly distort short-term spectral, symbolic and entropy heart rate variability indices

The autonomic regulation is non-invasively estimated from heart rate variability (HRV). Many methods utilized to assess autonomic regulation require stationarity of HRV recordings. However, non-stationarities are frequently present even during well-controlled experiments, thus potentially biasing HRV indices. The aim of our study is to quantify the potential bias of spectral, symbolic and entropy HRV indices due to non-stationarities. We analyzed HRV series recorded in healthy subjects during uncontrolled daily life activities typical of 24 h Holter recordings and during predetermined levels of robotic-assisted treadmill-based physical exercise. A stationarity test checking the stability of the mean and variance over short HRV series (about 300 cardiac beats) was utilized to distinguish stationary periods from non-stationary ones. Spectral, symbolic and entropy indices evaluated solely over stationary periods were contrasted with those derived from all the HRV segments. When indices were calculated solely over stationary series, we found that (i) during both uncontrolled daily life activities and controlled physical exercise, the entropy-based complexity indices were significantly larger; (ii) during uncontrolled daily life activities, the spectral and symbolic indices linked to sympathetic modulation were significantly smaller and those associated with vagal modulation were significantly larger; (iii) while during uncontrolled daily life activities, the variance of spectral, symbolic and entropy rate indices was significantly larger, during controlled physical exercise, it was smaller. The study suggests that non-stationarities increase the likelihood to overestimate the contribution of sympathetic control and affect the power of statistical tests utilized to discriminate conditions and/or groups.

Warped-average template technique to track on a cycle-by-cycle basis the cardiac filling phases on left ventricular volume

The dynamic time warping approach is utilised to obtain a template from the left ventricular volume signal. The technique, by performing shrinking and enlarging of the temporal axes of two waveforms, indicates the best non-linear alignment between them. In this application this technique is used to track on a cycle-by-cycle basis the diastasis onset and offset thus allowing one to reliably measure temporal sub-intervals of the filling period.

Effects of long-term disease-modifying antirheumatic drugs on endothelial function in patients with early rheumatoid arthritis.

Rheumatoid arthritis (RA) is associated with enhanced atherosclerosis and impaired endothelial function early after the onset of the disease and cardiovascular (CV) disease represents one of the leading causes of morbidity and mortality. It is well known that disease modifying antirheumatic drugs (DMARDs) are able to improve the course of the disease and the quality of life of these patients, but little is known about the effects of DMARDs on CV risk and endothelial dysfunction. Our goal was to examine the effects of long-term therapy with DMARDs on endothelial function and disease activity in early RA (ERA). Twenty-five ERA patients (mean age 52 ± 14.6 years, disease duration 6.24 ± 4.10 months) without evidence of CV involvement were evaluated for disease activity score (DAS-28), 2D-echo derived coronary flow reserve (CFR), common carotid intima-media thickness (IMT) and plasma asymmetric dimethylarginine (ADMA) levels at baseline and after 18 months of treatment with DMARDs (10 patients with methotrexate and 10 with adalimumab). DMARDs significantly reduced DAS-28 (6.0 ± 0.8 vs. 2.0 ± 0.7; P < 0.0001) and improved CFR (2.4 ± 0.2 vs. 2.7 ± 0.5; P < 0.01). Common carotid IMT and plasma ADMA levels did not show significant changes. The present study shows that DMARDs, beyond the well known antiphlogistic effects, are able to improve coronary microcirculation without a direct effect on IMT and ADMA, clinical markers of atherosclerosis. Treatment strategies in ERA patients with high inflammatory activity must be monitored to identify beneficial effects on preclinical markers of vascular function.

Cardiac involvement in systemic rheumatic diseases: An update

The high rates of cardiovascular (CV) mortality and morbidity observed in patients with systemic autoimmune diseases (SADs) cannot be fully explained by traditional atherosclerosis risk factors as standard therapy (i.e. corticosteroids and methotrexate), cytokines and disease activity may all contribute to accelerated atherosclerosis. There is considerable evidence showing that chronic inflammation and immune dysregulation play a pathogenetic role in the development of atherosclerosis in patients with SADs. Chronic inflammation, accelerated atherosclerosis and functional abnormalities of the endothelium suggest that subclinical CV involvement begins soon after the onset of the disease and progresses with disease duration. All cardiac structures may be affected during the course of SADs (valves, the conduction system, the myocardium, endocardium and pericardium, and coronary arteries), and the cardiac complications have a variety of clinical manifestations. As these are all associated with an unfavourable prognosis, it is essential to detect subclinical cardiac involvement in asymptomatic SAD patients, and begin adequate management and treatment early.

Thrombotic risk factors in primary antiphospholipid syndrome : A 5-year prospective study

Background and Purpose— Because thromboembolic events are frequently observed in primary antiphospholipid syndrome (PAPS), we assessed the risk factors for new thrombotic episodes. Methods— Fifty-six PAPS patients (mean age, 37±10 years) were prospectively studied for 5 years. The preliminary Sapporo classification criteria for antiphospholipid syndrome (APS; a medium–high anticardiolipin antibody [aCL] titer and/or a positive lupus anticoagulant [LA] test in the presence of vascular thrombosis and/or pregnancy morbidity) were used to confirm the diagnosis. Thrombotic episodes or pregnancy losses before a diagnosis of PAPS were considered events, and any new disease manifestation other than thrombocytopenia was considered a recurrent event. Only patients with objectively verified thrombotic events were included in the study. Results— Twenty-one new thrombotic events were observed in 15 subjects (26.8%), including 3 (5.4%) who died during the follow-up. The patients with IgG aCL levels of >40 IgG phospholipid unit (GPL-U) showed a higher incidence of new thrombotic events (43.3%) than those with levels of ≤40 GPL-U (7.7%). Univariate analysis identified a history of recurrent clinical events (P=0.004), a highly positive aCL titer (P=0.007), and the presence of cardiac abnormalities (P=0.036) as significant risk factors for new thrombotic events. A multivariate regression model confirmed that an IgG aCL titer of >40 GPL-U was an independent risk factor for thrombosis (odds ratio, 9.17; 95% confidence interval, 1.83 to 46.05). Conclusions— A high IgG aCL titer is the strongest predictor of new thrombotic events in PAPS patients.

Is atherosclerosis an autoimmune disease

Immunologic research into pathogenic mechanisms operating in autoimmune-mediated atherosclerosis initially focused on adaptive immunity. Current interest is directed to more basic inflammatory mechanisms. Chronic inflammation (innate immunity-associated) may trigger initial events that can lead to atherosclerotic cardiovascular disease. This chronic inflammation may start early in life and be perpetuated by classic atherosclerosis risk factors. Lipid peroxidation of low-density lipoprotein seems to be a key event in the initiation and progression of atherosclerosis. Oxidized low-density lipoprotein triggers inflammatory and immunogenic events that promote endothelial dysfunction and the synthesis and secretion of pro-inflammatory cytokines, leading to an autoimmune response capable of accelerating the intracellular accumulation of lipids within atherosclerotic plaques. Oxidized low-density lipoprotein binds β2-glycoprotein I to form circulating complexes found in both autoimmune and non-autoimmune atherosclerosis. It is likely that β2-glycoprotein I and/or these complexes contribute to early atherogenesis by stimulating pro-inflammatory innate immunity through endogenous sensors and inflammasome/interleukin-1 pathways. We discuss the chronic inflammatory (innate) and autoimmune (adaptive) responses operating in atherosclerosis to discern the role of autoimmunity in atherosclerotic cardiovascular disease.