Simona Sitia

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.

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.

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.

Coronary Flow Reserve and Asymmetric Dimethylarginine Levels: New Measurements for Identifying Subclinical Atherosclerosis in Patients with Psoriatic Arthritis

Objective. To identify the presence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA) and healthy controls using intima-media thickness (IMT), coronary flow reserve (CFR), and the plasma concentration of asymmetric dimethylarginine (ADMA), to evaluate the correlations among ADMA, IMT, and CFR. Methods. The study involved 22 patients who fulfilled the ClASsification of Psoriatic ARthritis study group criteria for PsA and a cohort of 35 healthy controls with no history or current signs of coronary artery disease (CAD). Common carotid IMT was measured using high-resolution B-mode ultrasonography. Dipyridamole transthoracic stress echocardiography was used to evaluate CFR. Blood samples were obtained to assess ADMA levels. The clinical manifestations were recorded. All patients were treated with disease-modifying antirheumatic drug, but none had received any biological or steroid therapy. Results. Plasma ADMA levels were significantly higher in the patients with PsA (0.71 ± 0.07 μmol/l vs 0.48 ± 0.07 μmol/l; p = 0.00) and CFR was significantly reduced in that group (2.86 ± 0.70 vs 3.3 ± 0.43; p < 0.01) compared to controls. Common carotid IMT was greater in the patients with PsA, but the difference was not significant (0.64 ± 0.26 mm vs 0.62 ± 0.5 mm; p = 0.65). There was a significant correlation between CFR and plasma ADMA levels in the PsA group (R = 0.28; p < 0.01), but no correlation between plasma ADMA levels and IMT (R = 0.02; p = 0.32), Disease Activity Score 28 (p = 0.52), or Psoriasis Area and Severity Index (p = 0.98). Conclusion. Our patients with PsA showed a profile of subclinical atherosclerosis. ADMA may be a useful marker of endothelial dysfunction in PsA.

Speckle tracking echocardiography: A new approach to myocardial function

Echocardiography is the most common diagnostic method for assessing cardiac function but some limitations affect this technique. Until now, visual assessment of wall motion and thickening has allowed only a subjective evaluation of myocardial function and requires long-term training. Recently, new echocardiographic techniques have been introduced to evaluate myocardial mechanics. Tissue Doppler imaging (TDI) technique is limited by angle-dependency such that only deformation along the ultrasound beam can be derived from velocities, while myocardium deforms simultaneously in three dimensions. Speckle tracking echocardiography (STE) is a more recent technique that provides a global approach to left ventricular myocardial mechanics, giving information about the three spatial dimensions of cardiac deformation. In this editorial, we describe the physical and pathophysiological concepts of STE, discussing the differences compared to TDI and underlining the pitfalls of this new technique.

Robotic treadmill training improves cardiovascular function in spinal cord injury patients.

BACKGROUND Body weight supported treadmill training (BWSTT) assisted with a robotic driven gait orthosis (DGO) is an emerging tool in rehabilitating patients with lost sensorimotor function. Few information about the effects of BWSTT on cardiovascular system are available. The purpose of this study was to determine the effects of BWSTT on: 1) left ventricular (LV) systo-diastolic function; 2) coronary flow reserve (CFR); 3) endothelial function in patients with lost sensorimotor function due to neurologic lesions. METHODS Fourteen adults (males 10, age 50.6±17.1years) with motor incomplete spinal cord injuries (SCI) due to trauma or spondylotic diseases underwent standard echocardiographic examination, non invasive assessment of CFR by dipyridamole stress echo and determination of plasma asymmetric dimethylarginine (ADMA) levels at baseline and after 6weeks of BWSTT. RESULTS At post training evaluation we observed lower LV end-diastolic (P=0.0164) and end-systolic volumes (P=0.0029) with increased ejection fraction (EF) (P=0.0266). We also observed a LV interventricular septum (IVS) (P=0.00469) increase. At the same time, we detected an improvement of LV diastolic function as witnessed by the reduction of isovolumic relaxation time (IVRT) (P=0.0404) and deceleration time (DT) (P=0.0405) with an increased E/A ratio (P=0.0040). Improved CFR (P=0.020) and reduced plasma ADMA levels (P=0.0005) have been observed too, in association with a reduction of the inflammatory status (C-reactive protein (CRP) (P=0.0022) and erythrocyte sedimentation rate (ESR) (P=0.0005)). CONCLUSION For the first time, this study demonstrated that 6weeks of BWSTT improved not only the sensorimotor function but also systo-diastolic LV function, CFR and endothelial dysfunction associated with a reduction of the inflammatory status in patients with incomplete SCI.

The heart in rheumatoid arthritis.

Morbidity and mortality rates are higher in rheumatoid arthritis (RA) patients than in the general population. Many studies have shown that coronary artery disease is one of the most common causes of death in RA and seems to occur at a younger age than in the general population. RA per se is as much a cardiovascular (CV) risk factor as diabetes, arterial hypertension and dyslipidemia etc., and so it is necessary to plan a follow-up using the same diagnostic and therapeutic approaches as those commonly used for primary and secondary prevention in non-RA patients at high CV risk. All of the cardiac structures can be affected during the course of RA (valves, the conduction system, the myocardium, endocardium and pericardium, and the coronary arteries), and cardiac complications include a variety of clinical manifestations. As these are all associated with an unfavourable prognosis, it is essential to detect subclinical cardiac involvement in still asymptomatic RA patients in order to assure adequate long-term treatment.

Cardiovascular involvement in psoriatic arthritis

Psoriasis is a chronic, genetically determined and immunomediated inflammatory skin disease that affects 2-3% of the Caucasian population. A considerable proportion of these patients develop a form of inflammatory arthritis known as psoriatic arthritis (PsA), although the prevalence of this has not been well defined. Patients with PsA have a higher mortality rate than the general population and the risk of mortality is related to disease severity at the time of presentation. Endothelial dysfunction and early atherosclerosis have been found in patients with PsA without any cardiovascular disease (CVD) risk factors, and experts believe that CVD is one of the leading causes of death, as it is in patients with rheumatoid arthritis (RA). Various disease-related mechanisms may be involved in the development of premature vascular damage in both cases, including an increased synthesis of proinflammatory mediators (such as cytokines, chemokines and adhesion molecules), autoantibodies against endothelial cell components, perturbations in T-cell subsets, genetic polymorphisms, hyperhomocysteinemia, oxidative stress, abnormal vascular repair, and iatrogenic factors. In a recent study of 22 patients with PsA without any signs of CVD, we found that the plasma concentration of asymmetric dimethylarginine (ADMA) levels were significantly high and coronary flow reserve (CFR) was significantly reduced. Moreover, there was a significant correlation between CFR and plasma ADMA levels in the PsA group. The significant correlation between the reduced CRF and increased ADMA levels suggests that, like patients with early RA, PsA patients suffer from endothelial dysfunction and impaired coronary microcirculation. Active PsA is a risk factor for CVD, and so PsA patients should be screened for subclinical forms of the disease and its risk factors, and an early treatment approach should be adopted.

Effects of treatment strategy on endothelial function

A large body of evidence indicates that endothelial dysfunction is a characteristic of patients with arterial hypertension. As functional abnormalities lead to impaired endothelium-dependent vasodilation, this early step of atherogenesis is potentially reversible. In addition to reducing blood pressure, the major families of anti-hypertensive drugs have a number of pleiotropic effects that could improve endothelial function. In particular, the renin-angiotensin system plays an important role in the pathogenesis of both arterial hypertension and endothelial dysfunction, and so drugs capable of limiting the dangerous effects of this hormonal axis, such as angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers and renin inhibitors, could help prevent/delay/reverse the atherosclerotic process. New third-generation β-blockers and 5-phosphodiesterase inhibitors may affect endothelial function. Furthermore, the HMGCoA-reductase inhibitors currently used to reduce cholesterol levels have major pleiotropic anti-inflammatory and anti-hypertensive effects. The preservation or recovery of endothelial function in hypertensive patients is crucial to inhibit the development of atherosclerosis and the onset of cardiovascular events. This review focuses on the ancillary effects of hypertensive drugs and HMGCoA-reductase inhibitors that go beyond lowering blood pressure and cholesterol levels.