Domenico Corradi

Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart.

A growing amount of evidence suggests that regional fat distribution plays an important part in the development of an unfavorable metabolic and cardiovascular risk profile. Epicardial fat is a metabolically active organ that generates various bioactive molecules, which might significantly affect cardiac function. This small, visceral fat depot is now recognized as a rich source of free fatty acids and a number of bioactive molecules, such as adiponectin, resistin and inflammatory cytokines, which could affect the coronary artery response. The observed increases in concentrations of inflammatory factors in patients who have undergone coronary artery bypass grafting remain to be confirmed in healthy individuals. Furthermore, epicardial adipose mass might reflect intra-abdominal visceral fat. Therefore, we propose that echocardiographic assessment of this tissue could serve as a reliable marker of visceral adiposity. Epicardial adipose tissue is also clinically related to left ventricular mass and other features of the metabolic syndrome, such as concentrations of LDL cholesterol, fasting insulin and adiponectin, and arterial blood pressure. Echocardiographic assessment of epicardial fat could be a simple and practical tool for cardiovascular risk stratification in clinical practice and research. In this paper, we briefly review the rapidly emerging evidence pointing to a specific role of epicardial adipose tissue both as a cardiac risk marker and as a potentially active player in the development of cardiac pathology.

PTX3, A Prototypical Long Pentraxin, Is an Early Indicator of Acute Myocardial Infarction in Humans

BACKGROUND Inflammation is an important component of ischemic heart disease. PTX3 is a long pentraxin whose expression is induced by cytokines in endothelial cells, mononuclear phagocytes, and myocardium. The possibility that PTX3 is altered in patients with acute myocardial infarction (AMI) has not yet been tested. METHODS AND RESULTS Blood samples were collected from 37 patients admitted to the coronary care unit (CCU) with symptoms of AMI. PTX3 plasma concentrations, as measured by ELISA, higher than the mean+2 SD of age-matched controls (2.01 ng/mL) were found in 27 patients within the first 24 hours of CCU admission. PTX3 peaked at 7.5 hours after CCU admission, and mean peak concentration was 6.94+/-11.26 ng/mL. Plasma concentrations of PTX3 returned to normal in all but 3 patients at hospital discharge and were unrelated to AMI site or extent, Killip class at entry, hours from symptom onset, and thrombolysis. C-reactive protein peaked in plasma at 24 hours after CCU admission, much later than PTX3 (P<0.001). Patients >64 years old and women had significantly higher PTX3 concentrations at 24 hours (P<0.05). PTX3 was detected by immunohistochemistry in normal but not in necrotic myocytes. CONCLUSIONS PTX3 is present in the intact myocardium, increases in the blood of patients with AMI, and disappears from damaged myocytes. We suggest that PTX3 is an early indicator of myocyte irreversible injury in ischemic cardiomyopathy.

Dilated and Failing Cardiomyopathy in Bradykinin B2 Receptor Knockout Mice

BACKGROUND The activation of B(2) receptors by kinins could exert cardioprotective effects in myocardial ischemia and heart failure. METHODS AND RESULTS To test whether the absence of bradykinin B(2) receptors may affect cardiac structure and function, we examined the developmental changes in blood pressure (BP), heart rate, and heart morphology of bradykinin B(2) receptor gene knockout (B(2)(-/-)), heterozygous (B(2)(+/-)), and wild-type (B(2)(+/+)) mice. The BP of B(2)(-/-) mice, which was still normal at 50 days of age, gradually increased, reaching a plateau at 6 months (136+/-3 versus 109+/-1 mm Hg in B(2)(+/+), P<0.01). In B(2)(+/-) mice, BP elevation was delayed. At 40 days, the heart rate was higher (P<0.01) in B(2)(-/-) and B(2)(+/-) than in B(2)(+/+) mice, whereas the left ventricular (LV) weight and chamber volume were similar among groups. Thereafter, the LV growth rate of B(2)(-/-) and B(2)(+/-) mice was accelerated, leading at 360 days to a LV weight-to-body weight ratio that was 9% and 17% higher, respectively, than that of B(2)(+/+) mice. In B(2)(-/-) mice, hypertrophy was associated with a marked chamber dilatation (42% larger than that of B(2)(+/+) mice), an elevation in LV end-diastolic pressure (25+/-3 versus 5+/-1 mm Hg in B(2)(+/+) mice, P<0.01), and reparative fibrosis. CONCLUSIONS The disruption of the bradykinin B(2) receptor leads to hypertension, LV remodeling, and functional impairment, implying that kinins are essential for the functional and structural preservation of the heart.

Evidence of autoimmunity in chronic periaortitis: a prospective study.

BACKGROUND Chronic periaortitis includes idiopathic retroperitoneal fibrosis, inflammatory aneurysms of the abdominal aorta, and perianeurysmal retroperitoneal fibrosis. It is considered to be due to advanced atherosclerosis, but is often associated with systemic autoimmune disorders. METHODS We studied 16 consecutive patients who were diagnosed with chronic periaortitis by computed tomography. Each patient underwent a physical examination, routine laboratory tests, measurement of autoantibodies, thyroid echotomography, and chest radiography. Aortic wall or periaortic retroperitoneal samples from 9 patients who underwent surgery were available for histologic examination and immunohistochemical characterization of the inflammatory infiltrate. RESULTS Twelve patients had constitutional symptoms, 14 had an elevated erythrocyte sedimentation rate, and 13 had an elevated C-reactive protein level. Antinuclear antibodies were positive in 10 patients. Three patients had autoimmune thyroiditis, and 1 had seropositive rheumatoid arthritis. Antineutrophil cytoplasmic antibodies were positive in 3 patients who presented with rapidly progressive renal failure. Pathologic examination of the aortic and periaortic specimens revealed moderate to severe inflammatory infiltration, mainly consisting of B cells and CD4(+) T cells. Vasculitis with fibrinoid necrosis involving the aortic vasa vasorum and the small and medium retroperitoneal vessels was found in seven of the nine histologic samples. CONCLUSION These clinical and pathologic features support the hypothesis that, at least in some patients, chronic periaortitis is a systemic autoimmune disease, perhaps involving a vasculitic process of small and medium vessels.

The Role of Oxidative Stress in the Pathogenesis of Type 2 Diabetes Mellitus Micro- and Macrovascular Complications: Avenues for a Mechanistic-Based Therapeutic Approach

A growing body of evidence suggests that oxidative stress plays a key role in the pathogenesis of micro- and macrovascular diabetic complications. The increased oxidative stress in subjects with type 2 diabetes is a consequence of several abnormalities, including hyperglycemia, insulin resistance, hyperinsulinemia, and dyslipidemia, each of which contributes to mitochondrial superoxide overproduction in endothelial cells of large and small vessels as well as the myocardium. The unifying pathophysiological mechanism that underlies diabetic complications could be explained by increased production of reactive oxygen species (ROS) via: (1) the polyol pathway flux, (2) increased formation of advanced glycation end products (AGEs), (3) increased expression of the receptor for AGEs, (4) activation of protein kinase C isoforms, and (5) overactivity of the hexosamine pathway. Furthermore, the effects of oxidative stress in individuals with type 2 diabetes are compounded by the inactivation of two critical anti-atherosclerotic enzymes: endothelial nitric oxide synthase and prostacyclin synthase. Of interest, the results of clinical trials in patients with type 2 diabetes in whom intensive management of all the components of the metabolic syndrome (hyperglycemia, hypercholesterolemia, and essential hypertension) was attempted (with agents that exert a beneficial effect on serum glucose, serum lipid concentrations, and blood pressure, respectively) showed a decrease in adverse cardiovascular end points. The purpose of this review is (1) to examine the mechanisms that link oxidative stress to micro- and macrovascular complications in subjects with type 2 diabetes and (2) to consider the therapeutic opportunities that are presented by currently used therapeutic agents which possess antioxidant properties as well as new potential antioxidant substances.

Prednisone versus tamoxifen in patients with idiopathic retroperitoneal fibrosis: an open-label randomised controlled trial

BACKGROUND Glucocorticoids are the mainstay of treatment of idiopathic retroperitoneal fibrosis, but they often have substantial toxic effects. Several reports have suggested tamoxifen as an alternative to glucocorticoids. We compared the efficacy of prednisone with that of tamoxifen in maintainance of remission in patients with idiopathic retroperitoneal fibrosis. METHODS In this open-label, randomised controlled trial, we enrolled patients aged 18-85 years with newly diagnosed idiopathic retroperitoneal fibrosis at the Parma Hospital, Parma, Italy, between Oct 1, 2000, and June 30, 2006. After induction therapy with 1 mg/kg daily of prednisone for 1 month, the patients who achieved remission were randomly assigned to receive tapering prednisone (initial dose 0·5 mg/kg daily) for 8 months or tamoxifen (fixed dose 0·5 mg/kg daily) for 8 months. The sequence of randomisation (1:1), blocked in groups of two and four (with block size randomly selected), was generated by the trial statistician with a computer programme. After the end of treatment, the patients were followed up for an additional 18 months. Neither patients nor those giving interventions or analysing the data were masked to group assignment. The two radiologists who assessed CT and MRI scans were masked. The primary endpoint was the relapse rate by the end of treatment (month 8), which was analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00440349. FINDINGS After induction therapy, 36 of the 40 enrolled patients achieved remission and were randomly assigned to treatment (18 per group). One patient (6%) in the prednisone group and seven patients (39%) in the tamoxifen group relapsed by the end of treatment (difference -33% [95% CI -58 to -8, p=0·0408]. The difference in relapse rate between the groups was sustained after the additional 18-month follow-up: the 26-month estimated cumulative relapse probability was 17% with prednisone and 50% with tamoxifen (difference -33% [-62 to -3, p=0·0372]). Cushingoid changes and grade 2 hypercholesterolaemia were more common in the prednisone group than in the tamoxifen group (p=0·0116 and p=0·0408, respectively). INTERPRETATION Prednisone is more effective in prevention of relapses than is tamoxifen in patients with idiopathic retroperitoneal fibrosis. Therefore, prednisone should be considered as first-line treatment for patients with newly diagnosed idiopathic retroperitoneal fibrosis. FUNDING Parma University Hospital.

Ear, nose and throat manifestations of Churg-Strauss syndrome

Conclusion. Ear, nose and throat (ENT) involvement is common in Churg-Strauss syndrome (CSS), usually manifesting as allergic rhinitis and chronic rhinosinusitis with or without polyps. Otolaryngologists may play a pivotal role in making an early diagnosis of this disease. Objectives. CSS is a systemic vasculitic disorder that affects small to medium-sized blood vessels. Although the cause of CSS remains unknown, tissue damage seems more likely to be mediated by activated eosinophils. Patients affected by CSS frequently have ENT manifestations, which are often present at the time of disease onset and may represent relevant clues for the diagnosis. Thus, our objective was to present the ENT manifestations at the onset, at the diagnosis and at some point during the course of the disease in a series of patients with CSS collected at a single center. Materials and methods. Twenty-eight patients with CSS, as defined according to the 1990 American College of Rheumatology classification criteria, were identified. Twenty-one (75%) of these patients had ENT involvement. We evaluated the clinical course, laboratory data, histologic findings, treatment and outcomes. Results. Of the 21 patients, 13 (61.9%) had ENT involvement at asthma onset and 8 (38%) at diagnosis or during follow-up. The most common ENT manifestations were allergic rhinitis in 9 (42.8%) patients and nasal polyposis in 16 (76.1%). Three (14.2%) patients developed chronic rhinosinusitis without polyps, three (14.2%) had nasal crusting, one (4.7%) serous otitis media, one (4.7%) purulent otitis media, two (9.5%) progressive sensorineural hearing loss, and one (4.7%) unilateral facial palsy. Corticosteroid therapy associated with immunosuppressive drugs usually yielded improvement or stabilization.

Structural remodeling in atrial fibrillation

Atrial fibrillation occurs and maintains itself in the context of a morphologically and functionally altered atrial substrate that can be induced by stressors such as underlying diseases (cardiac or noncardiac) or aging. The resultant structural remodeling is a slow process that progressively affects myocytes and the myocardial interstitium, and takes place from as early as the first days of atrial tachyarrhythmia. The left atrium, and particularly its posterior wall, is the location where remodeling is concentrated to the greatest extent. The mechanisms that underlie the remodeling process in atrial fibrillation have not yet been completely elucidated, although experimental and clinical investigations have indicated a number of signaling systems, inflammation, oxidative stress, atrial stretching and ischemia as factors involved in the cascade of events that leads to atrial fibrillation. The aim of this Review is to provide a comprehensive overview of the morphological changes that characterize the fibrillating atrial myocardium at histological and ultrastructural levels, and the established and hypothetical pathogenetic mechanisms involved in structural remodeling. This article also highlights the emerging therapies being developed to prevent progression of atrial fibrillation.

Role of Podocyte B7-1 in Diabetic Nephropathy

Podocyte injury and resulting albuminuria are hallmarks of diabetic nephropathy, but targeted therapies to halt or prevent these complications are currently not available. Here, we show that the immune-related molecule B7-1/CD80 is a critical mediator of podocyte injury in type 2 diabetic nephropathy. We report the induction of podocyte B7-1 in kidney biopsy specimens from patients with type 2 diabetes. Genetic and epidemiologic studies revealed the association of two single nucleotide polymorphisms at the B7-1 gene with diabetic nephropathy. Furthermore, increased levels of the soluble isoform of the B7-1 ligand CD28 correlated with the progression to ESRD in individuals with type 2 diabetes. In vitro, high glucose conditions prompted the phosphatidylinositol 3 kinase-dependent upregulation of B7-1 in podocytes, and the ectopic expression of B7-1 in podocytes increased apoptosis and induced disruption of the cytoskeleton that were reversed by the B7-1 inhibitor CTLA4-Ig. Podocyte expression of B7-1 was also induced in vivo in two murine models of diabetic nephropathy, and treatment with CTLA4-Ig prevented increased urinary albumin excretion and improved kidney pathology in these animals. Taken together, these results identify B7-1 inhibition as a potential therapeutic strategy for the prevention or treatment of diabetic nephropathy.

Cardiac hypertrophy and microvascular deficit in kinin B2 receptor knockout mice.

Abstract—Experimental and clinical evidence suggests kinin involvement in adaptive myocardial growth. Kinins are growth-inhibitory to cardiomyocytes. Knockout of kinin B2 receptor (B2R) signaling causes dilated and failing cardiomyopathy in 129/J mice, and a 9-bp deletion polymorphism of human B2R is associated with reduced receptor expression and exaggerated left ventricular growth response to physical stress. We reasoned that genetic background and aging may significantly influence the impact of B2R mutation on cardiac phenotype. The theory was challenged in C57BL/6 mice, a strain that naturally differs from the 129/J strain, carrying 1 instead of 2 renin genes. C57BL/6 B2R knockouts (B2R-KO) showed higher blood pressure and heart rate levels (P <0.05) compared with wild-type controls (WT) at all ages examined. At 12 months, left ventricular contractility and diastolic function were mildly altered (P <0.05) and histological and morphological analyses revealed ventricular hypertrophy and cardiomyocyte enlargement in B2R-KO (P <0.01). Reparative fibrosis was enhanced by 208% and capillary density reduced by 38% (P <0.01). Functional and structural alterations induced by B2R deletion in C57BL/6 mice were less severe than those reported previously in the 129/J strain. We conclude that interaction of B2R signaling with other genetic determinants influences aging-related changes in myocardial structure and function. These findings may help us understand the role of kinins in the development of cardiac failure.