The role of inflammation and metabolic risk factors in the pathogenesis of calcific aortic valve stenosis.

Given the epidemiologic increase of aged population in the world, aortic stenosis (AS) represents now the most common valvular heart disease in industrialized countries. It is a very challenging disease, representing an important cause of morbidity, hospitalization and death in the elderly population. It is widely recognized that AS is the result of a very complex active process, driven by inflammation and involving multifactorial pathological mechanisms promoting valvular calcification and valvular bone deposition. Several evidence suggest that epicardial adipose tissue (EAT), the visceral fat depot of the heart, represents a direct source of cytokines and could mediate the deleterious effects of systemic inflammation on the myocardium. Importantly, obesity and metabolic disorders are associated with chronic systemic inflammation leading to a significant increase of EAT amount and to a pro-inflammatory phenotypic shift of this fat depot. It has been hypothesized that the EAT inflammatory state can influence the structure and function of the heart, thus contributing to the pathogenesis of several cardiac diseases, including calcific AS. The current review will discuss the recently discovered mechanisms involved in the pathogenesis of AS, with particular attention to the role of inflammation, metabolic risk factors and pro-fibrotic and pro-osteogenic signal pathways promoting the onset and progression of the disease. Moreover, it will be explored the potential role of EAT in the AS pathophysiology.

Imbalance Between Interleukin-1ß and Interleukin-1 Receptor Antagonist in Epicardial Adipose Tissue Is Associated With Non ST-Segment Elevation Acute Coronary Syndrome.

INTRODUCTION: Interleukin-1beta (IL-1ß) is crucially involved in the pathogenesis of coronary atherosclerotic diseases (CAD) and its inhibition has proven cardiovascular benefits. Epicardial adipose tissue (EAT) is a local source of inflammatory mediators which may negatively affect the surrounding coronary arteries. In the present study, we explored the relationship between serum and EAT levels of IL-1ß and IL-1 receptor antagonist (IL-1ra) in patients with chronic coronary syndrome (CCS) and recent acute coronary syndrome (ACS). METHODS: We obtained EAT biopsies in 54 CCS (Group 1) and 33 ACS (Group 2) patients undergoing coronary artery bypass grafting. Serum and EAT levels of IL-1ß and IL-1ra were measured in all patients. An immunophenotypic study was carried out on EAT biopsies and the CD86 events were studied as markers of M1 macrophages. RESULTS: Circulating levels of IL-1ß were significantly higher in the overall CAD population compared to a control group [7.64 pg/ml (6.86; 8.57) vs. 1.89 pg/ml (1.81; 2.29); p < 0.001]. In contrast, no differences were observed for serum IL-1ra levels between CAD and controls. Comparable levels of serum IL-1ß were found between Groups 1 and 2 [7.6 pg/ml (6.9; 8.7) vs. 7.9 pg/ml (7.2; 8.6); p = 0.618]. In contrast, significantly lower levels of serum IL-1ra were found in Group 2 compared to Group 1 [274 pg/ml (220; 577) vs. 603 pg/ml (334; 1022); p = 0.035]. No differences of EAT levels of IL-1ß were found between Group 2 and Group 1 [3.4 pg/ml (2.3; 8.4) vs. 2.4 pg/ml (1.9; 8.0); p = 0.176]. In contrast, significantly lower EAT levels of IL-1ra were found in Group 2 compared to Group 1 [101 pg/ml (40; 577) vs. 1344 pg/ml (155; 5327); p = 0.002]. No correlation was found between EAT levels of IL-1ß and CD86 and CD64 events. CONCLUSION: The present study explores the levels of IL-1ß and IL-1ra in the serum and in EAT of CCS and ACS patients. ACS seems to be associated to a loss of the counter-regulatory activity of IL-1ra against the pro-inflammatory effects related to IL-1ß activation.

Echocardiographic Epicardial Adipose Tissue Thickness for Risk Stratification of Patients With Heart Failure.

BACKGROUND AND AIMS: Epicardial adipose tissue (EAT) has been shown to be involved in the pathogenesis and progression of heart failure (HF). In this study we aimed to explore the predictive value of echocardiographic EAT thickness on prognosis of a selected population of HF patients. METHODS: The patient population included n. 69 consecutive patients with systolic HF referred to implantable cardioverter defibrillator (ICD) implantation for primary or secondary prevention. At the time of enrolment, echocardiographic EAT thickness was assessed in all patients along with demographic and clinical data. The study had a median follow-up time of 49.8 months. We assessed the prognostic predictive value of EAT thickness on a composite clinical and arrhythmic outcome including HF related deaths, new hospital admissions for HF worsening, and atrial and life threatening ventricular arrhythmic events. Clinical and arrhythmic outcomes were also evaluated separately. RESULTS: At univariate analysis, EAT thickness significantly predicted all the three outcomes considered. Of interest, at multivariate analysis, after adjusting for known risk factor, EAT remained significantly associated to the composite [HR 1.18 (1.09-1.28); p < 0.001], arrhythmic [HR 1.14 (1.03-1.25); p = 0.008], and clinical [HR 1.14 (1.03-1.27); p = 0.010] outcomes. CONCLUSION: Echocardiographic assessment of EAT can predict outcome of HF patients and it is significantly associated with both arrhythmic and clinical events. These preliminary findings pave the way for future and larger studies aimed to definitively recognize the prognostic value of this novel risk marker in HF.

Statin therapy modulates thickness and inflammatory profile of human epicardial adipose tissue.

BACKGROUND: Epicardial adipose tissue (EAT) thickness and pro-inflammatory status has been shown to be associated with several cardiac diseases, including aortic stenosis (AS). Thus, cardiac visceral fat could represent a potential new target for drugs. In the present study we evaluate the effect of statin therapy on EAT accumulation and inflammation. METHODS: Echocardiographic EAT thickness was assessed in 193 AS patients taking (n.87) and not taking (n.106) statins, undergoing cardiac surgery. To explore the association between statin therapy and EAT inflammation, EAT biopsies were obtained for cytokines immunoassay determination in EAT secretomes. An in vitro study was also conducted and the modulation of EAT and subcutaneous adipose tissue (SCAT) secretomes by atorvastatin was assessed in paired biopsies. RESULTS: Statin therapy was significantly associated with lower EAT thickness (p < 0.0001) and with lower levels of EAT-secreted inflammatory mediators (p < 0.0001). Of note, there was a significant correlation between EAT thickness and its pro-inflammatory status. In vitro, atorvastatin showed a direct anti-inflammatory effect on EAT which was significantly higher compared to the SCAT response to statin incubation (p < 0.0001). CONCLUSIONS: The present study indicates a robust association between statin therapy and reduced EAT accumulation in patients with AS. The present data also suggest a direct relationship between EAT thickness and its inflammatory status, both modulated by statin therapy. The in vitro results support the hypothesis of a direct action of statins on EAT secretory profile. Overall our data suggest EAT as a potential new therapeutic target for statin therapy.

Left atrial dilatation: A target organ damage in young to middle-age hypertensive patients. The Campania Salute Network.

BACKGROUND: Left atrial (LA) volume is a predictor of outcome in hypertension. It is unclear whether or not this effect depends on coexisting target organ damage (TOD). PURPOSE: To investigate whether LA volume predicts outcome independently of TOD [left ventricular (LV) hypertrophy (LVH) and/or carotid plaque] in a registry of hypertensive treated patients. METHODS: From the Campania Salute Network registry, we selected 5844 young adult hypertensive patients <65 years old (mean age 50 ±â€¯9 years, 41% women, 8% diabetic) without prevalent CV or valvular heart disease more than mild, with normal LV ejection fraction, stage III or less CKD and available follow-up. LA volume was estimated from LA diameter applying a validated nonlinear equation, and indexed to body height in meters to the second power (eLAVI). Composite fatal and non-fatal stroke, myocardial infarction, sudden cardiac death, heart failure, TIA, myocardial revascularization, de novo angina, carotid stenting or atrial fibrillation (AF) were adjudicated as incident CV events. RESULTS: 565 (10%) patients exhibited dilated initial eLAVI. During a median follow-up of 49 months, 233 patients developed CV events. Multivariable Cox regression analysis, demonstrated that dilated eLAVI increased risk of incident composite CV events (HR 1.90, 95%CI 1.26-2.88, p = 0.002), independently of significant effect of older age, male sex, presence LVH and carotid plaque. Conclusions In middle aged, treated hypertensive patients, dilated eLAVI is associated with adverse CV risk profile and is a predictor of CV events independently of other markers of TOD. LA dilatation should be considered as a TOD.

Three-dimensional echocardiographic ventricular mass/end-diastolic volume ratio in native hypertensive patients: relation between stroke volume and geometry.

BACKGROUND: Elevated left ventricular (LV) mass/end-diastolic volume ratio (LVM/EDV) has been associated with higher evidence of myocardial fibrosis and dysfunction in hypertensive patients by cardiac magnetic resonance, a technique with limited availability. OBJECTIVES: We investigated the ability of three-dimensional (3D) echocardiography in identifying a phenotype of LV concentric geometry according to LVM/EDV ratio, possibly detecting early myocardial damage in native-hypertensive patients. METHODS: One hundred and twenty-eight native-hypertensive patients underwent 2D and 3D-echocardiography. The population was divided into two groups, according to cut-off point values of 3D-LVM/EDV ratio corresponding to its upper 95% confidence interval in a population of 90 healthy normotensive individuals: LVM/EDV ratio cut-off was 1.22 in men and 1.23 in women. RESULTS: An increased 3D-LVM/EDV ratio identified a higher rate of LV concentric geometry in comparison with 2D-derived relative wall thickness (37 versus 24%, P = 0.03). Patients with LVM/EDV ratio of 1.22 or more in men and 1.23 or more in women were significantly older, had smaller 3D-LV end-diastolic and end-systolic volumes and higher LV mass index, without difference in ejection fraction. 3D-stroke volume (P < 0.0001) was lower in patients with elevated LVM/EDV ratio. By a multilinear regression analysis, after adjusting for sex, age, heart rate, mean blood pressure and BMI, stroke volume was independently and negatively associated to LVM/EDV ratio (ß = -0.55, P < 0.0001). CONCLUSION: In native hypertensive patients, 3D-echo-derived LVM/EDV ratio identifies a higher prevalence of LV concentric geometry than 2D-relative wall thickness. Stroke volume is independently and negatively associated with LVM/EDV ratio and its reduction represents an early marker of myocardial dysfunction in hypertensives with LV concentric geometry.

Increased Epicardial Adipose Tissue Volume Correlates With Cardiac Sympathetic Denervation in Patients With Heart Failure.

RATIONALE: It has been reported that epicardial adipose tissue (EAT) may affect myocardial autonomic function. OBJECTIVE: The aim of this study was to explore the relationship between EAT and cardiac sympathetic nerve activity in patients with heart failure. METHODS AND RESULTS: In 110 patients with systolic heart failure, we evaluated the correlation between echocardiographic EAT thickness and cardiac adrenergic nerve activity assessed by (123)I-metaiodobenzylguanidine ((123)I-MIBG). The predictive value of EAT thickness on cardiac sympathetic denervation ((123)I-MIBG early and late heart:mediastinum ratio and single-photon emission computed tomography total defect score) was tested in a multivariate analysis. Furthermore, catecholamine levels, catecholamine biosynthetic enzymes, and sympathetic nerve fibers were measured in EAT and subcutaneous adipose tissue biopsies obtained from patients with heart failure who underwent cardiac surgery. EAT thickness correlated with (123)I-MIBG early and late heart:mediastinum ratio and single-photon emission computed tomography total defect score, but not with left ventricular ejection fraction. Moreover, EAT resulted as an independent predictor of (123)I-MIBG early and late heart:mediastinum ratio and single-photon emission computed tomography total defect score and showed a significant additive predictive value on (123)I-MIBG planar and single-photon emission computed tomography results over demographic and clinical data. Although no differences were found in sympathetic innervation between EAT and subcutaneous adipose tissue, EAT showed an enhanced adrenergic activity demonstrated by the increased catecholamine levels and expression of catecholamine biosynthetic enzymes. CONCLUSIONS: This study provides the first evidence of a direct correlation between increased EAT thickness and cardiac sympathetic denervation in heart failure.