George Chalikias

Associations Between Collagen Synthesis and Degradation and Aortic Function in Arterial Hypertension

BACKGROUND Studies have suggested that collagen accumulation in the aortic wall may contribute to the stiff aorta in arterial hypertension. However, data in human hypertension are limited. In this investigation, relations between markers of collagen metabolism and aortic function in patients with arterial hypertension were evaluated. METHODS We studied 72 hypertensive patients (age 53 +/- 5 years) and 27 age- and gender-matched normotensive individuals. Elastic properties of the aorta were assessed by aortic pulse wave velocity (carotid-to-femoral pulse wave velocity (PWVc-f)). Free amino-terminal propeptides of precollagen type I (PINP, reflecting collagen I synthesis), serum telopeptides of collagen type I (CITP, an index of collagen I degradation), free amino-terminal propeptides on precollagen type III (PIIINP, reflecting collagen III metabolism), prometalloproteinase-1 (proMMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined by commercially available immunoassays. RESULTS Patients with arterial hypertension had greater PWVc-f (P = 0.01); and higher levels of PINP/CITP compared to control (P = 0.04). PWVc-f was significantly associated with PINP/CITP ratio (analysis of variance (ANOVA), P = 0.03). Hypertensive patients had significantly higher levels of proMMP-1/TIMP-1 (P = 0.04); PWVc-f was significantly associated with proMMP-1 (ANOVA, P = 0.03) and proMMP-1/TIMP-1 (ANOVA, P = 0.04). Associations between PWVc-f and proMMP-1 and between PWVc-f and PINP/CITP ratio remained significant after adjustment for PWVc-f confounders and antihypertensive treatment. CONCLUSIONS Alterations in collagen turnover that favor collagen type I synthesis; as well as proMMP-1 expression are related to increased aortic stiffness in treated hypertensive individuals without left ventricular (LV) hypertrophy.

Oxidised low‐density lipoprotein and arterial function in β‐thalassemia major

Objectives:  Vascular abnormalities such as endothelial dysfunction and arterial stiffness have been described in patients with β‐thalassemia major (β‐TM). Increased concentrations of oxidised low‐density lipoprotein cholesterol (oxLDL) have been observed in those patients, but possible associations between oxLDL and arterial function in β‐TM have not been defined.

Prevention of Contrast-Induced Acute Kidney Injury: an Update

Contrast-induced acute kidney injury (CI-AKI) is a common complication of intravascular administration of contrast media used in coronary angiography, percutaneous coronary intervention and other diagnostic and interventional procedures. This review article aims at summarizing the published literature regarding the prevention of CI-AKI, by focusing on available high-quality meta-analyses addressing this matter. Apart from adequate hydration, a number of pharmacologic agents have been proposed as potential candidates to be included in the routine preparation, prior to the patient’s arrival in the cardiac catheterization laboratory. Among them, statins and N-acetylcysteine appear to be the most extensively studied ones. Throughout this article we present the available data on CI-AKI prevention and provide a critical clinical appraisal, as well as a summary of currently available guidelines.

Plasma leptin and adiponectin concentrations in healthy, non-obese children

Abstract Background: Alterations in plasma leptin and adiponectin concentrations are associated with an adverse metabolic profile in obese children. Objective: To simultaneously assess multiple factors with possible effects on plasma leptin and adiponectin concentrations in healthy, non-obese children. Subjects: We studied 170 healthy non-obese children (86 males, age 10±1.5 years), with available medical records from birth. Methods: Plasma leptin and adiponectin concentrations were assessed by immunoassay. The ratio of current weight/birth weight (WBWR) was used as an index of children growth from birth. Children’s intensity of physical activity and parental characteristics were also assessed. Results: Leptin was positively associated with WBWR (p<0.0001); parental smoking (analysis of variance, ANOVA; p=0.03) and parental obesity (ANOVA; p<0.001) were negatively associated with breastfeeding (p<0.01) and children’s access to exercise (p<0.0001). Adiponectin was negatively associated with WBWR (p<0.0001) and parental smoking (p=0.04), with an additive negative effect of parental smoking status and parental obesity on children’s adiponectin levels (ANOVA; p=0.02). Conclusions: Children’s and parental factors are related and could possibly influence leptin and adiponectin concentrations in healthy non-obese children. Early preventive strategies that target both children and parents could improve the profile of adipocytokine in these children.

Acute Phase Treatment of Pulmonary Embolism

Pulmonary embolism (PE) is a common and potentially life threatening disease if left untreated. This is due to a natural tendency towards early recurrence of pulmonary emboli which may lead to right ventricular failure. Thus, anticoagulant treatment should be administered to all patients upon high or intermediate clinical probability of acute PE, while awaiting definitive confirmation by imaging procedures. With the exception of severe renal impairment, high bleeding risk, arterial hypotension, and extremes of body weight and age, unfractionated heparin has been replaced by low molecular-weight heparin or fondaparinux given subcutaneously at weight-adjusted doses. In hemodynamically unstable patients with confirmed (high-risk) PE, thrombolysis should be administered without delay; if thrombolysis is absolutely contraindicated or has failed, surgical embolectomy or catheter-based thrombus removal is a valuable alternative. In normotensive (non-high-risk) patients, low-molecular-weight heparin or fondaparinux is adequate treatment in most cases, and thrombolysis is generally not recommended as a first-line therapeutic option. An ongoing randomized trial will determine whether normotensive patients with evidence of right ventricular dysfunction plus myocardial injury may benefit from early thrombolysis. Finally, selected normotensive patients without serious comorbidity or signs of heart failure (low-risk PE) may be candidates for out-of-hospital treatment. This strategy may be facilitated by the use of new oral anticoagulants in the future.

The Incidence and the Prognostic Impact of Acute Kidney Injury in Acute Myocardial Infarction Patients: Current Preventive Strategies

Acute kidney injury (AKI) is one of the most common complications during hospitalization in various clinical settings. The goal of this review was to assess the incidence of AKI in acute myocardial infarction patients (AMI), how this incidence is affected by the diverse definitions, and if there is variability in the reported rates over recent years. Additionally, we sought to appraise the impact of AKI on short- and long-term prognosis of these patients. Finally, we report on the current preventive measures as they are suggested in the current guidelines of various societies, we comment on the evidence that support them, and we review the literature for other proposed therapeutic strategies, which either failed to prove their efficacy or they are not adequately confirmed yet. Due to the heterogeneity in AKI definition and in the population studied of the published data, the incidence of AKI ranged from 5.2 to 59%. A recent meta-analysis reported a median value of 15.8%. All studies assessing AKI-related prognosis in AMI patients suggested that presence of AKI has detrimental effect on patients prognosis, raising mortality two- to threefold not only during the 30 first days but also during the first year after the acute event. Various treatment modalities have been proposed for prevention of AKI in AMI patients; however, the majority of them failed to prove their efficacy in the clinical trial arena. Hydration, use of iso- or low-osmolar agents at the lowest possible dose during coronary interventions, and use of statins have been proposed among others. Nonetheless, the prevalence of AKI after an AMI still remains high today and therefore it is crucial for the practicing physician to be aware of its presence and for the scientific community to identify novel measures for a more efficacious prevention.

Serum calcification propensity is independently associated with disease activity in systemic lupus erythematosus

Background Systemic lupus erythematosus (SLE) is associated with severe cardiovascular complications. The T50 score is a novel functional blood test quantifying calcification propensity in serum. High calcification propensity (or low T50) is a strong and independent determinant of all-cause mortality in various patient populations. Methods A total of 168 patients with ≥ 4 American College of Rheumatology (ACR) diagnostic criteria from the Swiss Systemic lupus erythematosus Cohort Study (SSCS) were included in this analysis. Serum calcification propensity was assessed using time-resolved nephelometry. Results The cohort mainly consisted of female (85%), middle-aged (43±14 years) Caucasians (77%). The major determinants of T50 levels included hemoglobin, serum creatinine and serum protein levels explaining 43% of the variation at baseline. Integrating disease activity (SELENA-SLEDAI) into this multivariate model revealed a significant association between disease activity and T50 levels. In a subgroup analysis considering only patients with active disease (SELENA-SLEDAI score ≥4) we found a negative association between T50 and SELENA-SLEDAI score at baseline (Spearman’s rho -0.233, P = 0.02). Conclusions Disease activity and T50 are closely associated. Moreover, T50 levels identify a subgroup of SLE patients with ongoing systemic inflammation as mirrored by increased disease activity. T50 could be a promising biomarker reflecting SLE disease activity and might offer an earlier detection tool for high-risk patients.

Cardiovascular Implications of Sphingomyelin Presence in Biological Membranes

Sphingomyelin (SM) is a type of sphingolipid found within plasma, cellular membranes and plasma lipoproteins. Here we highlight the basic biochemical features of SMs and their role in biological membranes. We further discuss evidence of the association between SM and cardiovascular diseases such as atherosclerosis, valvular disease, heart failure and diabetes mellitus.

COMPARISON OF CIN RISK PREDICTION MODELS: A PROSPECTIVE COHORT STUDY

Background: Contrast-induced nephropathy (CIN) is a frequent, potentially lethal complication of percutaneous coronary interventions (PCI). We prospectively validated the diagnostic performance of all published risk scores in a cohort of patients undergoing PCI. Methods: We enrolled 602 consecutive

Novel echocardiographic prognostic markers for cardiac tamponade in patients with large malignant pericardial effusions: A paradigm shift from flow to tissue imaging

With this study, we sought to investigate the prognostic value of echocardiographic tissue imaging markers in predicting tamponade among patients with large malignant pericardial effusion compared to routinely used echocardiographic signs.