Rosetta Ragusa

IL-33/ST2 Pathway and Classical Cytokines in End-Stage Heart Failure Patients Submitted to Left Ventricular Assist Device Support: A Paradoxic Role for Inflammatory Mediators?

Background. Inflammation is a critical process contributing to heart failure (HF). We hypothesized that IL-33/ST2 pathway, a new mechanism regulated during cardiac stress, may be involved in the functional worsening of end-stage HF patients, candidates for left ventricular assist device (LVAD) implantation, and potentially responsible for their outcome. Methods. IL-33, ST2, and conventional cytokines (IL-6, IL-8, and TNF-α) were determined in cardiac biopsies and plasma of 22 patients submitted to LVAD implantation (pre-LVAD) and compared with (1) control stable chronic HF patients on medical therapy at the moment of heart transplantation without prior circulatory support (HT); (2) patients supported by LVAD at the moment of LVAD weaning (post-LVAD). Results. Cardiac expression of ST2/IL-33 and cytokines was lower in the pre-LVAD than in the HT group. LVAD determined an increase of inflammatory mediators comparable to levels of the HT group. Only ST2 correlated with outcome indices after LVAD implantation. Conclusions. IL-33/ST2 and traditional cytokines were involved in decline of cardiac function of ESHF patients as well as in hemodynamic recovery induced by LVAD. IL-33/ST2 pathway was also associated to severity of clinical course. Thus, a better understanding of inflammation is the key to achieving more favorable outcome by new specific therapies.

Effect of Coronary Atherosclerosis and Myocardial Ischemia on Plasma Levels of High-Sensitivity Troponin T and NT-proBNP in Patients With Stable Angina.

Objective— Circulating levels of high-sensitivity cardiac troponin T (hs-cTnT) and N terminal pro brain natriuretic peptide (NT-proBNP) are predictors of prognosis in patients with coronary artery disease (CAD). We aimed at evaluating the effect of coronary atherosclerosis and myocardial ischemia on cardiac release of hs-cTnT and NT-proBNP in patients with suspected CAD. Approach and Results— Hs-cTnT and NT-proBNP were measured in 378 patients (60.1±0.5 years, 229 males) with stable angina and unknown CAD enrolled in the Evaluation of Integrated Cardiac Imaging (EVINCI) study. All patients underwent stress imaging to detect myocardial ischemia and coronary computed tomographic angiography to assess the presence and characteristics of CAD. An individual computed tomographic angiography score was calculated combining extent, severity, composition, and location of plaques. In the whole population, the median (25–75 percentiles) value of plasma hs-cTnT was 6.17 (4.2–9.1) ng/L and of NT-proBNP was 61.66 (31.2–132.6) ng/L. In a multivariate model, computed tomographic angiography score was an independent predictor of the plasma hs-cTnT (coefficient 0.06, SE 0.02; P=0.0089), whereas ischemia was a predictor of NT-proBNP (coefficient 0.38, SE 0.12; P=0.0015). Hs-cTnT concentrations were significantly increased in patients with CAD with or without myocardial ischemia (P<0.005), whereas only patients with CAD and ischemia showed significantly higher levels of NT-proBNP (P<0.001). Conclusions— In patients with stable angina, the presence and extent of coronary atherosclerosis is related with circulating levels of hs-cTnT, also in the absence of ischemia, suggesting an ischemia-independent mechanism of hs-cTnT release. Obstructive CAD causing myocardial ischemia is associated with increased levels of NT-proBNP.

Plasma cardiac troponin I concentrations in healthy neonates, children and adolescents measured with a high sensitive immunoassay method: High sensitive troponin I in pediatric age.

Over the past 10years cardiac troponin (cTn) immunoassays have been improved in analytical sensitivity and precision thereby allowing the measurement of cTn in adult healthy subjects. However, there are currently substantial gaps in our knowledge on circulating levels of cTn in healthy children. The aim of this study is to evaluate the distribution of plasma troponin concentration in apparently healthy pediatric subjects using a high sensitive immunoassay for cTnI measurement (hs-cTnI). Blood samples were obtained from 357 healthy pediatric subjects [204 males; age range 0-18years; mean (SD): 8.7(6) years], including 36 subjects aged <1month (neonates), 57 between 1 and 12months (infants), 65 between 1 and 10years (toddlers), and 223 between 10 and 18years (adolescents). The percentages of healthy population with cTnI values equal or less than the calculated and LOD value were 13.1%. cTnI plasma levels were highest in the first month of life with a progressive decline in the next years and were lower in female. At multivariate analysis, only age was predictor of hs-cTnI plasma levels. The age and sex of children influence normal and physiologically released circulating concentrations of hs-cTnI, suggesting the need of reference intervals specific for age and sex.

Uncovering the cathepsin system in heart failure patients submitted to Left Ventricular Assist Device (LVAD) implantation.

BackgroundIn end-stage heart failure (HF), the implantation of a left ventricular assist device (LVAD) is able to induce reverse remodeling. Cellular proteases, such as cathepsins, are involved in the progression of HF. The aim of this study was to evaluate the role of cathepsin system in HF patients supported by LVAD, in order to determine their involvement in cardiac remodeling.MethodsThe expression of cysteine (CatB, CatK, CatL, CatS) and serine cathepsin (CatG), and relative inhibitors (Cystatin B, C and SerpinA3, respectively) was determined in cardiac biopsies of 22 patients submitted to LVAD (pre-LVAD) and compared with: 1) control stable chronic HF patients on medical therapy at the moment of heart transplantation without prior LVAD (HT, n = 7); 2) patients supported by LVAD at the moment of transplantation (post-LVAD, n = 6).ResultsThe expression of cathepsins and their inhibitors was significantly higher in pre-LVAD compared to the HT group and LVAD induced a further increase in the cathepsin system. Significant positive correlations were observed between cardiac expression of cathepsins and their inhibitors as well as inflammatory cytokines. In the pre-LVAD group, a relationship of cathepsins with dilatative etiology and length of hospitalization was found.ConclusionsA parallel activation of cathepsins and their inhibitors was observed after LVAD support. The possible clinical importance of these modifications is confirmed by their relation with patients’ outcome. A better discovery of these pathways could add more insights into the cardiac remodeling during HF.

Effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver: study in the experimental model of Zucker rats

Suppression of tumorigenicity 2 (ST2) mediates the effect of Interleukin-33 (IL-33). Few data are reported on the relationship between IL-33/ST2 and obesity. We aimed to investigate effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver in a rodent model of obesity. The relationship of cardiac expression of IL-33/ST2 system with natriuretic peptides (NPs) system and inflammatory mediators was also studied. mRNA expression of IL-33/ST2 system was evaluated in cardiac, adipose and hepatic biopsies from obese Zucker rats (O) and controls (CO). Expression levels of sST2 was significantly lower in O rats compared with CO (p<0.05) in all tissues. Besides, the mRNA levels of IL-33 decreased significant in fat of O respect to CO, while, expression levels of ST2L was significantly higher in liver of CO than in O. A strong relationship of IL-33/ST2 with NPs and classical inflammatory mediators was observed in cardiac tissue. Expression of sST2 in cardiac, adipose and liver tissue decreased in O compared with controls, suggesting an involvement for IL-33/ST2 system in molecular mechanisms of obesity. The strong relationships with NP systems and inflammatory mediators could suggest an involvement for IL-33/ST2 in molecular pathways leading to cardiac dysfunction and inflammation associated with obesity.

Distribution of circulating cardiac biomarkers in healthy children: from birth through adulthood.

AIM While circulating biomarkers are critical tools for cardiovascular adult care, their relevance in childhood is unknown. METHODS We evaluated the behavior of plasma concentrations of clinically relevant cardiac biomarkers (NT-proBNP, hs-cTnI, sST2, Galectin-3) in 106 healthy children. RESULTS Subjects were divided into age subgroups: 24 newborns (0-30 days), 26 infants (1-12 months), 30 children (1-12 years) and 26 adolescents (13-18 years). Healthy adults were used as control. NT-proBNP (newborns: 504.3 [211.07-942.7] ng/L, median [25-75 percentiles]; infants: 200.64 [76.88-306.73]; children: 97.27 [49.24-271.80]; adolescents: 24.35 [13.14-58.83]; p < 0.001) and hs-cTnI (newborns: 9.3 [3.3-93.8] ng/L; infants: 13.8 [4.82-72.52]; children: 11.45 [4.0-48.10]; adolescents: 2.6[2.07-3.90]; p < 0.001) were highest in the first month of life, showing a decline in the next years. sST2 and Galectin-3 showed no differences. CONCLUSION Changes in hs-cTnI and NT-proBNP suggest the design of age- and sex-based reference intervals that will have to be explored in a larger population.

Time-course of circulating cardiac and inflammatory biomarkers after Ventricular Assist Device implantation: Comparison between paediatric and adult patients

BACKGROUND Ventricular Assist Device (VAD) as bridge to transplantation is a common therapy for adult with heart failure (HF), but VAD use is increasing also in children. Cardiac and inflammatory biomarkers have an important role in the diagnosis and prognosis of HF in adults, but their role in paediatric setting is unknown. The aim of this study was to examine changes in cardiac and inflammatory biomarkers, both in HF paediatric and adult patients, before and following VAD. METHODS Cardiac (NT-proBNP, cTnI, sST2,Gal-3) and inflammatory (IL-6,IL-8) biomarkers were determined in plasma collected from 12 paediatric patients and 7 adult patients with HF, before and at 4 h,1,3,7,14 and 30 days after VAD implant. RESULTS All biomarkers increased up to 1 day after VAD implant and then decreased at pre-VAD levels in 1 month in both groups. Only in children, NT-proBNP decreased significantly after 30 days Post-VAD treatment compared to pre-VAD levels. During the post-operative time-course, NT-proBNP and sST2 were significantly higher in children than adults, while IL-6 was lower. CONCLUSIONS Cardiac and inflammatory biomarkers were differently modified by VAD implant in children compared to adults. These preliminary data could suggest that different molecular pathways may underlie HF patho-physiology of the two groups, possibly paving the way to a specific and targeted therapeutic intervention in the near future.