Search

Background Higher body mass index (BMI) is associated with better outcome compared with normal weight in patients with HF and other chronic diseases. It remains uncertain whether the apparent protective role of obesity relates to the absence of comorbidities. Therefore, we investigated the effect of BMI on outcome in younger patients without co-morbidities as compared to older patients with co-morbidities in a large heart failure (HF) population. Methods In an individual patient data analysis from pooled cohorts, 5,819 patients with chronic HF and data available on BMI, co-morbidities and outcome were analysed. Patients were divided into four groups based on BMI (i.e. ≤ 18.5 kg/m2, 18.5–25.0 kg/m2; 25.0–30.0 kg/m2; 30.0 kg/m2). Primary endpoints included all-cause mortality and HF hospitalization-free survival. Results Mean age was 65 ± 12 years, with a majority of males (78%), ischaemic HF and HF with reduced ejection fraction. Frequency of all-cause mortality or HF hospitalization was significantly worse in the lowest two BMI groups as compared to the other two groups; however, this effect was only seen in patients older than 75 years or having at least one relevant co-morbidity, and not in younger patients with HF only. After including medications and N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin concentrations into the model, the prognostic impact of BMI was largely absent even in the elderly group with co-morbidity. Conclusions The present study suggests that obesity is a marker of less advanced disease, but does not have an independent protective effect in patients with chronic HF. Graphic abstract Categories of BMI are only predictive of poor outcome in patients aged > 75 years or with at least one co-morbidity (bottom), but not in those aged

Background Postexercise release of cardiac troponin (cTn) is a well-known phenomenon, although the influence of various confounders remains unclear. The aim of this critical review was to analyze the postexercise release of cTn according to age, sex, different types of sport, exercise intensity and duration, and training level. Data sources A literature search was performed within the National Library of Medicine using the following keywords: cTn, peak, release, and exercise. The search was further refined by adding the keywords athletes, children/adolescents, and sport. Main results For final analysis, 52 studies were included: 43 adult studies, 4 pediatric studies, and 5 with a mixed population of adults and children. Several studies have investigated the kinetics of cTn response after exercise with different biomarkers. The current evidence suggests that sport intensity and duration have significant effects on postexercise cTn elevation, whereas the influence of the type of sport, age, and sex have been not completely defined yet. Most data were obtained during endurance races, whereas evidence is limited (or almost absent), particularly for mixed sports. Data on young adults and professional athletes are limited. Finally, studies on women are extremely limited, and those for non-White are absent. Conclusions Postexercise release of cTn can be observed both in young and master athletes and usually represents a physiological phenomenon; however, more rarely, it may unmask a subclinical cardiac disease. The influence of different confounders (age, sex, sport type/intensity/duration, and training level) should be better clarified to establish individualized ranges of normality for postexercise cTn elevation.

We assessed whether high triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) levels, expressed by an increased TG/HDL-C ratio, predict coronary atherosclerotic disease (CAD) outcomes in patients with stable angina. We studied 355 patients (60 ± 9 years, 211 males) with stable angina who underwent coronary computed tomography angiography (CTA), were managed clinically and followed for 4.5 ± 0.9 years. The primary composite outcome was all-cause mortality and non-fatal myocardial infarction. At baseline, the proportion of males, patients with metabolic syndrome, diabetes and obstructive CAD increased across TG/HDL-C ratio quartiles, together with markers of insulin resistance, hepatic and adipose tissue dysfunction and myocardial damage, with no difference in total cholesterol or LDL-C. At follow-up, the global CTA risk score (HR 1.06, 95% confidence interval (CI) 1.03–1.09, P = 0.001) and the IV quartile of the TG/HDL-C ratio (HR 2.85, 95% CI 1.30–6.26, P Trial registration. EVINCI study: ClinicalTrials.gov NCT00979199, registered September 17, 2009; SMARTool study: ClinicalTrials.gov NCT04448691, registered June 26, 2020.

Important advances achieved in pharmacological cancer treatment have led progressively to a reduction in mortality from many forms of cancer, and increasing numbers of previously incurable patients can now hope to become cancer-free. Yet, to achieve these improved outcomes a high price has been paid in terms of untoward side effects associated with treatment, cardio-toxicity in particular. Several recent studies have reported that cardiac troponin assay using high-sensitivity methods (hs-cTn) can enable the early detection of myocardial injury related to chemotherapy or abuse of drugs that are potentially cardiotoxic. Several authors have recently suggested that changes in hs-cTn values enable the early diagnosis of cardiac injury from chemotherapy, thus potentially benefitting cancer patients with increased troponin values by initiating early cardioprotective therapy. However, large randomised clinical trials are needed in order to evaluate the cost/benefit ratio of standardised protocols for the early detection of cardiotoxicity using the hs-cTn assay in patients treated with chemotherapy.

The measurement of cardiac troponin (cTn) is recommended by all guidelines as the gold standard for the differential diagnosis of Acute Coronary Syndromes. The aim of this review is to discuss in details some key issues regarding both analytical and clinical characteristics of the high-sensitivity methods for cTn (hs-cTn), which are still considered controversial or unresolved. In particular, the major clinical concern regarding hs-cTn methods is the difficulty to differentiate the pathophysiological mechanism responsible for biomarker release from cardiomyocytes after reversible or irreversible injury, respectively. Indeed, recent experimental and clinical studies have demonstrated that different circulating forms of cTnI and cTnT can be respectively measured in plasma samples of patients with reversible or irreversible myocardial injury. Accordingly, a new generation of hs-Tn methods should be set up, based on immunometric immunoassays or chromatographic techniques, specific for circulating peptide forms more characteristics for reversible or irreversible myocardial injury. It is conceivable that this new generation of hs-cTn methods will complete the mission regarding the laboratory tests for specific cardiac biomarkers, started more than 20 years ago, which has already revolutionized the diagnosis, prognosis and management of patients with cardiac diseases.

The high-sensitivity immunoassays for cardiac troponin I (hs-cTnI) and cardiac troponin T (hs-cTnT) are recommended by all the most recent international guidelines as gold standard laboratory methods for the detection of myocardial injury and diagnosis of acute myocardial infarction (AMI). In this review article, the Authors aimed at discussing the relevant biochemical, physiological, and clinical issues related to biological variability of cTnI and cTnT. Cardiac troponins, measured with hs-cTn methods, show a better clinical profile than the other cardio-specific biomarkers (such as the natriuretic peptides, BNP and NT-proBNP). In particular, the hs-cTn methods are characterized by a low intra-individual index of variation (30% can be considered statistically significant. These favourable biological characteristics and analytical performance of hs-cTn methods significantly improved the accuracy in the diagnostic process of acute coronary syndromes (ACS) in patients admitted to emergence department. In addition, several studies have demonstrated the clinical usefulness of cardiovascular risk evaluation with hs-cTn methods in some groups of patients with clinical conditions at high cardiovascular risk (such as systemic hypertension, severe obesity, diabetes mellitus, renal insufficiency, and chronic obstructive pulmonary disease). However, screening programs in the general population with hs-cTn methods for cardiovascular risk stratification require further investigation to define the optimal target populations, timing of measurement, and preventive interventions.

Serial measurements of cardiac troponin are recommended by international guidelines to diagnose myocardial infarction (MI) since 2000. However, some relevant differences exist between the three different international guidelines published between 2020 and 2021 for the management of patients with chest pain and no ST-segment elevation. In particular, there is no agreement on the cut-offs or absolute change values to diagnose non-ST-segment elevation MI (NSTEMI). Other controversial issues concern the diagnostic accuracy and cost-effectiveness of cut-off values for the most rapid algorithms (0 h/1 h or 0 h/2 h) to rule-in and rule-out NSTEMI. Finally, another important point is the possible differences between demographic and clinical characteristics of patients enrolled in multicenter trials compared to those routinely admitted to the Emergency Department in Italy. The Study Group of Cardiac Biomarkers, supported by the Italian Scientific Societies Società Italiana di Biochimica Clinica, Italian Society of the European Ligand Assay Society, and Società Italiana di Patolgia Clinica e Medicina di Laboratorio decided to revise the document previously published in 2013 about the management of patients with suspected NSTEMI, and to provide some suggestions for the use of these biomarkers in clinical practice, with a particular focus on the Italian setting.

Bakground The aim of this study was to evaluate both analytical characteristics and clinical results of a new chemiluminescent method for the measurement of cardiac troponin I (cTnI), named VITROS ® High Sensitivity Troponin I Assay, using the VITROS® 3600 automated platform. The results found with this new method were compared to those observed with hs-cTnI ARCHITECT and ECLIA hs-cTnT ELECSYS methods. Methods For evaluation of analytical performance and comparison of clinical results, plasma samples (lithium-heparin), were collected from apparently healthy subjects and patients with cardiovascular diseases. Results The hs-cTnI VITROS method showed values for limit of blank (LoB 0.33 ng/L), limit of detection (LoD, 0.91 ng/L), limit of quantifications at 20% (LoQ 20% CV, 1.82 ng/L), and 10% (LoQ 10% CV, 4,74 ng/L), which are comparable to those previously reported for other hs-cTnI methods. Moreover, the clinical results of the hs-cTnI VITROS method were found to be closely correlated to those of hs-cTnI ARCHITECT (R = 0,9883, N = 198) and ECLIA hs-cTnT Elecsys (R = 0,9704, N = 293) methods. Conclusions The hs-cTnI VITROS method shows analytical performance comparable to other cTnI and cTnT assay. The results of this study confirm that there are significant systematic differences among hs-cTnI methods. Further multicenter studies using larger reference populations are needed in order to obtain a better estimation, especially of the 99° percentile URL values categorized for sex and age of hs-cTnI and hs-cTnT methods.

Drug-induced cardiotoxicity is a major clinical problem; cardiotoxic drugs may induce both cardiac dysfunction and myocardial injury. Several recent studies reported that cardiac troponins measured with high-sensitivity methods (hs-cTn) can enable the early detection of myocardial injury related to chemotherapy or abuse of drugs that are potentially cardiotoxic. Several authors have some concerns about the standard definition of cardiotoxicity, in particular, regarding the early evaluation of chemotherapy cardiotoxicity in cancer patients. Several recent studies using the hs-cTn assay indicate that myocardial injury may precede by some months or years the diagnosis of heart failure (HF) based on the evaluation of left ventricular ejection fraction (LVEF). Accordingly, hs-cTn assay should considered to be a reliable laboratory test for the early detection of asymptomatic or subclinical cardiotoxic damage in patients undergoing cancer chemotherapy. In accordance with the Fourth Universal Definition of Myocardial Infarction and also taking into account the recent experimental and clinical evidences, the definition of drug-cardiotoxicity should be updated considering the early evaluation of myocardial injury by means of hs-cTn assay. It is conceivable that the combined use of hs-cTn assay and cardiac imaging techniques for the evaluation of cardiotoxicity will significantly increase both diagnostic sensitivity and specificity, and also better prevent chemotherapy-related left ventricular (LV) dysfunction and other adverse cardiac events. However, large randomized clinical trials are needed to evaluate the cost/benefit ratio of standardized protocols for the early detection of cardiotoxicity using hs-cTn assay in patients receiving chemotherapy for malignant diseases.

Objectives The aims of this paper were to evaluate the levels of Vitamin D (VitD) in patients with heart failure (HF), compared to a control group, to assess the effects of VitD on HF outcome and to compare VitD measurement between LIAISON immunoassay and HPLC-MS-MS methods in this population. Design and Methods We collected clinical, biochemical and outcome data from 247 patients with HF and in a subgroup of 151 patients, we measured VitD both with LIAISON and HPLC-MS-MS. Results HF patients had statistically lower 25OHD levels (45.2 ± 23.7 nmol/L vs 58.2 ± 24.0 nmol/L, P P P P = 0.02), confirmed in a multivariate adjusted analysis. Kaplan–Meier survival analyses showed that VitD insufficiency was associated with reduced survival in HF patients (log rank P = 0.017). There was a good agreement between LIAISON and HPLC-MS-MS (Cohen’s kappa coefficient 0.70), but the prevalence of VitD insufficiency was significantly higher with the former compared to the latter method (58.3%, n = 88 vs 55.6%, n = 84, P Conclusions 25OHD levels adequately measured by HPLC-MS-MS showed to be low in HF population and to be correlated with HF-related risk of death.

To the Editor: Vigorous endurance-type exercise causes cardiac troponin T (cTnT)1 elevations that often exceed the diagnostic cutoff value for acute myocardial infarction (AMI) (1). It remains to be investigated whether exercise-induced cTnT release reflects a physiological or pathological process. Our recent studies utilizing multiple protein analysis techniques allowed determination of circulating cTnT forms, and it appeared that these are different in acute vs chronic pathologies (2, 3). In sera of AMI patients, cTnT is degraded from its intact form (estimated molecular weight by SDS-PAGE; MW est, 40 kDa) to primary ( MW est, 29 kDa) and subsequent secondary ( MW est, 14–18 kDa) fragments in a time-dependent manner (2). Only …

Background The aims of this study were: (1) to calculate reliable thyroid stimulating hormone (TSH) reference intervals using laboratory databases; (2) to evaluate the relationship between TSH, sex and age values in different large Italian populations. Methods The TSH values stored in the laboratory information system of clinical laboratories of four Italian city hospitals, including 146,801 TSH measurements (with the respective age and sex data of individuals) were taken in consideration. Assuming a log-normal distribution, to log-transformed TSH values were applied the Dixon’s iterative principle in order to exclude the outliers. At the end of this iterative process 142,821 log-transformed TSH results remained. The four clinical laboratories measured serum TSH concentrations using the same TSH immunoassay method (Access TSH 3rd IS, using UniCel DxI platform). Results The TSH reference interval calculated in the present study (0.362–5.280 mIU/L) is similar to that suggested by the manufacturer for the Access TSH 3rd IS assay (0.45–5.33 mIU/L). TSH values in females were significantly higher than in males (females: mean=2.06 mIU/L; standard deviation [SD]=1.26 mIU/L; n=101,243; males: mean=1.92 mIU/L; SD=1.19 mIU/L; n=41,578; p Conclusions The results of the present multicenter study confirm that data mining techniques can be used to calculate clinically useful reference intervals for TSH. From a pathophysiological point of view, our results suggest that some Northern populations of Italy might still suffer some harmful effects on the thyroid gland due to mild to moderate iodine intake deficiency. Specific clinical trials are needed to confirm these results.

Background C-peptide and insulin are widely used in clinical practice for the diagnosis for several conditions, including hypoglycaemia and diabetes. However, the lack of method harmonization represents an important analytical limitation. Aims of this study were to evaluate new Mindray CL-2000i C-peptide and insulin methods for precision and comparability with Tosoh AIA-CL2400 and Siemens Immulite 2000 systems. Methods Mindray CL-2000i precision was evaluated by the CLSI EP15-A3 protocol and compared with the manufacturer's claimed values. A series of one hundred sixty-five specimens were used for comparing C-peptide and immunoreactive insulin (IRI) between Mindray CL-2000i, Tosoh AIA-CL2400 and Siemens Immulite 2000. Results Mindray CL-2000i repeatability results were 1.7% and 1.35% for C-peptide and 2.1% and 1.2% for IRI. Intermediate precisions were 2.6% and 1.4% for C-peptide and 4.6% and 2.3% for IRI. For C-peptide, Mindray CL-2000i performed similarly to Tosoh AIA-CL2400; for IRI a good agreement between Mindray C-2001 and Siemens Immulite 2000was found. Conclusions Mindray CL-2000i shows a low imprecision while a satisfactory for IRI between Mindray 2000i and Siemens Immulite 2000 was onbserved. Overall, results emphasize the need for standardization/harmonization efforts for both C-peptide and IRI measurement.

The international guidelines “on the Redefinition of AMI”, published in 2000 by the Joint European Society of Cardiology/American College of Cardiology (ESC/ACC) Committee, for the first time recommended that an increase of cardiac troponin I (cTnI) or T (cTnT) values over the 99 th percentile upper reference limit (99 th URL) should be considered as clinically significant, and they also specifically indicated that this thresholds value should be measured with an imprecision ≤10 coefficient of variation (CV%) (1).

According to recent international guidelines, including the 2012 Third Universal Definiton of Myocardial Infarction by the Joint ESC/ACCF/AHA/WHF Task Force, an increase in cardiac troponin (cTn) levels over the 99th percentile upper reference limit (99th URL) should be considered clinically relevant, this cut-off being measured with an imprecision ≤10 CV%. In theory 99th URL values strongly depend not only on demographic and physiological variables (i.e. criteria for considering the reference population “healthy”), but also on the analytical performance of cTn methods and mathematical algorithms used for the calculation. The aim of the present article was therefore to review the methodological and pathophysiological factors affecting the evaluation and calculation of the 99th URL for cTn assay. The critical analysis made showed that no uniform procedure is followed, and nor have experts or regulatory bodies provided uniform guidelines for researchers or cTn assays manufacturers as an aid in “their quest to define normality”. In particular, little attention has been paid to the way in which a healthy reference population is to be selected, or the criteria for calculating the 99th URL value for cTn assays, thus highlighting the need for international recommendations not only for demographic and physiological variables criteria for defining a healthy reference population, but also for calculating mathematical algorithms for establishing/calculating clinical decision values. An expert consensus group, comprising laboratory and clinical scientists, biomedical statisticians, industrial and regulatory representatives, should be responsible for drawing up these guidelines.

Background:Systematic difference between thyroid-stimulating hormone (TSH) immunoassays may produce misleading interpretation when samples of the same patients are measured with different methods. The study aims were to evaluate whether systematic differences are present among TSH immunoassays, and whether it is possible to obtain a better harmonization among TSH methods using results obtained in external quality assessment (EQA) schemes.Methods:Seven Italian clinical laboratories measured TSH in 745 serum samples of healthy subjects and patients with thyroid disorders. These samples were also re-measured by two reference laboratories of the study with the six TSH immunoassays most popular in Italy after 2 months of storage at −80 °C. Moreover, these data were compared to 53,823 TSH measurements, obtained by laboratories participant to 2012–2015 EQA annual cycles in 72 quality control samples (TSH concentrations from about 0.1 mIU/L to 18.0 mIU/L). TSH concentrations were recalibrated using a mathematical approach based on the principal component analysis (PCA).Results:Systematic differences were found between the most popular commercially available TSH immunoassays. TSH concentrations measured by the clinical laboratories were very closely correlated to those measured with the same method by reference laboratories after 2 months of storage at −80 °C. After recalibration using the PCA approach the variation of TSH values significantly decreased from a median pre-calibration value of 13.53% (10.79%–16.53%) to 9.63% (6.90%–13.21%) after recalibration.Conclusions:Our data suggest that EQA schemes are useful to improve harmonization among TSH immunoassays and also to produce some mathematical formulas, which can be used by clinicians to better compare TSH values measured with different methods.

Chronic heart failure is a major cause of morbidity and mortality, but its prognosis remains poor. Vitamin D hormone has many extra-skeletal functions including a positive impact on the cardiovascular system, and has been proposed for mortality risk evaluation in heart failure patients. The aim of the present study was to evaluate vitamin D status in heart failure patients, measured by high performance liquid chromatography coupled with mass spectrometry and to correlate serum 25 hydroxy-vitamin D (25OHD) levels with functional (peak VO2%) and mortality (Metabolic Exercise Cardiac Kidney Index) heart failure parameters. We enrolled 261 consecutive patients diagnosed with heart failure; all patients underwent a comprehensive clinical and biochemical characterization, and serum 25OHD levels were measured by high performance liquid chromatography coupled with mass spectrometry. Cardiopulmonary test parameters and Metabolic Exercise Cardiac Kidney Index of mortality risk were measured in all patients. Serum 25OHD levels ranged between 2 and 45 ng/ml (mean 17 ± 9 ng/ml); most patients (87%) showed hypovitaminosis D, and 25% showed severe vitamin D deficiency (serum 25OHD 10 ng/ml. Patients with peak VO2% 50%. There was a significant, positive correlation (r = 0.16, p = 0.008) between 25OHD levels and peak VO2%, and an inverse correlation with Metabolic Exercise Cardiac Kidney Index (r = −0.21, p

Objective: Ventricular assist device (VAD) utilization is increasing in children with heart failure (HF) unresponsive to medical therapy, allowing for bridge to transplantation. The use of circulating biomarkers is crucial for the management of adult patients with HF, but their role in pediatric setting is unknown. In this study we assessed the effects of VAD implant on plasma levels of inflammatory and cardiac biomarkers as well as of circulating micro RNAs (miRNAs) in pediatric patients with HF. Methods: Blood samples were collected from 12 HF pediatric patients [73.91±27.94 (mean±SD) months, 6 males, 19±3.8 LVEF%, Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles 1/2] before and at 4 hrs, 1, 3, 7, 14 and 30 days after VAD implant. Indications for support was idiopathic dilated (9 patients), non compaction (2 patients) and hypertrophic cardiomyopathy (1 patient). Inflammatory and cardiac biomarkers (Figure 1A) were measured in frozen plasma through the use of immunoassay tests. The circulating miRNAs were extracted from serum samples and miRNA profile was determined by NGS. and validated by real-time PCR. Results: Inflammatory and cardiac biomarker levels during time-course were reported in Figure 1A. Cytokines increased significantly up to 4 hrs after VAD implant, while cardiac biomarkers up to 1 day. Only NT-proBNP decreased significantly up to 1 month of VAD implant compared to pre-VAD values. After sequencing, a total of 169 miRNAs were detected in serum samples. Among them, 13 miRNAs were simultaneously modulated at 1 month after VAD implant compared to pre-VAD levels, i.e. 9 miRNAs decrease and 4 increase (Figure 1B). Real-time PCR validation confirmed a reduction for miR-409-3p and miR-432-5p. Finally, significant correlations with bio-humoral markers were observed for these miRNAs (Figure 1 C). Conclusions: VAD implant induced modifications in circulating levels of cytokine, cardiac biomarkers and miRNAs. NT-proBNP levels and miRNAs significantly decreased after 1 month compared to the values pre-VAD, suggesting the involvement of these biomarkers in molecular mechanisms triggered by VAD implant in children.

Aim of the study Recently, Beckman Coulter Diagnostics set up a new TSH immunoassay for the automated DxI platform. The aim of this study was to evaluate and compare the analytical performance and clinical results of this method with those of previous method. Material and methods A multicenter study (named TSH ELAS Study) was organized using 593 serum samples, collected from healthy subjects and patients with thyroid disorders, and 13 control samples, circulated in an External Quality Assessment (EQA) scheme. Results The values of LoB and LoD, and LoQ at 20% CV were 0.0004 mIU/L, 0.001 mIU/L and 0.0023 mIU/L, respectively. Moreover, TSH concentrations > 0.01 mIU/L actually show imprecision values lower than 5% CV. This new TSH assay showed a systematic underestimation (on average of 6.25%) compared to old method, which is mainly due to larger differences between methods for samples with low TSH concentrations, related to the better analytical sensitivity of new compared to old method. In a reference population, including 279 apparently healthy adult subjects, Caucasian volunteers (mean age 43.6 years, age 20–63 years, 138 women and 141 males) the distribution of TSH concentrations was: mean (CI 95%) 1.694 mIU/L (1.588–1.779), median 1.495 mIU/L (1.412–1.588 mIU/L), 97.5th percentile 3.707 mIU/L. Conclusions The new TSH immunoassay for DxI platform shows some relevant improvements compared to the previous one: use of the most recent WHO 3rd IRP 81/563 standard and monoclonal antibodies (instead of polyclonal antibodies of the old method), and better analytical sensitivities and reproducibility.

Expression of endothelin (ET)-1 is increased in endothelial cells exposed to angiotensin II (Ang II), leading to endothelial dysfunction and cardiovascular disorders. Since von Willebrand Factor (vWF) blockade improves endothelial function in coronary patients, we hypothesized that targeting endothelial vWF with short interference RNA (siRNA) prevents Ang II-induced ET-1 upregulation. Nearly 65 ± 2% silencing of vWF in porcine aortic endothelial cells (PAOECs) was achieved with vWF-specific siRNA without affecting cell viability and growth. While showing ET-1 similar to wild type cells at rest, vWF-silenced cells did not present ET-1 upregulation during exposure to Ang II (100 nM/24 h), preserving levels of endothelial nitric oxide synthase activity similar to wild type. vWF silencing prevented AngII-induced increase in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity and superoxide anion (O2−) levels, known triggers of ET-1 expression. Moreover, no increase in O2− or ET-1 levels was found in silenced cells treated with AngII or NOX-agonist phorbol ester (PMA 5 nM/48 h). Finally, vWF was required for overexpression of NOX4 and NOX2 in response to AngII and PMA. In conclusion, endothelial vWF knockdown prevented Ang II-induced ET-1 upregulation through attenuation of NOX-mediated O2− production. Our findings reveal a new role of vWF in preventing of Ang II-induced endothelial dysfunction.

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 P 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.

Background The aim of this study is to evaluate whether it is possible to reduce the between-methods variability of troponin I (cTnI) immunoassays using mathematical algorithms calculated from the results of both patients' samples and quality control materials distributed in an external quality assessment (EQA) scheme. Methods We collected 122 heparinized plasma samples of patients admitted to the emergency department with thoracic pain or supraventricular tachyarrhythmia. Moreover, we also analyzed 20 control samples distributed in an EQA and 26 plasma pools prepared from healthy subjects and patients with myocardial infarction. We evaluated 4 different methods for cTnI assay: STAT Architect High Sensitive TnI (Abbott Diagnostics), ADVIA Centaur Troponin I Ultra (Siemens Healthcare Diagnostics), ST AIA-Pack cTnI Third Generation (Tosoh Bioscience), and Access AccuTnI + 3 (Beckman Coulter Diagnostics). Results Systematic differences between cTnI methods were observed. However, correlation coefficients (R from 0.976 to 0.990) between the log-transformed cTnI values measured in all 168 samples were significantly better (p = 0.0037) than those obtained considering only the 122 patients' samples. cTnI values measured in EQA and pool samples were included within the 95% prediction intervals of linear regressions calculated with those of patients' samples. After the recalibration of cTnI values based on the robust principal component analysis approach the between-methods variability decreased significantly (about 40% around the cut off values). Conclusions Our pilot study suggests that EQA schemes for cTnI immunoassay methods, based on both quality control samples with tested commutability and robust statistical analyses, are able to evaluate between-methods variability as well as allow a reliable recalibration and harmonization of results.

Several studies indicated that B-type natriuretic peptide (BNP) assay is able to detect patients even in the early phases of heart failure (HF), when the myocardial remodeling process may be still reversible. BNP assay may assist the physician to initiate appropriate and prompt pharmacological treatments. However, clinical relevance and result interpretation of BNP assay for the guide of therapy or in particular clinical conditions, such as renal failure or treatment with inhibitors of enzymes degrading BNP in HF patients, are still debated. The aim of this article is to discuss some still controversial issues concerning the clinical use of measurement of cardiac natriuretic peptides, and also to provide a general overview and some perspectives related to pathophysiological mechanisms of HF.

The aim of this review article is to give an update on the state of the art of the immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides. Using chromatographic procedures, several studies reported an increasing number of circulating peptides related to BNP in human plasma of patients with heart failure. These peptides may have reduced or even no biological activity. Furthermore, other studies have suggested that, using immunoassays that are considered specific for BNP, the precursor of the peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of patients with heart failure. Because BNP immunoassay methods show large (up to 50%) systematic differences in values, the use of identical decision values for all immunoassay methods, as suggested by the most recent international guidelines, seems unreasonable. Since proBNP significantly cross-reacts with all commercial immunoassay methods considered specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians should take into account that there are large systematic differences between methods when they compare results from different laboratories that use different BNP immunoassays. On the other hand, clinical laboratories should take part in external quality assessment (EQA) programs to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors believe that the development of more specific methods for the active peptide, BNP1-32, should reduce the systematic differences between methods and result in better harmonization of results.

The study aims are to evaluate the analytical performance and the clinical results of the chemiluminescent Access AccuTnI+3 immunoassay for the determination of cardiac troponin I (cTnI) with DxI 800 and Access2 platforms and to compare the clinical results obtained with this method with those of three cTnI immunoassays, recently introduced in the European market. The limits of blank (LoB), detection (LoD), and quantitation (LoQ) at 20% CV and 10% CV were 4.5 ng/L and 10.9 ng/L, 17.1 and 30.4 ng/L, respectively. The results of STAT Architect high Sensitive TnI (Abbott Diagnostics), ADVIA Centaur Troponin I Ultra (Siemens Healthcare Diagnostics), ST AIA-Pack cTnI third generation (Tosoh Bioscience), and Access AccuTnI+3 (Beckman Coulter Diagnostics) showed very close correlations (R ranging from 0.901 to 0.994) in 122 samples of patients admitted to the emergency department. However, on average there was a difference up to 2.4-fold between the method measuring the highest (ADVIA method) and lowest cTnI values (AccuTnI+3 method). The consensus mean values between methods ranged from 6.2% to 29.6% in 18 quality control samples distributed in an external quality control study (cTnI concentrations ranging from 29.3 ng/L to 1557.5 ng/L). In conclusion, the results of our analytical evaluation concerning the AccuTnI+3 method, using the DxI platform, are well in agreement with those suggested by the manufacturer as well as those reported by some recent studies using the Access2 platform. Our results confirm that the AccuTnI+3 method for the Access2 and DxI 800 platforms is a clinically usable method for cTnI measurement.

*Corresponding author: Prof. Aldo Clerico, MD, Department of Laboratory Medicine, Fondazione CNR-Regione Toscana G. Monasterio, Scuola Superiore Sant ’ Anna, Via Moruzzi 1, 56126 Pisa, Italy, Phone: + 39 0585 493569, Fax: + 39 0585 493601, E-mail: clerico@ftgm.it ; and Scuola Superiore Sant ’ Anna, Pisa, Italy Concetta Prontera, Michele Emdin and Claudio Passino: Fondazione CNR-Regione Toscana G. Monasterio, Pisa, Italy Silvia Masotti and Maria Franzini: Scuola Superiore Sant ’ Anna, Pisa, Italy Gian Carlo Zucchelli: QualiMedLab Spin-Off dell ’ Istituto di Fisiologia Clinica del CNR, Pisa, Italy Letter to the Editor

The lack of interchangeable laboratory results and consensus in current practices has underpinned greater attention to standardization and harmonization projects. In the area of method standardization and harmonization, there is considerable debate about how best to achieve comparability of measurement for immunoassays, and in particular heterogeneous proteins. The term standardization should be used only when comparable results among measurement procedures are based on calibration traceability to the International System of Units (SI unit) using a reference measurement procedure (RMP). Recently, it has been promoted the harmonization of methods for many immunoassays, and in particular for thyreotropin (TSH), as accepted RMPs are not available. In a recent paper published in this journal, a group of well-recognized authors used a complex statistical approach in order to reduce variability between the results observed with the 14 TSH immunoassay methods tested in their study. Here we provide data demonstrating that data from an external quality assessment (EQA) study allow similar results to those obtained using the reported statistical approach.

The finding of elevated cardiac troponin levels (i.e. values above the99thpercentilevalueofthereferencepopulation)notrelatedtoischemicmyocardial injury in patients admitted to the emergency department(ED) with suspected acute myocardial infarction (AMI), represents arelevant clinical problem, increasingly observed in the last few years,following the implementation of cardiac troponin (cTnI, cTnT) measure-ment with high-sensitivity immunoassays [1]. Indeed, the majority ofpatients (up to 70%) admitted to the ED with more than one elevatedtroponin level may actually have myocardial injury unrelated to acutecoronary syndrome (ACS), especially when they have an age of morethan 70 years, heart failure, and/or other comorbidities [2,3]. In suchpatients, the incidence of “falsepositive”cases,i.e.the findingof troponinelevations in the absence of clinically documented myocardial injury, isactually unknown. Clinical observation however suggests that the per-centage of “false positive” troponin elevations is extremely low.Inapaperrecentlypublishedinthejournal[4],aclinicalcaseofapa-tient presenting to the ED with suspicion of AMI and non-diagnosticECG that shows a false positive cTnI result due to the presence in theblood sample of an analytical interference caused by heterophilic anti-bodies,hasbeenpublished.Theauthorssuggesttheadoptionofanalgo-rithm that allows the prompt detection of the supposed false-positiveresult. The described protocol considers the systematic measurementof CK-MB reflex testing in all troponin-positive samples as a reliabletool for the identification of biological and analytical interference. Thisreflextestingisbasedontheuseofawellknownbutoutdatedbiomark-erwhichlackssensitivityandspecificityforthedetectionofmyocardialinjury when compared with cardiac troponin. In addition the Authorsseemtoignorecurrentinternationalguidelines[5],whichbasethediag-nosis of myocardial infarction, along with the documentation of objec-tive evidence of myocardial ischemia, on the correct interpretation ofserialcardiactroponintesting.Infacttheanalysisofthereleasekineticsof troponin may permit the distinction between myocardial damagecaused by myocardial ischemia from myocardial injury caused byother factors and, possibly, from “false positive” troponin elevations[5,6]. According to these criteria, the detection of a rise and/or fall pat-tern of troponin with at least one value above the 99th percentileupper reference limit, is needed to make the diagnosis. It is well know,instead, that theinterference ofaheterophilicantibodytypically causesa constant (chronic) increase in troponin values, which cannot beconfused with the typical kinetic of the biomarker in AMI patients.Therefore, the interference by heterophilic antibodies should be differ-entiated from the huge number of clinical conditions which can causea chronic increase in troponin levels [5].Reflex testing is usually per-formed when the result of a first screening test is positive, in order toimprovethespecificity,althoughatthecostoflowersensitivity.Thisdi-agnostic strategy, therefore, should be adopted in clinical laboratorypractice to improve specificity employing a second text more specific(but more expensive and time consuming) than the screening text.Inthe case of the proposed reflex testing [4], the cardiac specificity of thesecond test (i.e. CK-MB) is significantly lower than the specificity ofthe screening test (i.e. cardiac troponin) and significantly less sensitivefor cardiac damage. As a consequence, the potential clinical advantageof using a very sensitive and cardio-specific screening test, such as thecardiactroponins, appearsto be, intheproposed “reflextesting” strate-gy, completely lost. A huge number of clinical studies have definitivelydemonstrated that cardiac troponins (particularly when assayed withhigh-sensitivity methods) represent a more cardiac-specific and sensi-tive biomarker than CK-MB in cardiovascular risk stratification, both inthe general population as well as in patients with cardiac disease [1,7]confirmingthatthemeasurementof CK-MBisnowobsolete.Moreover,considering that the incidence of heterophilic antibodies in the generalpopulationvariesgreatlyindifferentstudies(from0.17to40%)[8,9]thereflextestingproposed,ifappliedsystematicallyinallpatientsadmittedto the ED with increased troponin values, may allow the detection of

Heart failure is a major global health problem affecting 23 million people worldwide. As more cardiac patients survive and live longer with this progressive disease, heart failure is a condition for which the prevalence will grow. Based solely on clinical presentation, heart failure can be difficult to diagnose since its presentation is complex, with signs and symptoms that are nonspecific and may not always be present. B-type natriuretic peptide (BNP)7 and N-terminal proBNP (NT-proBNP) are well established, clinically validated biomarkers that have been shown to improve the diagnostic accuracy for heart failure and provide prognostic information for risk stratification. The widespread clinical use of these biomarkers for more than a decade is reflected by their incorporation into national and international medical guidelines for heart failure, at the highest classification for recommendation. BNP is a cardiac hormone secreted by cardiomyocytes into the circulation in response to states of volume expansion and pressure overload, as is the case in heart failure. BNP's diuretic, natriuretic, and vasodilatory actions, and its protective effects on endothelial function and vascular remodeling, act to relieve the adverse consequences of heart failure. During the synthesis and processing of BNP, its 108 amino acid biologically inactive precursor, proBNP, is proteolytically cleaved to form the 32 amino acid peptide BNP and the 76 amino acid peptide NT-proBNP. While BNP is physiologically active, NT-proBNP is biologically inert. Due to its secretion at a 1:1 ratio to BNP and its longer half-life (90–120 min vs 20 min for BNP), the measurement of NT-proBNP has proven to have an essentially equivalent clinical performance to BNP as a biomarker for heart failure. In recent years, the simplistic model for the processing of BNPs has undergone a dramatic shift, with a better understanding of the complexity of their posttranslational modification and secretion. ProBNP is …

Although the perioperative event rate has declined over the past 30 years, as a consequence of the developments in anesthesiology and surgical techniques, perioperative cardiovascular complications are still a significant clinical problem. At the end of the last century, a pooled analysis of several large studies found a 30-day incidence of cardiac events of 2.5% in unselected patients aged >40 years. The identification of myocardial injury after non-cardiac surgery is a problematic and tough challenge, since up to 50% of cardiac deaths actually occur in patients with no history of overt heart disease. Recently, among novel sensitive and specific cardiovascular risk markers, the European Society of Cardiology and European Society of Anesthesiology guidelines for preoperative cardiac risk assessment have recommended that preoperative brain natriuretic peptide (BNP) or N-terminal fragment of proBNP (NT-proBNP) measurement should be considered in high-risk patients undergoing non-cardiac surgery. However, several recent studies and meta-analyses, published in the last 5 years, strongly support the use of both assays of cardiac B-type natriuretic peptides and troponins, for risk stratification in patients undergoing non-cardiac surgery, in order to improve operative and postoperative outcome. Indeed, an increase in specific cardiac biomarkers, as it is the case for natriuretic peptides and troponins, always indicates that the heart is under a stress condition or even actually injured, respectively. In conclusion, the authors suggest that future guidelines on cardiovascular risk evaluation in patients undergoing major surgical procedures should take into account the following evidence.

OBJECTIVE: The aim of this study was to evaluate the diagnostic and prognostic accuracy of brain natriuretic peptide assay in neonates and children undergoing surgery for congenital heart disease. DESIGN: Prospective, observational study. SETTING: Single center. PATIENTS: We enrolled 336 consecutive children (median age, 6 mo [range, 0-37 mo]) undergoing cardiac surgery (87 neonates; age, 7 d [5-12]; median, 25th-75th percentile; 24 infants and children; age, 11 mo [4-60]) and 436 healthy controls. INTERVENTIONS: Brain natriuretic peptide was measured preoperatively, on every postoperative day in the ICU, and at discharge. Intubation time was the primary outcome. MEASUREMENTS AND MAIN RESULTS: Preoperative brain natriuretic peptide values in patients with congenital heart disease were higher than those in controls (p < 0.01). Brain natriuretic peptide had a good diagnostic accuracy in discriminating between patients with congenital heart disease and healthy controls with an area under the curve = 0.918 for neonates and area under the curve = 0.894 for older children. The best cutoff values, calculated by receiver operating characteristic analysis, were different for the two age subgroups with cutoff values of 363.5 ng/L for neonates and 23.5 ng/L for older children. At 24 hours after surgery, although brain natriuretic peptide decreased in neonates (baseline 2723 vs 1290 ng/L, p < 0.001), it increased in children (60 vs 365 ng/L at 24 hours, p < 0.001). Multivariable analysis identified the preoperative level of brain natriuretic peptide in infant/children and the difference in brain natriuretic peptide value (baseline 24 hours) in neonates, as independent predictors of intubation time. Furthermore, body surface area, Aristotle score, and cardiopulmonary bypass time had an independent significant effect on the endpoint in either group. CONCLUSIONS: Baseline cardiac endocrine function and its response to surgical stress are dependent on age in neonates and children, undergoing cardiac surgery for congenital heart disease. Brain natriuretic peptide shows a good diagnostic and prognostic accuracy in this setting, with different features in either neonates or infants/children subsets.

Background Recent studies suggested that there are marked systematic differences among BNP immunoassays. In this study we compared the BNP data and clinical results obtained with different immunoassays, including a new method (ST-AIA-PACK, TOSOH Corporation). Methods BNP was measured on plasma-EDTA samples of healthy subjects (HS, n = 126) and patients with heart failure (HF, n = 31 NYHA I, II; n = 46 NYHA III, IV) using the ST-AIA-PACK and the Triage Biosite (Beckman Coulter) methods. Control samples distributed in the CardioOrmoCheck external quality assessment were also measured with TOSOH and the most used BNP immunoassays in Italy. Results TOSOH method showed a good correlation (R = 0.976; n = 327) but a mean bias (− 46.9%) compared to Triage Biosite. On the base of the results obtained in 10 samples of the CardioOrmoCheck study, TOSOH method showed a strict agreement with ADVIA Centaur, while it underestimated BNP in comparison with Triage (− 52.5%) and ARCHITECT methods (− 39.4%). The agreement of ST-AIA-PACK and Triage Biosite methods for classification of HF patients was tested using 100 ng/L of BNP; the positive agreement between methods was 65%, overall agreement was 73%. Conclusions Our results confirm that there are marked differences in measured values among commercial methods for BNP assay.

The purpose of this document is to develop recommendations on the use of the latest generation of cardiac troponins in emergency room settings for the diagnosis of myocardial infarction in patients with suspected acute coronary syndrome (ACS) without persistent ST-segment elevation (NSTE-ACS). The main points which have been addressed reaching a consensus are represented by: Suitability and appropriateness of the terminology. Appropriateness of the request. Confirmation of the diagnosis of myocardial infarction (rule-in). Exclusion of the diagnosis of myocardial infarction (rule-out).Each point has been analyzed by taking into account the evidence presented in medical publications. Recommendations were developed using the criteria adopted by the European Society of Cardiology and the American Heart Association/American College of Cardiology (www.escardio.org/guidelines). Each point of the recommendation was submitted for validation to an external audit by a Group of Experts (named above).

The high prevalence of obesity in children may increase the magnitude of lifetime risk of cardiovascular disease (CD). At present, explicit data for recommending biomarkers as routine pre-clinical markers of CD in children are lacking. C-type natriuretic peptide (CNP) is assuming increasing importance in CD; in adults with heart failure, its plasma levels are related to clinical and functional disease severity. We have previously reported five different reference intervals for blood CNP as a function of age in healthy children; however, data on plasma CNP levels in obese children are still lacking. Aim of this study was to assess CNP levels in obese adolescents and verify whether they differ from healthy subjects. Plasma CNP was measured in 29 obese adolescents (age: 11.8 ± 0.4 years; BMI: 29.8 ± 0.82) by radioimmunoassay and compared with the reference values of healthy subjects. BNP was also measured. Both plasma CNP and BNP levels were significantly lower in the obese adolescents compared to the appropriate reference values (CNP: 3.4 ± 0.2 vs 13.6 ± 2.3 pg/ml, p