Troponin T Concentrations Research Articles

Angiographic coronary artery disease and high-sensitivity troponin-T in a native Pakistani cohort presenting with chronic chest pain.

To determine the relationship between troponin-T levels and atheroma burden in Pakistanis presenting to an ambulatory centre with chest pain. A prospective case-control study of 400 patients selected for presence/absence of angiographic disease referred between 2001 and 2003. A comprehensive cardiovascular disease (CVD) risk factor profile was assessed including demographics, environmental and biochemical risk factors including insulin resistance and troponin-T levels. Coronary atheroma burden was quantified by Gensini score. Clinically significant elevated troponin-T levels (> 30 pmol/l) were found in 40 patients (10%) with equal numbers in groups selected with or without angiographic disease. Troponin-T elevation (> 13 pmol/l) was present in 59 vs. 47 patients (30% vs. 24%; p = 0.04). Troponin-T levels did not correlate with any measured demographical, environmental, drug therapy or biochemical risk factor. No difference was found in concentrations of lipids, apolipoproteins, insulin resistance, C-reactive protein or sialic acid in cohorts stratified by troponin-T concentrations. In univariate analysis comparing patients with high (> 30 pmol/l) and low troponin-T levels (< 13 pmol/l) higher plasma total protein (91 g/l vs. 85 g/l; p = 0.01), increased immunoglobulin levels (41 g/l vs. 36 g/l; p = 0.02) and prevalence of hyperparathyroidism (40% vs. 21%; p = 0.04) were associated with higher troponin-T concentrations. This study shows that measurement of troponin-T is not an alternative to imaging in an Indian asian population, but that it does identify a separate potentially high-risk population that would not be identified by the use of imaging alone which is potentially at higher risk of CVD events.

Improved Rate Control Reduces Cardiac Troponin T Levels in Permanent Atrial Fibrillation

Detectable levels of troponins are often found in serum of patients with atrial fibrillation (AF), and recent reports suggest that Tn concentrations are independently related to patient prognosis. We hypothesized that treatment with common rate-reducing drugs might lower the levels of cardiac troponin T (TnT) in patients with permanent AF. We also wanted to investigate whether the different drugs would impact the Tn levels differently. Sixty patients were included (mean age 71 ± 9 years, 18 women) in this randomized crossover study. All patients had stable, permanent AF without ischemic heart disease or congestive heart failure. Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered once daily for 3 weeks, in a randomized sequence. At baseline and on the last day of each treatment period, TnT concentrations were measured at rest and after a maximal exercise test. TnT was detectable in all patients. In 22% of the patients, TnT concentrations were above the threshold normally used for diagnosing myocardial infarction. All drugs reduced the levels of TnT significantly compared with baseline (P < 0.001 for all), but there were no significant differences between the treatments. Levels of TnT increased significantly in response to exercise testing (P < 0.001 for all). Elevated TnT was demonstrated in a large proportion of stable patients with permanent AF without ischemic heart disease. A moderate reduction of heart rate by the study drugs was associated with a significant reduction in levels of TnT.

Troponin Elevation in Severe Sepsis and Septic Shock

Serum troponin concentrations predict mortality in almost every clinical setting they have been examined, including sepsis. However, the causes for troponin elevations in sepsis are poorly understood. We hypothesized that detailed investigation of myocardial dysfunction by echocardiography can provide insight into the possible causes of troponin elevation and its association with mortality in sepsis. Prospective, analytic cohort study. Tertiary academic institute. A cohort of ICU patients with severe sepsis or septic shock. Advanced echocardiography using global strain, strain-rate imaging and 3D left and right ventricular volume analyses in addition to the standard echocardiography, and concomitant high-sensitivity troponin-T measurement in patients with severe sepsis or septic shock. Two hundred twenty-five echocardiograms and concomitant high-sensitivity troponin-T measurements were performed in a cohort of 106 patients within the first days of severe sepsis or septic shock (2.1 ± 1.4 measurements/patient). Combining echocardiographic and clinical variables, left ventricular diastolic dysfunction defined as increased mitral E-to-strain-rate e'-wave ratio, right ventricular dilatation (increased right ventricular end-systolic volume index), high Acute Physiology and Chronic Health Evaluation-II score, and low glomerular filtration rate best correlated with elevated log-transformed concomitant high-sensitivity troponin-T concentrations (mixed linear model: t = 3.8, 3.3, 2.8, and -2.1 and p = 0.001, 0.0002, 0.006, and 0.007, respectively). Left ventricular systolic dysfunction determined by reduced strain-rate s'-wave or low ejection fraction did not significantly correlate with log(concomitant high-sensitivity troponin-T). Forty-one patients (39%) died in-hospital. Right ventricular end-systolic volume index and left ventricular strain-rate e'-wave predicted in-hospital mortality, independent of Acute Physiology and Chronic Health Evaluation-II score (logistic regression: Wald = 8.4, 6.6, and 9.8 and p = 0.004, 0.010, and 0.001, respectively). Concomitant high-sensitivity troponin-T predicted mortality in univariate analysis (Wald = 8.4; p = 0.004), but not when combined with right ventricular end-systolic volume index and strain-rate e'-wave in the multivariate analysis (Wald = 2.3, 4.6, and 6.2 and p = 0.13, 0.032, and 0.012, respectively). Left ventricular diastolic dysfunction and right ventricular dilatation are the echocardiographic variables correlating best with concomitant high-sensitivity troponin-T concentrations. Left ventricular diastolic and right ventricular systolic dysfunction seem to explain the association of troponin with mortality in severe sepsis and septic shock.

Electrochemical evaluation of troponin T imprinted polymer receptor

The selective detection and quantification of macromolecular targets is a fundamental biological mechanism in nature. Molecularly imprinted polymers (MIPs) have been identified as one of the most promising synthetic alternatives to bioreceptors. However, expanding this methodology towards selective recognition of bulky templates such as proteins appears to be extremely challenging due to problems associated with removal of the template from the polymeric network. In this study, polymer imprinted with troponin T (TnT) was assessed using electrochemical methods and the influence of various extraction methods, including conventional immersion extraction, thermal annealing and ultrasonic-assisted extraction, on the binding characteristics of the troponin-to-imprinted polymer receptor was elucidated. Cyclic voltammetric deposition of o-phenylenediamine (o-PD) film in the presence of TnT as a template was performed in acetate buffer (0.5M, pH 5.2) on a gold substrate. Solvent extraction of the target molecule was optimised and followed by subsequent washing with water. The electrochemistry of a ferro/ferricyanide probe was used to characterise the TnT MIP receptor film. The incubation of the TnT MIP receptor-modified electrode with respect to TnT concentration resulted in a suppression of the ferro/ferricyanide redox current. The dissociation constant (KD) was calculated using a two-site model of template affinity for the TnT MIP receptor. The synthetic TnT MIP receptor had high affinity for TnT with a KD of 2.3×10−13M.

Rapid and Sensitive Detection of Nano-fluidically Trapped Protein Biomarkers

ABSTRACTIn this work, we demonstrate the label-free and ultrasensitive detection of troponin-T, cardiac biomarker using nanoporous membrane integrated on a microelectrode sensor platform. The nanoporous membrane allows for spatial confinement of the protein molecules. Antigen interaction with thiol immobilized antibody perturbs the electrical double layer. Charge perturbations are recorded as impedance change at low frequency using the principle of electrochemical impedance spectroscopy (EIS). The measured impedance change is used to quantitatively determine the concentration of troponin-T in tested sample. We have shown that sensitivity of sensor for troponin-T to be 1pg/mL. The accuracy and reliability of this sensor was tested by comparing the experimental troponin-T concentration values with a commercially available electrochemiluminescence assay measured with Roche Elecsys analyzer. Using this technique we were successful in detecting protein biomarkers in whole blood, human serum, and ionic buffers. This technology provides a robust analytical platform for rapid and sensitive detection of protein biomarkers, thus establishing this technology as an ideal candidate for biomarker screening in clinical settings.

Ultra-sensitive electrical immunoassay biosensors using nanotextured zinc oxide thin films on printed circuit board platforms

This study demonstrates the development of nanotextured zinc oxide (ZnO) thin films sputter deposited on printed circuit boards (PCB) to enhance the capability in detecting low concentrations of the protein troponin-T. The presence of this particular biomarker in the bloodstream is a direct indicator of current and/or future risk of various forms of cardiovascular diseases. Electrical transduction through impedance spectroscopy was used to detect troponin-T functionalized immunoassays on nanotextured ZnO surfaces. Calibration of the immunoassay was performed by measuring the impedance changes resulting from the binding of increasing concentrations of troponin-T to the immobilized antibodies on the ZnO surface in (i) phosphate buffered saline (PBS) and (ii) human serum. The limit of detection achieved using this platform was 10fg/mL and 100fg/mL in PBS and human serum, respectively. Enhanced detection of troponin-T was found to correlate to the oxygen vacancies in the ZnO thin film. PCB was chosen as the substrate for ease of integration with microelectronic device manufacturing.

Myocardial Protection by Glucose-Insulin-Potassium in Acute Coronary Syndrome Patients Undergoing Urgent Multivessel Off-Pump Coronary Artery Bypass Surgery

Background The aim of this randomized and controlled trial was to investigate the effect of a glucose–insulin–potassium (GIK) solution on myocardial protection in acute coronary syndrome (ACS) patients undergoing urgent multivessel off-pump coronary artery bypass (OPCAB) surgery. Methods Sixty-six patients were randomly allocated either to receive 0.3 ml kg−1 h−2 GIK solution (potassium 80 mEq and regular insulin 325 IU in 500 ml of 50% glucose) or equivalent volume of normal saline (control) upon anaesthetic induction until 6 h after reperfusion. The primary endpoints were to compare the concentrations of creatine kinase-MB (CK-MB) and troponin-T between the groups after reperfusion. The secondary endpoints were to compare the incidences of postoperative troponin-T >0.8 ng ml−1 and myocardial infarction (MI) between the groups. Results Highest CK-MB [8.7 (4.4) vs 13.1 (7.9) ng ml−1, P=0.006] and troponin-T [0.20 (0.13–0.49) vs 0.48 (0.18–0.91) ng ml−1, P 0.8 ng ml−1 after reperfusion compared with the control group (3 vs 11, P=0.033). The incidence of postoperative MI was similar between the groups. Conclusions GIK administration in ACS patients undergoing urgent multivessel OPCAB significantly attenuated the degree of ensuing myocardial injury without complications related to glycaemic control. Clinical Trial Registry. URL: http://clinicaltrials.gov/ct2/show/NCT01384656?term=GIK+AND+OPCAB&rank=1 . Unique identification number NCT01384656.

An ultrasensitive molecularly-imprinted human cardiac troponin sensor

Cardiac troponin T (TnT) is a highly sensitive cardiac biomarker for myocardial infarction. In this study, the fabrication and characterisation of a novel sensor for human TnT based on a molecularly-imprinted electrosynthesised polymer is reported. A TnT sensitive layer was prepared by electropolymerisation of o-phenylenediamine (o-PD) on a gold electrode in the presence of TnT as a template. To develop the molecularly imprinted polymer (MIP), the template molecules were removed from the modified electrode surface by washing with alkaline ethanol. Electrochemical methods were used to monitor the processes of electropolymerisation, template removal and binding. The imprinted layer was characterised by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). The incubation of the MIP-modified electrode with respect to TnT concentration resulted in a suppression of the ferro/ferricyanide redox process. Experimental conditions were optimised and a linear relationship was observed between the peak current of [Fe(CN)6]3−/[Fe(CN)6]4− and the concentration of TnT in buffer over the range 0.009–0.8ng/mL, with a detection limit of 9pg/mL. The TnT MIP sensor was shown to have a high affinity to TnT in comparison with non-imprinted polymer (NIP) electrodes in both buffer and blood serum.

Troponin T, N-Terminal Pro–B-Type Natriuretic Peptide, and Incidence of Stroke

Background and Purpose— Increased levels of plasma troponins and natriuretic peptides are associated with increased risk of cardiovascular disease, but only limited information exists on these biomarkers and stroke occurrence. In a prospective epidemiological study, we tested the hypothesis that high-sensitivity troponin T (TnT) and N-terminal pro–B-type natriuretic peptide (NT-proBNP) are associated positively with incidence of stroke. Methods— The Atherosclerosis Risk in Communities (ARIC) Study measured plasma TnT and NT-proBNP in 10 902 men or women initially free of stroke and followed them for a mean of 11.3 years for stroke occurrence (n=507). Results— Both biomarkers were associated positively with total stroke, nonlacunar ischemic, and especially cardioembolic stroke, but not with lacunar or hemorrhagic stroke. For example, after adjustment for prevalent risk factors and cardiac diseases, the hazard ratios (95% CIs) for jointly high values of TnT and NT-proBNP (versus neither biomarker high) were 2.70 (1.92–3.79) for total stroke and 6.26 (3.40–11.5) for cardioembolic stroke. Associations with stroke appeared somewhat stronger for NT-proBNP than TnT. Strikingly, ≈58% of cardioembolic strokes occurred in the highest quintile of prestroke NT-proBNP, and 32% of cardioembolic strokes occurred in participants who had both NT-proBNP in the highest quintile and were known by ARIC to have atrial fibrillation sometime before their cardioembolic stroke occurrence. Conclusions— In the general population, elevated plasma TnT and NT-proBNP concentrations are associated with increased risk of cardioembolic and other nonlacunar ischemic strokes.

Abstract 79: Troponin T, NT-proBNP, and Incidence of Stroke: The Atherosclerosis Risk in Communities (ARIC) Study

Increased levels of plasma troponins and natriuretic peptides in the general population are associated with increased future risk of cardiovascular disease, but only limited information exists on these biomarkers and stroke occurrence. In a prospective epidemiological study, the Atherosclerosis Risk in Communities (ARIC) Study, we tested the hypothesis that high-sensitivity troponin T (TnT) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are associated positively with incidence of stroke. We measured plasma high-sensitivity TnT and NT-proBNP in 10,902 men or women initially free of stroke and followed them for a mean of 11.3 years for stroke occurrence (n=507). Analyses were performed using proportional hazards modeling. Both biomarkers were associated positively with total stroke, nonlacunar ischemic, and especially, cardioembolic stroke, but not with lacunar or hemorrhagic stroke. After adjustment for other stroke risk factors, the hazard ratio (95% CI) per one SD greater increment of natural log-transformed TnT was 1.23 (1.13, 1.35) for total stroke, 1.27 (1.15, 1.40) for total ischemic stroke, and 1.36 (1.14, 1.62) for cardioembolic stroke. Likewise, the hazard ratio per one SD greater natural log-transformed NT-proBNP, was 1.37 (1.26, 1.49) for total stroke, 1.39 (1.27, 1.53) for total ischemic stroke, and 1.95 (1.67, 2.28) for cardioembolic stroke. The hazard ratios for jointly high values of TnT (≥0.013 ug/L) and NT-proBNP (≥155.2 pg/mL), versus neither biomarker high, were 2.70 (1.92, 3.79) for total stroke and 6.26 (3.40, 11.5) for cardioembolic stroke, and somewhat stronger for NT-proBNP than TnT. Strikingly, approximately 58% of cardioembolic strokes occurred in the highest quintile of pre-stroke NT-proBNP (versus 3% occurring in the lowest quintile), and 32% of cardioembolic strokes occurred in participants who had both NT-proBNP in the highest quintile and were known by ARIC to have atrial fibrillation sometime before their cardioembolic stroke occurrence. In conclusion, in the general population, elevated plasma TnT and NT-proBNP concentrations are associated with increased risk of cardioembolic and other nonlacunar ischemic strokes.

Myocardial protection by glucose–insulin–potassium in acute coronary syndrome patients undergoing urgent multivessel off-pump coronary artery bypass surgery

The aim of this randomized and controlled trial was to investigate the effect of a glucose-insulin-potassium (GIK) solution on myocardial protection in acute coronary syndrome (ACS) patients undergoing urgent multivessel off-pump coronary artery bypass (OPCAB) surgery. Sixty-six patients were randomly allocated either to receive 0.3 ml kg(-1) h(-2) GIK solution (potassium 80 mEq and regular insulin 325 IU in 500 ml of 50% glucose) or equivalent volume of normal saline (control) upon anaesthetic induction until 6 h after reperfusion. The primary endpoints were to compare the concentrations of creatine kinase-MB (CK-MB) and troponin-T between the groups after reperfusion. The secondary endpoints were to compare the incidences of postoperative troponin-T >0.8 ng ml(-1) and myocardial infarction (MI) between the groups. Highest CK-MB [8.7 (4.4) vs 13.1 (7.9) ng ml(-1), P=0.006] and troponin-T [0.20 (0.13-0.49) vs 0.48 (0.18-0.91) ng ml(-1), P<0.0001] values after reperfusion were significantly lower in the GIK group compared with the control group. The area under the curve of serially measured troponin-T was also significantly smaller in the GIK group compared with the control group [0.83 (0.43-1.81) vs 0.46 (0.31-1.00), P=0.036]. Significantly fewer patients in the GIK group showed troponin-T >0.8 ng ml(-1) after reperfusion compared with the control group (3 vs 11, P=0.033). The incidence of postoperative MI was similar between the groups. GIK administration in ACS patients undergoing urgent multivessel OPCAB significantly attenuated the degree of ensuing myocardial injury without complications related to glycaemic control. Clinical Trial Registry. URL: http://clinicaltrials.gov/ct2/show/NCT01384656?term=GIK+AND+OPCAB&rank=1. Unique identification number NCT01384656.

Sensitive Troponins – Which Suits Better for Hemodialysis Patients? Associated Factors and Prediction of Mortality

BackgroundIn hemodialysis patients, elevated plasma troponin concentrations are a common finding that has even increased with the advent of newly developed sensitive assays. However, the interpretation and relevance of this is still under debate.MethodsIn this cross-sectional study, we analyzed plasma concentrations of sensitive troponin I (TnI) and troponin T (TnT) in stable ambulatory hemodialysis patients (n = 239) and investigated their associations with clinical factors and mortality.ResultsIn all of the enrolled patients, plasma TnI or TnT was detectable at a median concentration of 14 pg/ml (interquartile range: 7–29) using the Siemens TnI ultra assay and 49 pg/ml (31–74) using the Roche Elecsys high sensitive TnT assay. Markedly more patients exceeded the 99th percentile for TnT than for TnI (95% vs. 14%, p<0.0001). In a multivariate linear regression model, TnT was independently associated with age, gender, systolic dysfunction, time on dialysis, residual diuresis and systolic blood pressure, whereas TnI was independently associated with age, systolic dysfunction, pulse pressure, time on dialysis and duration of a HD session. During a follow-up period of nearly two years, TnT concentration above 38 pg/mL was associated with a 5-fold risk of death, whereas elevation of TnI had a gradual association to mortality.ConclusionIn hemodialysis patients, elevations of plasma troponin concentrations are explained by cardiac function and dialysis-related parameters, which contribute to cardiac strain. Both are highly predictive of increased risk of death.

Plasma myeloperoxidase concentration predicts the presence and severity of coronary disease in patients with chest pain and negative troponin-T

A non-negligible proportion of patients with chest pain with negative cardiac troponin may harbor a disrupted coronary plaque. A marker of plaque rupture upstream from myocardial necrosis may help identify high-risk patients among this patient population. The purpose of this study was to investigate the correlation of plasma myeloperoxidase (MPO) concentration and angiographic coronary disease among patients with suspected troponin-negative coronary syndromes. Patients presenting with chest pain and negative cardiac troponin-T concentration and undergoing coronary angiography were enrolled in our study. Plasma MPO concentration was measured using a single blood sample collected prior to cardiac catheterization. The primary angiographic endpoint was the presence of at least one coronary stenosis causing a 70% or more diameter reduction; secondary endpoints were number of diseased vessels, presence of coronary thrombus, and lesion ulceration. The main clinical endpoint was coronary revascularization. Three hundred and eighty-nine patients were enrolled. Presence of coronary stenosis causing a 70% or more diameter reduction increased with increasing quartiles of myeloperoxidase concentration (P<0.0001), as did the presence of coronary thrombus (P<0.0001) and plaque ulceration (P<0.0001). The need for percutaneous coronary revascularization also increased with increasing quartiles of systemic myeloperoxidase levels (P<0.0001). Coronary surgical revascularization did not differ among myeloperoxidase quartiles. Among patients with chest pain without troponin elevation, a single measurement of plasma MPO concentration can help identify patients with a higher risk of having significant coronary stenoses and high-risk angiographic features.

A Nanostructured Piezoelectric Immunosensor for Detection of Human Cardiac Troponin T

A piezoelectric immunosensor based on gold nanoparticles (AuNPs) co-immobilized on a dithiol-modified surface is proposed for detection of human cardiac troponin T (TnT). Anti-human troponin T (anti-TnT) antibodies were covalently immobilized on the nanostructured electrode surface by thiol-aldehyde linkages. In a homogeneous bulk solution, TnT was captured by anti-TnT immobilized on the QCM electrode. Cyclic voltammetry studies were used to characterize the AuNPs layer on the electrode surface and the anti-TnT immobilization steps. The QCM-flow immunosensor exhibited good reliability, measuring concentrations of TnT from 0.003 to 0.5 ng mL−1 in human serum with high linearity (r = 0.989; p < 0.01). The immunosensor exhibited a 7% coefficient of variation and 0.0015 ng mL−1 limit of detection, indicating a high reproducibility and sensitivity. The proposed QCM nanostructured immunosensor is easy to use and has promising potential in the diagnosis of acute myocardial infarction due to its speed and high sensitivity.

Cardiac troponin-T and the prediction of acute and long-term mortality after acute pulmonary embolism

BackgroundAlthough cardiac troponin elevation during acute pulmonary embolism (PE) predicts in-hospital death, its long-term prognostic significance, and the role of troponin-T concentration in this prediction, is unknown. Moreover, its use in acute PE in elderly populations with multiple comorbidities is not well described. MethodsConsecutive patients presenting with confirmed PE to a tertiary hospital between 2000 and 2007 with troponin-T measured were identified retrospectively and their outcomes tracked from a state-wide death registry. ResultsThere were 577 patients, (47% male) with a mean age (±standard deviation) of 70.1±15.2years, of whom 19 died during index admission. Of the 558 patients who survived to discharge, 186 patients died during a mean follow-up of 3.8±2.4years. There were 187 (32%) patients with elevated troponin-T (≥0.01μg/L). Troponin-T concentration was significantly and independently associated with in-hospital and long-term mortality whether analyzed as a continuous or categorical variable (p<0.001). However, different cut-points were required to optimally predict in-hospital and post-discharge long-term mortality in multivariate analysis. Troponin-T≥0.01μg/L was not an independent predictor of in-hospital or post-discharge survival. A cut-point of troponin-T≥0.03μg/L was required to independently predict in-hospital death (p=0.03), and troponin-T≥0.1μg/L was required to independently predict long-term mortality (hazard ratio 2.3, 95% confidence interval 1.4–3.8, p=0.001). ConclusionsTroponin-T elevation during acute PE shows a concentration-dependent relationship with acute and long-term outcome. Concentrations of troponin-T well above the threshold for detection may be required to independently contribute to prediction of outcome in elderly populations with acute PE.

Assessment of dexrazoxane as a cardioprotectant in doxorubicin-treated children with high-risk acute lymphoblastic leukaemia: long-term follow-up of a prospective, randomised, multicentre trial

Doxorubicin chemotherapy is associated with cardiomyopathy. Dexrazoxane reduces cardiac damage during treatment with doxorubicin in children with acute lymphoblastic leukaemia (ALL). We aimed to establish the long-term effect of dexrazoxane on the subclinical state of cardiac health in survivors of childhood high-risk ALL 5 years after completion of doxorubicin treatment. Between January, 1996, and September, 2000, children with high-risk ALL were enrolled from nine centres in the USA, Canada, and Puerto Rico. Patients were assigned by block randomisation to receive ten doses of 30 mg/m² doxorubicin alone or the same dose of doxorubicin preceded by 300 mg/m² dexrazoxane. Treatment assignment was obtained through a telephone call to a centralised registrar to conceal allocation. Investigators were masked to treatment assignment but treating physicians and patients were not; however, investigators, physicians, and patients were masked to study serum cardiac troponin-T concentrations and echocardiographic measurements. The primary endpoints were late left ventricular structure and function abnormalities as assessed by echocardiography; analyses were done including all patients with data available after treatment completion. This trial has been completed and is registered with ClinicalTrials.gov, number NCT00165087. 100 children were assigned to doxorubicin (66 analysed) and 105 to doxorubicin plus dexrazoxane (68 analysed). 5 years after the completion of doxorubicin chemotherapy, mean left ventricular fractional shortening and end-systolic dimension Z scores were significantly worse than normal for children who received doxorubicin alone (left ventricular fractional shortening: -0·82, 95% CI -1·31 to -0·33; end-systolic dimension: 0·57, 0·21-0·93) but not for those who also received dexrazoxane (-0·41, -0·88 to 0·06; 0·15, -0·20 to 0·51). The protective effect of dexrazoxane, relative to doxorubicin alone, on left ventricular wall thickness (difference between groups: 0·47, 0·46-0·48) and thickness-to-dimension ratio (0·66, 0·64-0·68) were the only statistically significant characteristics at 5 years. Subgroup analysis showed dexrazoxane protection (p=0·04) for left ventricular fractional shortening at 5 years in girls (1·17, 0·24-2·11), but not in boys (-0·10, -0·87 to 0·68). Similarly, subgroup analysis showed dexrazoxane protection (p=0·046) for the left ventricular thickness-to-dimension ratio at 5 years in girls (1·15, 0·44-1·85), but not in boys (0·19, -0·42 to 0·81). With a median follow-up for recurrence and death of 8·7 years (range 1·3-12·1), event-free survival was 77% (95% CI 67-84) for children in the doxorubicin-alone group, and 76% (67-84) for children in the doxorubicin plus dexrazoxane group (p=0·99). Dexrazoxane provides long-term cardioprotection without compromising oncological efficacy in doxorubicin-treated children with high-risk ALL. Dexrazoxane exerts greater long-term cardioprotective effects in girls than in boys. US National Institutes of Health, Children's Cardiomyopathy Foundation, University of Miami Women's Cancer Association, Lance Armstrong Foundation, Roche Diagnostics, Pfizer, and Novartis.

Cell free DNA detected by a novel method in acute ST-elevation myocardial infarction patients

High levels of circulating cell free DNA (CFD) have been associated with poor prognosis in various diseases. Data pertaining to CFD in acute myocardial infarction (MI) are scarce. The available data have been obtained by either electrophoresis or polymerase chain reaction. We evaluated a novel method for the detection of CFD in patients with ST elevation myocardial infarction (STEMI) and examined its correlation with established markers of necrosis and ventricular function. Serum concentrations of CFD, troponin-T and creatine kinase (CK) were measured simultaneously in 16 randomly selected acute STEMI patients upon admission and at three more time points. 47 healthy subjects served as a control group. CFD was quantified by a novel rapid fluorometric assay. Ejection fraction (EF) was assessed by echocardiography. Peak CFD levels were significantly higher in patients compared with controls (P = 0.001) and correlated with peak levels of CK and troponin-T (R = 0.79, P <0.001); R = 0.65, P = 0.006, respectively). Peak CFD levels tended to be associated with lower EF (P = 0.075). With this method, CFD levels correlated with the levels of established markers of myocardial necrosis but not with EF. The kinetic pattern of CFD release after STEMI and its prognostic value require further investigation.

Prognostic efficacy of cardiac biomarkers for mortality in dialysis patients

The high prevalence of cardiovascular mortality in the end-stage renal disease population is well established. The aim of this current study was to document the relative prognostic significance of established cardiac biomarkers troponin T (TnT), troponin I (TnI), B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-pro-BNP) in this population. A prospective cohort study of dialysis patients undertaken in a single tertiary centre in Australia. Relevant clinical and biochemical information was collected at entry and all patients followed up prospectively without any loss to follow up. End-point of interest was all-cause mortality. Statistical analysis using Cox proportional hazards was used to study relationship between competing covariates and outcome. A total of 143 patients with a mean age of 59.67 +/- 15.49 years was followed up for a median duration of 30 months. Of these patients, 89.3% were white Australians of European ancestry. Twenty-seven per cent had an established diagnosis of diabetes mellitus. The mean concentrations (+/-SD) of TnT, TnI, BNP and N-terminal peptide pro-BNP (NT-pro-BNP) were 0.08 +/- 0.04 microg/L, 0.09 +/- 0.2 microg/L, 270 +/- 117 ng/L and 1434 +/- 591 ng/L respectively. Twenty-eight subjects died during the period of follow up. By univariate analysis, all cardiac markers (TnT, TnI, BNP, NT-pro-BNP and C-reactive protein) were significantly associated with an increase in mortality. On Cox proportionate hazards analysis, only albumin and NT-pro-BNP showed a significant association with mortality, with hazard ratios of 0.834, 95% confidence interval (CI) 0.779-0.893, P < 0.001, and 1.585, 95%CI 1.160-20165, P = 0.004 respectively. In patients with end-stage renal failure on dialysis NT-pro-BNP provides greater prognostic information compared with TnT and TnI.

Troponin T and Pro–B-Type Natriuretic Peptide in Fetuses of Type 1 Diabetic Mothers

OBJECTIVECardiomyopathy is noted in up to 40% of infants of diabetic mothers, and the exact mechanisms are unknown. The aim of this study was to determine whether fetal serum markers of cardiac function differ between normal and type 1 diabetic pregnancies and to examine the relationship between these markers and fetal cardiac structure and function.RESEARCH DESIGN AND METHODSThis was a prospective observational study of 45 type 1 diabetic pregnancies and 39 normal pregnancies. All participants had concentrations of fetal pro–B-type natriuretic peptide (proBNP) and troponin-T (TnT) measured at the time of delivery. All patients with type 1 diabetes had Doppler evaluation of the umbilical artery, middle cerebral artery, and ductus venosus in the third trimester, and a subset (n = 21) had detailed fetal echocardiograms performed in each trimester.RESULTSFetal proBNP and TnT concentrations were higher in the diabetic cohort than in the normal cohort (P < 0.05). ProBNP correlated positively with interventricular septum thickness (P < 0.05) but not with cardiac function indexes in the third trimester. In patients with poor glycemic control, there was a significant positive correlation (P < 0.05) between fetal TnT and the third trimester umbilical artery pulsatility index. There were also increased levels of fetal TnT in infants with poor perinatal outcome (P < 0.05).CONCLUSIONSBiochemical markers of cardiac dysfunction are elevated in infants of diabetic mothers, especially those with cardiomyopathy or poor perinatal outcome. Hyperglycemia in early pregnancy may affect myocardial and placental development, thus contributing to the susceptibility to hypoxia seen in these infants.

Cardioprotective Effects of Nicorandil in Patients Undergoing On-Pump Coronary Artery Bypass Surgery

The purpose of this study was to assess the cardioprotective effects of nicorandil in patients undergoing coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB). A prospective, double-blind, randomized clinical study. A university hospital. Thirty-two patients undergoing elective CABG surgery. Patients were randomized into 2 groups: the nicorandil and placebo groups. In the nicorandil group, intravenous nicorandil infusion was started after the induction of anesthesia by a loading dose of 0.1 mg/kg, followed by a continuous infusion of 0.1 mg/kg/h until 2 hours after CPB, then decreased to 0.05 mg/kg/h, and discontinued at the end of surgery. The placebo group received the same volume of saline. Arterial blood was sampled, and serum troponin T (TnT) and CK-MB were measured at the following 4 stages: after the induction of anesthesia (baseline), 2 hours after CPB, the first postoperative day (POD), and the third POD. TnT concentrations were similar at baseline and increased with a peak on the first POD in both groups. In the nicorandil group, TnT concentration returned to the baseline value at the third POD, and the time course of TnT showed significantly lower levels (p = 0.012). CK-MB concentrations were similar at baseline, increased and peaked at 2 hours after CPB, and returned to the baseline on the third POD in both groups. There were no significant differences between the groups with respect to the changes in CK-MB concentrations. The nicorandil group showed lower concentrations of TnT, suggesting that intraoperative administration of nicorandil may provide a degree of myocardial protection in CABG surgery.