Cardiac troponin T predicts mortality in patients with end-stage renal disease

Predictors of lower exercise capacity in patients with cancer

Maintaining cancer patients' exercise capacity and therefore patients' ability to live a self-determined life is of huge importance, but little is known about major determinants. We sought to identify determinants of exercise capacity in patients with a broad spectrum of cancer types, who were already receiving cancer treatment or about to commence such therapy. Exercise capacity was assessed in 253 consecutive patients mostly suffering from advanced cancer using the 6-min walk test (6-MWT). All patients underwent echocardiography, physical examination, resting electrocardiogram, hand grip strength (HGS) measurement, and laboratory assessments. Patients were divided into two groups according to the median distance in the 6-MWT (459 m). Patients with lower exercise capacity were older, had significantly lower HGS and haemoglobin and higher values of high sensitive (hs) Troponin T and NT-proBNP (all p < 0.05). Whilst the co-morbidity burden was significantly higher in this group, no differences were detected for sex, body mass index, tumor type, or cachexia (all p > 0.2). Using multivariable logistic regression, we found that the presence of anaemia (odds ratio (OR) 6.172, 95% confidence interval (CI) 1.401-27.201, p = 0.016) as well as an increase in hs Troponin T (OR 3.077, 95% CI 1.202-5.301, p = 0.019) remained independent predictors of impaired exercise capacity. Increasing HGS was associated with a reduced risk of a lower exercise capacity (OR 0.896, 95% CI 0.813-0.987, p = 0.026). Screening patients for elevated hs troponin levels as well as reduced HGS may help to identify patients at risk of lower exercise capacity during cancer treatment.

Non-Ischemic, Non-Hypoxic Myocardial Injury, and Long-Term Mortality in Patients with Coronavirus Disease 2019: A Retrospective Cohort Study

OBJECTIVE

Cardiac damage is commonly reported in patients with coronavirus disease 2019 (COVID-19) but its prevalence and impact on the long-term survival of patients remain uncertain. This study aimed to explore the prevalence of myocardial injury and assess its prognostic value in patients with COVID-19.

METHODS

A single-center, retrospective cohort study was performed at the Affiliated Hospital of Jianghan University. Data from 766 patients with confirmed COVID-19 who were hospitalized from December 27, 2019 to April 25, 2020 were collected. Demographic, clinical, laboratory, electrocardiogram, treatment data and all-cause mortality during follow-up were collected and analyzed.

RESULTS

Of the 766 patients with moderate to critically ill COVID-19, 86 (11.2%) died after a mean follow-up of 72.8 days. Myocardial injury occurred in 94 (12.3%) patients. The mortality rate was 64.9% (61/94) and 3.7% (25/672) in patients with and without myocardial injury, respectively. Cox regression showed that myocardial injury was an independent risk factor for mortality (hazard ratio: 8.76, 95% confidence interval: 4.76-16.11, P < 0.001). Of the 90 patients with myocardial injury with electrocardiogram results, sinus tachycardia was present in 29, bundle branch block in 26, low voltage in 10, and abnormal T-wave in 53.

CONCLUSIONS

COVID-19 not only involves pneumonia but also cardiac damage. Myocardial injury is a common complication and an independent risk factor for mortality in COVID-19 patients.

Interpretation of Cardiac and Non-Cardiac Causes of Elevated Troponin T Levels in Non-Acute Coronary Syndrome Patients in the Emergency Department

The definition of myocardial infarction was updated in 2000 to include an elevation of cardiac troponin T or I (cTnT or xTnI) alongside clinical evidence of myocardial infarction. The redefinition was jointly done by the American College of Cardiology Committee and the European Society of Cardiology. Since then, cardiac troponin T and I have assumed the position as the primary biochemical markers for diagnosing myocardial infarction. The high sensitivity of cardiac troponin for myocardial necrosis influenced the decision to include cardiac troponins (cTn) in the diagnostic pathway. An elevated cTn level indicates the presence of myocardial injury. However, it does not give the underlying reason for the damage. Apart from acute myocardial infarction (AMI), a range of potential diseases feature troponin release, including heart failure, acute pulmonary embolism, end-stage renal disease, and myocarditis. However, regardless of the mechanism that triggers the release from cardiac myocytes, elevated cTnI and cTnT typically implies a poor prognosis. This review attempts to explain both the cardiac and non-cardiac causes of increased cTnT in emergency department patients.

Frontal QRS-T angle as a predictive marker for myocardial damage in acute carbon monoxide poisoning

INTRODUCTION

The present study was undertaken to investigate the prognostic value of the frontal QRS-T angle associated with adverse cardiac outcomes in patients with carbon monoxide (CO) poisoning in early stages in the emergency department.

MATERIALS AND METHODS

The data of 212 patients with CO poisoning who were admitted to the ED between January 2010 and May 2020 were retrospectively analyzed. The frontal QRS-T angle was obtained from the automatic reports of the EKG device.

RESULTS

Compared to patients without myocardial damage, among patients with myocardial damage, statistically high creatinine, creatine kinase MB, cardiac troponin I, and frontal QRS-T angle values were found (p < 0.001 for all parameters), while the saturation of arterial blood pH and arterial oxygen values were found to be lower (p = 0.002 and p < 0.001, respectively). The frontal QRS-T angle values were correlated with creatine kinase, creatine kinase-MB, cardiac troponin I, and oxygen saturation (SpO₂) in arterial blood (r = 0. 232, p = 0.001; r = 0. 253, p = < 0.001; r = 0. 389, p = < 0.001; r = -0. 198, p = 0.004, respectively). The optimum cut-off value of the frontal QRS-T angle was found to be 44.5 (area under the curve: 0.901, 95% confidence interval: 0.814-0.988, sensitivity: 87%, specificity: 84%).

CONCLUSIONS

The frontal QRS-T angle, a simple and inexpensive parameter that can be easily obtained from 12-lead surface electrocardiography, can be used as an early indicator in the detection of myocardial damage in patients with CO poisoning.

Factors associated with nutritional risk in patients receiving haemodialysis assessed by Nutritional Risk Screening 2002 (NRS2002)

BACKGROUND

Nutritional Risk Screening 2002 is recommended as a screening tool to identify patients at risk of undernutrition for all patients in hospitals by the European Society of Clinical Nutrition and Metabolism. Nutritional risk is associated with increased morbidity and mortality in patients, and it is common among patients on haemodialysis. Factors associated with nutritional risk that could facilitate the screening/diagnostic procedures are warranted.

OBJECTIVES

Identification of factors that are associated with nutritional risk in patients with end-stage renal disease treated with haemodialysis.

DESIGN AND PARTICIPANTS

Single-centre, cross-sectional study in patients receiving haemodialysis (n = 53) were screened for nutritional risk using Nutritional Risk Screening 2002. Associations were made with data on dietary intake by 24-h dietary recall, and measurement of body composition, anthropometric measurements and biochemical variables.

RESULTS

Nutritional risk was common among patients on haemodialysis (26%), and was associated with low energy and protein intake, and low pre-albumin concentrations also after adjustments for age and sex. Nutritional risk was neither associated with diabetes nor duration of dialysis treatment.

CONCLUSION

Measurement of pre-albumin and dietary assessment using a 24-h dietary recall can support the identification of patients receiving haemodialysis at nutritional risk.

Presepsin for pre-operative prediction of major adverse cardiovascular events in coronary heart disease patients undergoing noncardiac surgery: Post hoc analysis of the Leukocytes and Cardiovascular Peri-operative Events-2 (LeukoCAPE-2) Study

BACKGROUND

Accurate pre-operative evaluation of cardiovascular risk is vital to identify patients at risk for major adverse cardiovascular and cerebrovascular events (MACCE) after noncardiac surgery. Elevated presepsin (sCD14-ST) is associated with peri-operative MACCE in coronary artery disease (CAD) patients after noncardiac surgery.

OBJECTIVES

Validating the prognostic utility of presepsin for MACCE after noncardiac surgery.

DESIGN

Prospective patient enrolment and blood sampling, followed by post hoc evaluation of pre-operative presepsin for prediction of MACCE.

SETTING

Single university centre.

PATIENTS

A total of 222 CAD patients undergoing elective, inpatient noncardiac surgery.

INTERVENTION

Pre-operative presepsin measurement.

MAIN OUTCOME MEASURES

MACCE (cardiovascular death, myocardial infarction, myocardial ischaemia and stroke) at 30 days postsurgery.

RESULTS

MACCE was diagnosed in 23 (10%) patients. MACCE patients presented with increased pre-operative presepsin (median [IQR]; 212 [163 to 358] vs. 156 [102 to 273] pgml, P = 0.023). Presepsin exceeding the previously derived threshold of 184 pg ml was associated with increased 30-day MACCE rate. After adjustment for confounders, presepsin more than 184 pg ml [OR = 2.8 (95% confidence interval 1.1 to 7.3), P = 0.03] remained an independent predictor of peri-operative MACCE. Predictive accuracy of presepsin was moderate [area under the curve (AUC) = 0.65 (0.54 to 0.75), P = 0.023]. While the basic risk model of revised cardiac risk index, high-sensitive cardiac troponin T and N-terminal fragment of pro-brain natriuretic peptide resulted in an AUC = 0.62 (0.48 to 0.75), P = 0.072, addition of presepsin to the model led to an AUC = 0.67 (0.56 to 0.78), P = 0.009 and (ΔAUC = 0.05, P = 0.438). Additive risk predictive value of presepsin was demonstrated by integrated discrimination improvement analysis (integrated discrimination improvement = 0.023, P = 0.022). Net reclassification improvement revealed that the additional strength of presepsin was attributed to the reclassification of no-MACCE patients into a lower risk group.

CONCLUSION

Increased pre-operative presepsin independently predicted 30-day MACCE in CAD patients undergoing major noncardiac surgery. Complementing cardiovascular risk prediction by inflammatory biomarkers, such as presepsin, offers potential to improve peri-operative care. However, as prediction accuracy of presepsin was only moderate, further validation studies are needed.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03105427.

Chronic elevation of cardiac troponin I predicts the extent of coronary disease in hemodialysis patients presenting with acute enzyme elevation

Introduction

Elevation of cardiac troponin I (cTn-I) is associated with coronary artery disease (CAD) in asymptomatic patients with end-stage renal disease (ESRD) receiving hemodialysis. We aim to investigate the diagnostic value of chronically elevated cTn-I in ESRD patients presenting with an acute rise in serum cTn-I levels.

Methods

We performed a retrospective analysis of 364 patients. Using coronary angiography, we correlated baseline elevation of cTn-I with the severity of CAD when hemodialysis patients present with acute symptomatic elevation in serum cTn-I.

Results

In hemodialysis patients presenting with a rise in serum cTn-I above baseline levels, 59% had severe CAD, and 17% had no angiographic evidence of CAD. Hemodialysis patients with severe CAD had significantly higher baseline cTn-I levels compared to patients with non-severe CAD or normal coronaries (p < 0.0001). Baseline elevation of cTn-I in the severe CAD group was correlated with the degree of CAD occlusion (r2 0.56, p < 0.0001), fitting a positive linear model. Furthermore, baseline cTn-I differentiates between patients with and without severe CAD with a test accuracy of 0.72 (95% CI, 0.69-0.75, p < 0.001). At a value of ≥0.2 ng/mL (cutoff for myocardial necrosis), the specificity of baseline cTn-I for underlying severe CAD was 0.95.

Conclusions

Elevated baseline cTn-I has good accuracy for anticipating more advanced angiographic CAD when hemodialysis patients present with a symptomatic rise in serum cTn-I above baseline levels. Baseline elevation of cTn-I can be used for cardiac disease risk management in hemodialysis patients presenting with symptoms suggestive of CAD.

Serum Folate and All-Cause Mortality is of Non-Linear Relationship Among Population with Chronic Kidney Disease: A Retrospective Cohort Study

AIM

A transition toward high serum folate concentrations has been noticed following the mandatory folate fortification. To explore this further, we studied the relationship between folate and health outcomes in population with chronic kidney disease (CKD).

METHODS

We retrospectively explored the relationships between serum folate and risk of all-cause death in this population. We analyzed data of 2142 subjects with CKD who participated in the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Vital status was followed through December 31, 2006.

RESULTS

Cox regression was used to estimate hazard ratios (HRs) of mortality for individuals with serum folate in rest quintiles compared with individuals with the fourth quintile. After an average follow-up of 57.4 months with 157 deaths recorded, a reversed J-shaped association was revealed after conducting multivariable adjustment. The mortality rate in population with lower and higher folate levels were 8.29% and 12.67%, respectively, and the corresponding adjusted HRs were 2.41 (95% confidence interval, CI=1.32-4.40) and 2.10 (1.20-3.70). Kaplan-Meier curve showed survival benefits for the fourth quintile of serum folate as compared to the first and fifth quintile.

CONCLUSION

Serum folate concentrations may influence all-cause mortality in a non-linear pattern in the CKD population. It is reasonable to recommend periodic surveillance in the CKD population to maintain the serum folate concentration in an appropriate level.

Association of plasma macrophage colony-stimulating factor with cardiovascular morbidity and all-cause mortality in chronic hemodialysis patients

Background

Cardiovascular disease (CVD) events are the main cause of death in long-term hemodialysis (HD) patients. Macrophage colony- stimulating factor (M-CSF) is actively involved in the formation of atherosclerosis and causes plaque instability, thrombosis and the development of acute coronary syndromes. However, little information is available on the role of M-CSF in HD patients. We aimed to investigate the association between plasma M-CSF levels and CVD events as well as all-cause mortality in patients undergoing long-term HD.

Methods

Fifty two HD patients and 8 healthy controls were recruited in this study. HD patients were followed up from September 2014 to May 2017. The primary end point was CVD event, the secondary outcome was death from any cause. Patients were divided into two groups with low and high M-CSF levels based on the optimal cut-off value determined by the ROC curve. Cox regression analyses were used to assess the predictive value of plasma M-CSF for CVD events and all-cause mortality in HD patients. We tested the levels of plasma M-CSF and other inflammatory cytokines in surviving HD patients using ELISA or CBA kit.

Results

The average plasma level of M-CSF in 52 patients was approximately twice that of healthy controls (992.4 vs. 427.2 pg/mL; p <  0.05). During 32 months of follow-up, 26 patients (50.0%) had at least one CVD event and 8 patients (15.4%) died. The mean plasma M-CSF concentration increased in survivors after follow-up compared to that detected at baseline (1277.8 ± 693.3 vs. 997.2 ± 417.4 pg/mL; p <  0.05). Multivariate Cox regression analysis showed that plasma M-CSF is an independent risk factor for CVD events in HD patients (p <  0.05). In the Cox regression model after adjusting for gender and age, high M-CSF levels were related to an increased risk of all-cause death (p <  0.05). We also found that M-CSF levels were positively correlated with IL-6 and IL-18 levels (both p < 0.05), which are the major pathogentic cytokines that contribute to HD-related CVD events.

Conclusion

M-CSF is a prognostic factor for CVD events and all-cause mortality in HD patients.

[Troponin elevation-does every patient require coronary angiography?]

The determination of high-sensitivity troponin remains the gold standard in patients with acute chest pain and allows the early diagnosis and therapy of patients with acute myocardial infarction (AMI). Increased cardiac troponin levels are highly specific for myocardial damage. However, elevated troponin levels are not equivalent to AMI and therefore the clinical presentation and the electrocardiogram of each patient must be taken into account. Elevated troponin levels are found in numerous diseases but not every patient needs invasive coronary angiography.

Challenges in high-sensitive troponin assay interpretation for intensive therapy

Cardiac troponins T and I are considered highly sensitive and specific markers for the diagnosis of acute myocardial infarction. Currently, a series of nonprimary cardiac abnormalities may manifest as an elevation in high-sensitive assays. The reduction in their detection limits has allowed earlier diagnosis and the use of evidence-based therapeutic measures; however, this characteristic has increased the spectrum of detectable noncoronary heart diseases, which poses challenges for characterizing acute coronary syndromes and creates a new role for these tests in known disorders in intensive care units, especially sepsis. Management of patients through a greater understanding of how these markers behave should be re-evaluated to ensure their correct interpretation.

High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function

Dialysate calcium concentration (d[Ca]) might have a cardiovascular impact in patients on haemodialysis (HD) since a higher d[Ca] determines better hemodynamic tolerability. We have assessed the influence of d[Ca] on global longitudinal strain (GLS) by two-dimensional echocardiography using speckle-tracking imaging before and in the last hour of HD. This is an observational crossover study using d[Ca] 1.75 mmol/L and 1.25 mmol/L. Ultrafiltration was the same between interventions; patients aged 44 ± 13 years (N = 19). The 1.75 mmol/L d[Ca] was associated with lighter drop of blood pressure. Post HD serum total calcium was higher with d[Ca] 1.75 than with 1.25 mmol/L (11.5 ± 0.8 vs. 9.1 ± 0.5 mg/dL, respectively, p < 0.01). In almost all segments strain values were significantly worse in the peak HD with 1.75 mmol/L d[Ca] than with 1.25 mmol/L d[Ca]. GLS decreased from −19.8 ± 3.7% at baseline to −17.3 ± 2.9% and −16.1 ± 2.6% with 1.25 d[Ca] and 1.75 d[Ca] mmol/L, respectively (p < 0.05 for both d[Ca] vs. baseline and 1.25 d[Ca] vs. 1.75 d[Ca] mmol/L). Factors associated with a worse GLS included transferrin, C-reactive protein, weight lost, and post dialysis serum total calcium. We concluded that d[Ca] of 1.75 mmol/L was associated with higher post dialysis serum calcium, which contributed to a worse ventricular performance. Whether this finding would lead to myocardial stunning needs further investigation.

Folic Acid and Vitamin B12 Administration in CKD, Why Not?

Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Since traditional risk factors cannot fully explain such increased cardiovascular risk, interest in non-traditional risk factors, such as hyperhomocysteinemia and folic acid and vitamin B12 metabolism impairment, is growing. Although elevated homocysteine blood levels are often seen in patients with CKD and ESRD, whether hyperhomocysteinemia represents a reliable cardiovascular and mortality risk marker or a therapeutic target in this population is still unclear. In addition, folic acid and vitamin B12 could not only be mere cofactors in the homocysteine metabolism; they may have a direct action in determining tissue damage and cardiovascular risk. The purpose of this review was to highlight homocysteine, folic acid and vitamin B12 metabolism impairment in CKD and ESRD and to summarize available evidences on hyperhomocysteinemia, folic acid and vitamin B12 as cardiovascular risk markers, therapeutic target and risk factors for CKD progression.

Association of serum vitamin B12 and folate with mortality in incident hemodialysis patients

Background

Vitamin B12 (B12) and folate are essential vitamins that play important roles in physiological processes. In the general population, many studies have evaluated the association of these vitamins with clinical outcomes, yet this association in hemodialysis (HD) patients remains unclear.

Methods

We examined the association of serum folate and B12 with mortality in a 5-year cohort of 9517 (folate) and 12 968 (B12) HD patients using Cox models with hierarchical adjustment for sociodemographics, comorbidities, and laboratory variables associated with the malnutrition and inflammation complex syndrome. The associations of baseline B12 and folate (separately) with all-cause mortality were evaluated across five categories of B12 [<400 (reference), 400-<550, 550-<650, 650-<750 and ≥750 pg/mL] and folate [<6.2, 6.2-<8.4, 8.4-<11 (reference), 11-<14.3 and ≥14.3 ng/mL].

Results

The study cohort with B12 measurements had a mean ± standard deviation age of 63 ± 15 years, among whom 43% were female, 33% were African-American, and 57% were diabetic. Higher B12 concentrations ≥550 pg/mL were associated with a higher risk of mortality after adjusting for sociodemographic and laboratory variables. However, only lower serum folate concentrations <6.2 ng/mL were associated with a higher risk of all-cause mortality when adjusted for sociodemographic variables [adjusted hazard ratio (95% confidence-interval): 1.18 (1.03-1.35)].

Conclusions

Higher B12 concentrations are associated with higher all-cause mortality in HD patients independent of sociodemographics and laboratory variables, whereas lower folate concentrations were associated with higher all-cause mortality after accounting for sociodemographic variables. Further studies are warranted to determine the optimal B12 and folate level targets in this population.

Development of quantum dot-based biosensors: principles and applications

We review the recent advances in quantum dot-based biosensors and focus on quantum dot-based fluorescent, bioluminescent, chemiluminescent, and photoelectrochemical biosensors.

Cardiac troponin T as a predictor of cardiac death in patients with left ventricular dysfunction

Background

Cardiac troponin T (cTnT) has been reported to be associated with cardiac mortality.

In the present study, we evaluated the role of routine assessment of cTnT as a predictor of future cardiac death in patients with left ventricular (LV) dysfunction.

Methods

Patients who were eligible for prophylactic implantable cardioverter defibrillator (ICD) were included from cardiac catheterization database. Inclusion criteria were patients with LV ejection fraction of ≤ 35% and with New York Heart Association (NYHA) ≥class II. Exclusion criteria were patients with acute coronary syndrome, ICD for secondary prevention, NYHA class IV, and lack of data. The final study patients were divided into the following three groups in accordance with two quartile points of serum cTnT levels: low cTnT, intermediate cTnT, and high cTnT groups. The primary endpoint of this study was cardiac death.

Results

A total of 70 patients were included (mean age, 62±13 years; male individuals, 56; ischemic, 36; and non-ischemic, 34). During the observation period of 2.2 years, cardiac death was observed in 17 patients (fatal arrhythmic event, 9; heart failure, 7; myocardial infarction, 1). In the Kaplan–Meier analysis, the high cTnT group showed the highest risk among all the groups (p<0.001). Even in sub-analyses for ischemic and non-ischemic patients, the results were the same, and the high cTnT group showed the highest event rate (p<0.05). In contrast, no cardiac death was observed in the low cTnT group.

Conclusion

The cTnT levels in a stable state were associated with cardiac death in patients with LV dysfunction, even in those with non-ischemic diseases.

Acute kidney injury induces high-sensitivity troponin measurement changes after cardiac surgery

BACKGROUND

The value of cardiac troponin as a risk assessment tool for cardiac disease in the setting of end-stage renal diseases (ESRD) is not equivalent to its value in those with normal renal function. This consideration had not been studied in settings of acute kidney injury (AKI). We aim to explore the diagnostic value of high sensitive troponin T (hsTnT) in the settings of cardiac surgery-induced AKI.

METHODS

Single center observational retrospective study. Based on the AKI Network, patients divided into 2 groups, group I without AKI (259 patients) and group II with AKI (100 patients) where serial testing of hsTnT and creatine kinase (CK)-MB were followed in both groups. Patients with (ESRD) were excluded.

RESULTS

The mean age in our study was 55.1 ± 10.2 years. High association of AKI (27.8%) was found in our patients. Both groups were matched regarding the age, gender, body mass index, the association of diabetes or hypertension, and Euro score. AKI group had significantly higher mortality 5% vs group I 1.1% (p = 0.03). The hsTnt showed a significant sustained rise in the AKI group as compared to the non-AKI group, however CK-MB changes were significant initially but not sustained. The AKI group was more associated with heart failure 17.9% vs 4.9% (p = 0.001); and post-operative atrial fibrillation, 12.4% vs 2.9% (p = 0.005). Lengths of ventilation, stays in ICU and in hospital were significantly higher in the AKI group.

CONCLUSIONS

Unlike the CK-MB profile, the hsTnT showed significant changes between both groups all over the course denoting possible delayed clearance in patients with AKI.

microRNA assays for acute coronary syndromes

microRNAs are promising biomarkers for diverse cardiovascular diseases. While quantification of the small non-coding RNAs is routinely performed in the research laboratory, clinical-grade assessment of microRNAs in central laboratory environments or point-of-care testing is still in its infancy. In this review, we provide an overview on microRNAs as biomarkers for acute coronary syndromes and highlight promising technical approaches for microRNA-based assays systems.

Cardiac troponin T elevation at dialysis initiation is associated with all-cause and cardiovascular mortality on dialysis in patients without diabetic nephropathy

BACKGROUND

It is not known whether asymptomatic cardiac troponin T (cTnT) elevation is associated with all-cause or cardiovascular mortality in non-diabetic and advanced chronic kidney disease (CKD) patients.

METHODS

We measured cTnT in 248 consecutive patients at 1-2 weeks before dialysis initiation between March 2005 and August 2010 and followed them prospectively. A Cox proportional hazard model was used to investigate the relationship between cTnT and all-cause and cardiovascular mortality on dialysis.

RESULTS

The median age of the patients was 67 years (male 59.3 %), and the prevalence of diabetic nephropathy (DN) was 38.3 %. Asymptomatic cTnT elevation (>0.01 ng/mL) was observed in 196 (79 %) and 111 (73 %) patients among the overall patients and among patients without DN, respectively. A total of 51 patients died during a median follow-up period of 31.6 months. The cTnT level was associated with all-cause [hazard ratio (HR) 1.453; 95 % confidence interval (CI) 1.093-1.931; P = 0.010] and cardiovascular mortality [HR 1.973; 95 % CI 1.127-3.454; P = 0.017] on dialysis after extensive adjustment in the overall patient population. Patients without DN showed similar associations as those for the overall patient population (all-cause mortality: HR 1.566; 95 % CI 1.048-2.339; P = 0.029 and cardiovascular mortality: HR 2.657; 95 % CI 1.115-6.328; P = 0.027).

CONCLUSION

Asymptomatic cTnT elevation might be strongly associated with all-cause and cardiovascular mortality in patients without DN, as well as in the overall advanced CKD patients. We suggest that cardiovascular risk in patients with pre-dialysis CKD should be stratified according to cTnT levels.

Sudden cardiac death and chronic kidney disease: From pathophysiology to treatment strategies

Chronic kidney disease (CKD) patients demonstrate higher rates of cardiovascular mortality and morbidity; and increased incidence of sudden cardiac death (SCD) with declining kidney failure. Coronary artery disease (CAD) associated risk factors are the major determinants of SCD in the general population. However, current evidence suggests that in CKD patients, traditional cardiovascular risk factors may play a lesser role. Complex relationships between CKD-specific risk factors, structural heart disease, and ventricular arrhythmias (VA) contribute to the high risk of SCD. In dialysis patients, the occurrence of VA and SCD could be exacerbated by electrolyte shifts, divalent ion abnormalities, sympathetic overactivity, inflammation and iron toxicity. As outcomes in CKD patients after cardiac arrest are poor, primary and secondary prevention of SCD and cardiac arrest could reduce cardiovascular mortality in patients with CKD.

Relationship between high sensitivity troponins and estimated glomerular filtration rate

BACKGROUND

Diagnosis of acute coronary syndrome may be challenging because of high troponin concentrations in patients with chronic kidney disease.

OBJECTIVE

the aim of this study is to investigate the difference between high sensitivity troponin T and troponin I in four groups of patients separated according to eGFR values and the effect of renal function both on troponin T and troponin I.

METHODS

119 outpatients were divided into 4 groups according to their eGFR values as Group 1: eGFR<30, Group 2: eGFR between 30 and 60, Group 3: eGFR between 60 and 90 and Group 4: eGFR >90mL/min/1.73m(2). The cardiac troponin T and I concentrations were measured concurrently.

RESULTS

Troponin T values of all patients who have eGFR values lower than 30mL/min/1.73m(2) were above the decision point, but cTnI values of only 2 patients were above the decision limit (40ng/L) in this group. There was a strong and significant negative relationship between eGFR and hs-cTnT [log(y)=2.3-0.72log(x); R(2)=0.625] whereas there was no significant relationship between eGFR and hs-cTnI [log(y)=1.28-0.08log(x); R(2)=0.013] when eGFR was taken into consideration as a continuous variable.

CONCLUSION

In this study, we found that cTnT increases with decreasing eGFR values, but cTnI is not affected by the change in eGFR values.

Diagnosis of Acute Myocardial Infarction in Hemodialysis Patients With High-Sensitivity Cardiac Troponin T Assay

Context

Cardiac troponins have become the gold standard for diagnosing acute myocardial infarction (AMI) in the general population; however, their diagnostic accuracy for hemodialysis (HD) patients presenting with chest pain or dyspnea is uncertain.

Objective

To examine the diagnostic accuracy of high-sensitivity cardiac troponin T (hs-cTnT) assay for AMI in HD patients.

Design

In this prospective study, we enrolled 670 consecutive stable HD patients presenting with chest pain or dyspnea on routine predialysis therapy in the nephrology department. Receiver operating characteristic (ROC) curves were used to examine the diagnostic accuracy of hs-cTnT levels at enrollment in HD patients presenting with chest pain or dyspnea, and the dynamic change in these levels after 3 hours.

Results

Acute myocardial infarction was the adjudicated final diagnosis in 12% of HD patients. Among patients with a final diagnosis other than AMI, 97% had a plasma hs-cTnT concentration above the 99th percentile. At the time of enrollment, the area under the ROC curve of hs-cTnT levels for diagnosis of AMI was 0.68 (95% confidence interval [CI], 0.62–0.74; P &lt; .001) with a cutoff value of 107.7 ng/L; the relative change after 3 hours was 0.90 (95% CI, 0.82–0.96, P &lt; .001) with a cutoff value of 24%, and the absolute change was 0.88 (95% CI, 0.82–0.94, P &lt; .001) with a cutoff value of 32.6 ng/L. The prognostic value for 40-day mortality varied with the magnitude of elevation in hs-cTnT levels.

Conclusions

Tracking the dynamic change in hs-cTnT levels during the short term significantly increased this measure's diagnostic accuracy for AMI in HD patients.

Creatine-kinase and dialysis patients, a helpful tool for stratifying cardiovascular risk?

BACKGROUND AND AIMS

Hemodialysis patients have an enhanced risk for cardiovascular events. Cardiac biomarkers provide useful information for stratifying their risk. However the prognosis value of creatine kinase MB isoenzyme (CKMB) has not yet been validated in this population. The aim of the present study is to determine the predictable value of CK-MB in hemodialysis.

METHODS

A cohort of 211 hemodialysis patients (58.3% male, median age 73 (60-80) years) were followed for 39 (19-56) months. Cardiac biomarkers including CKMB were recorded at baseline. Factors associated to CKMB and prognosis value of this biomarker was studied.

RESULTS

The median value of CKMB was 1 (1-2) ng/mL with no patient exceeding normal laboratory values. Previous heart disease, diabetes mellitus, peripheral vascular disease and systolic and diastolic dysfunction were associated with higher levels of CKMB. Ninety-four patients (44.5%) cardiovascular events were recorded. CKMB levels ≥2ng/mL was independently associated to cardiovascular events during the follow up after adjusting. Adding CKMB to a model including several variables for predicting cardiovascular events, resulted in 17% improvement in risk discrimination (IDI) with a relative IDI of 9.9% (p=0.04).

CONCLUSIONS

CKMB is a good marker for stratifying cardiovascular risk in hemodialysis patients and adds prognosis information to other well known independent predictors for cardiovascular events.

Multiple biomarkers including cardiac troponins T and I measured by high-sensitivity assays, as predictors of long-term mortality in patients with chronic renal failure who underwent dialysis

There is a high cardiac mortality in patients on long-term renal dialysis. No studies have reported long-term outcomes relating to both high-sensitivity cardiac troponin T (hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) in these patients. Patients who underwent long-term dialysis at the Canberra Hospital had blood samples collected for both cardiac and other biomarkers. Samples were stored at -80°C until analysis. Mortality data were collected at 5 years, and univariate and multivariate analyses were performed to identify which biomarkers were predictive of mortality at 5 years. After multivariate analysis, albumin, C-reactive protein (CRP), and hs-cTnT remained independently predictive of all-cause mortality, with hs-cTnT having the highest hazard ratio. If hs-cTnT was excluded from the analysis, then hs-cTnI was independently predictive of mortality. For hs-cTnT, for both genders, the ninety-ninth percentile, derived from a population with subjects with subclinical disease excluded, served as an excellent partition between survivors and nonsurvivors. Receiver-operating characteristic curve analysis for hs-cTnT had area under the curve of 0.798 and for hs-cTnI of 0.774. Kaplan-Meier curves for the aggregation of albumin, CRP, and hs-cTnT showed a stronger predictive power with receiver-operating characteristic area under the curve of 0.805. The addition of echocardiographic data in an analysis of all patients who had an echocardiogram for clinical reasons (n = 105) did not alter the final observations in this subgroup. In conclusion, hs-cTnT retains a superior predictive power in a dialysis-dependent population for identifying those at risk for death and when aggregated with albumin and CRP also has substantial additive value for identifying mortality risk in a renal-dialysis population.

Cardiovascular biomarkers in chronic kidney disease: state of current research and clinical applicability

The high incidence of cardiovascular events in chronic kidney disease (CKD) warrants an accurate evaluation of risk aimed at reducing the burden of disease and its consequences. The use of biomarkers to identify patients at high risk has been in use in the general population for several decades and has received mixed reactions in the medical community. Some practitioners have become staunch supporters and users while others doubt the utility of biomarkers and rarely measure them. In CKD patients numerous markers similar to those used in the general population and others more specific to the uremic population have emerged; however their utility for routine clinical application remains to be fully elucidated. The reproducibility and standardization of the serum assays are serious limitations to the broad implementation of these tests. The lack of focused research and validation in randomized trials rather than ad hoc measurement of multiple serum markers in observational studies is also cause for concern related to the clinical applicability of these markers. We review the current literature on biomarkers that may have a relevant role in field of nephrology.

Cardiac troponin and C-reactive protein for predicting all-cause and cardiovascular mortality in patients with chronic kidney disease: a meta-analysis

Elevated serum levels of cardiac troponin and C-reactive protein are associated with all-cause and cardiovascular mortality in patients with end-stage renal disease. However, the relationship between these two biomarker levels and mortality in patients with chronic kidney disease remains unclear. We conducted a meta-analysis to quantify the association of cardiac troponin and C-reactive protein levels with all-cause and cardiovascular mortality in patients with chronic kidney disease. Relevant studies were identified by searching the MEDLINE database through November 2013. Studies were included in the meta-analysis if they reported the long-term all-cause or cardiovascular mortality of chronic kidney disease patients with abnormally elevated serum levels of cardiac troponin or C-reactive protein. Summary estimates of association were obtained using a random-effects model. Thirty-two studies met our inclusion criteria. From the pooled analysis, cardiac troponin and C-reactive protein were significantly associated with all-cause (HR 2.93, 95% CI 1.97-4.33 and HR 1.21, 95% CI 1.14-1.29, respectively) and cardiovascular (HR 3.27, 95% CI 1.67-6.41 and HR 1.19, 95% CI 1.10-1.28, respectively) mortality. In the subgroup analysis of cardiac troponin and C-reactive protein, significant heterogeneities were found among the subgroups of population for renal replacement therapy and for the proportion of smokers and the C-reactive protein analysis method. Elevated serum levels of cardiac troponin and C-reactive protein are significant associated with higher risks of all-cause and cardiovascular mortality in patients with chronic kidney disease. Further studies are warranted to explore the risk stratification in chronic kidney disease patients.

Placental Growth Factor as a Predictor of Cardiovascular Events in Patients with CKD from the NARA-CKD Study

Placental growth factor (PlGF) contributes to atherogenesis through vascular inflammation and plaque destabilization. High levels of PlGF may be associated with mortality and cardiovascular disease, but the relationship between PlGF level and adverse outcomes in patients with CKD is unclear. We conducted a prospective cohort study of 1351 consecutive participants with CKD enrolled in the Novel Assessment of Risk management for Atherosclerotic diseases in CKD (NARA-CKD) study between April 1, 2004, and December 31, 2011. During a median follow-up of 3 years, 199 participants died and 383 had cardiovascular events, defined as atherosclerotic disease or heart failure requiring hospitalization. In adjusted analyses, mortality and cardiovascular risk increased in each successive quartile of serum PlGF level; hazard ratios (HRs) (95% confidence intervals [95% CIs]) for mortality and cardiovascular risk, respectively, were 1.59 (0.83 to 3.16) and 1.55 (0.92 to 2.66) for the second quartile, 2.97 (1.67 to 5.59) and 3.39 (2.20 to 5.41) for the third quartile, and 3.87 (2.24 to 7.08) and 8.42 (5.54 to 13.3) for the fourth quartile. The composite end point of mortality and cardiovascular events occurred during the study period in 76.4% of patients in both the highest PlGF quartile (≥19.6 pg/ml) and the lowest eGFR tertile (<30 ml/min per 1.73 m(2)). The association between PlGF and mortality or cardiovascular events was not attenuated when participants were stratified by age, sex, traditional risk factors, and eGFR. These data suggest elevated PlGF is an independent risk factor for all-cause mortality and cardiovascular events in patients with CKD.

Utility of traditional circulating and imaging-based cardiac biomarkers in patients with predialysis CKD

Cardiac biomarkers, such as cardiac troponin T (cTnT), brain natriuretic peptide (BNP), and N-terminal-pro-BNP (NT-pro-BNP), are commonly used to diagnose acute coronary syndrome and congestive heart failure exacerbation in symptomatic patients. Levels of these biomarkers are frequently chronically elevated in asymptomatic patients with ESRD who are receiving maintenance dialysis. Other imaging biomarkers commonly encountered in nephrologists' clinical practice, such as coronary artery calcium measured by computed tomography, left ventricular hypertrophy, and carotid intima-media thickness, are also frequently abnormal in asymptomatic patients with ESRD. This article critically reviews the limited observational data on associations between cTnT, BNP, NT-pro-BNP, coronary artery calcium, left ventricular hypertrophy, and carotid intima-media thickness with cardiovascular events and death in non-dialysis-dependent patients with CKD. Although sufficient evidence suggests that these biomarkers may be used for prognostication, the diagnostic utility of cTnT, BNP, and NT-pro-BNP remain challenging in patients with CKD. Decreased renal clearance may affect the plasma levels of these biomarkers, and upper reference limits were originally derived in patients without CKD. Until better data are available, higher cutoffs, or a rise in level compared with previous values, have been proposed to help distinguish acute myocardial infarction from chronic elevations of cTnT in symptomatic patients with CKD. Additionally, it is not known whether these biomarkers are modifiable and amenable to interventions that could change hard clinical outcomes in patients with CKD not yet undergoing long-term dialysis.

Review article: elevated troponin: diagnostic gold or fool's gold?

Troponin is a highly sensitive biomarker of myocardial injury and has been used extensively in everyday clinical practice in the community as well as in hospitals for the diagnosis of acute myocardial infarction (AMI) and for risk stratification of patients with acute coronary symptoms. Dynamic elevations in biomarkers (troponin) are considered fundamental to the diagnosis of AMI. Unfortunately, many clinical conditions can cause troponin elevation in the absence of myocardial ischaemia, and elevated levels sometimes pose a diagnostic dilemma. In some cases, inappropriate diagnosis of 'AMI' based primarily on a raised troponin can have a deleterious impact on an individual, including on driving, insurance and other medicolegal matters. An incorrect diagnosis of myocardial infarction can also lead to the oversight of serious life-threatening alternative causes of troponin elevation (e.g. pulmonary embolism). This article discusses the role of troponin in our everyday clinical practice in the ED.

Decision limits and the reporting of cardiac troponin: Meeting the needs of both the cardiologist and the ED physician

Cardiac troponin is the preferred biomarker for defining the acute coronary syndrome and acute myocardial infarction. Currently, the only decision limit formally endorsed with regard to the cardiac troponins is the 99th percentile. This is a "rule-in" criterion, intended to ensure that only persons with the acute coronary syndrome are reviewed. The 99th percentile is an arbitrary cut point and there are many problems associated with its application, including defining a truly healthy population, the difficulty of standardisation of cardiac troponin assays, especially but not only cardiac troponin I, and the effects of age and sex on this parameter. The Emergency Department (ED) screens many more persons for possible acute coronary syndromes than actually have the condition and their needs are best met by a "rule-out" test that enables them to clear their busy departments of the many persons who do not actually have the condition. The needs of the ED are not optimally met using the 99th percentile. The index of individuality for the cardiac troponins is small and significant changes consistent with an acute coronary syndrome can occur without the 99th percentile being exceeded. It appears that the ED may be better served by use of delta troponin changes rather than the 99th percentile, but there are problems with this approach, particularly in persons who present late when troponin release has plateaued. In addition, there are many non-acute coronary syndrome causes for cardiac troponin release. The needs of the cardiologist and the ED physician are so different that it may be inappropriate for both groups to use the same diagnostic criteria for cardiac troponin, and it is of great importance that cardiac troponin measurement be used as only one part of the assessment of the person presenting with possible acute coronary syndrome.

Cardiac and kidney markers for cardiovascular prediction in individuals with chronic kidney disease: the Atherosclerosis Risk in Communities study

OBJECTIVE

Traditional predictors suboptimally predict cardiovascular disease (CVD) in individuals with chronic kidney disease (CKD). This study compared 5 nontraditional cardiac and kidney markers on the improvement of cardiovascular prediction among those with CKD.

APPROACH AND RESULTS

Among 8622 participants aged 52 to 75 years in the Atherosclerosis Risk in Communities (ARIC) Study, cardiac troponin T, N-terminal pro-B-type natriuretic peptide, cystatin C, β2-microglobulin, and β-trace protein were compared for improvement in predicting incident CVD after stratifying by CKD status (940 participants with CKD [kidney dysfunction or albuminuria]). During a median follow-up of 11.9 years, there were 1672 CVD events including coronary disease, stroke, and heart failure (336 cases in CKD). Every marker was independently associated with incident CVD in participants with and without CKD. The adjusted hazard ratios (per 1 SD) were larger for cardiac markers than for kidney markers, particularly in CKD (1.61 [95% confidence interval, 1.43-1.81] for cardiac troponin T, 1.50 [1.34-1.68] for N-terminal pro-B-type natriuretic peptide, and <1.26 for kidney markers). Particularly in CKD group, cardiac markers compared with kidney markers contributed to greater c-statistic increment (0.032-0.036 versus 0.012-0.015 from 0.679 with only conventional predictors in CKD and 0.008-0.011 versus 0.002-0.010 from 0.697 in non-CKD) and categorical net reclassification improvement (0.086-0.127 versus 0.020-0.066 in CKD and 0.057-0.077 versus 0.014-0.048 in non-CKD). The superiority of cardiac markers was largely consistent in individual CVD outcomes.

CONCLUSIONS

A greater improvement in cardiovascular prediction was observed for cardiac markers than for kidney markers in people with CKD. These results suggest that cardiac troponin T and N-terminal pro-B-type natriuretic peptide are useful for better CVD risk classification in this population.

The effect of hemodialysis on cardiac enzyme levels and echocardiographic parameters

BACKGROUND

Cardiac troponins are specific and sensitive markers of myocardial damage. Troponin levels may increase without an obvious active cardiac disease in hemodialysis patients. In this study, we aimed to investigate the effect of a single hemodialysis session on echocardiographic parameters and cardiac enzyme levels, including cTn-I, creatine phosphokinase (CPK), and creatine kinase-MB (CK-MB).

PATIENTS AND METHODS

Forty patients under chronic hemodialysis treatment enrolled in this prospective study. All the patients had a physical examination and underwent echocardiography before and after hemodialysis. cTn-I, CPK and CK-MB levels were also determined before and after hemodialysis in all patients.

RESULTS

Post-dialysis cTn-I levels were significantly higher compared to pre-dialysis levels (p = 0.03). cTn-I levels increased in 26 patients, did not change in 1 patient and decreased in 13 patients after hemodialysis when compared to the values determined before hemodialysis. There was no significant increase in CPK and CK-MB levels after dialysis. Statistically significant changes were detected in the end-systolic diameter of the left ventricle, end-diastolic diameter of left ventricle, ejection fraction, diameter of the left atrium, diameter of the right atrium, pulmonary artery pressure and end-diastolic diameter of the right ventricle. However, there was no significant relation between these echocardiographic changes and ultrafiltration volume, blood flow rate, age, and gender.

CONCLUSIONS

Hemodialysis leads to an increase in cTnI levels. However, the effect of increased cTnI levels on survival rates in hemodialysis patients with underlying coronary artery disease has not yet been determined. Prospective multi-center studies with large sample size are required to clarify this issue.

Independent value of cardiac troponin T and left ventricular global longitudinal strain in predicting all-cause mortality among stable hemodialysis patients with preserved left ventricular ejection fraction

Using a speckle-tracking echocardiography (STE), we recently demonstrated that a left ventricular (LV) global longitudinal strain (GLS) ≥ -15% and the serum cardiac troponin T (cTnT) concentration are associated with mortality in stable hemodialysis patients with preserved LV ejection fraction (LVEF). In this study, we explored the relationship between cTnT and echocardiographic parameters and evaluated whether the prognostic value provided by cTnT is independent of a GLS ≥ -15% and vice versa. Eighty-eight stable hemodialysis patients with preserved LVEF were followed for 31 months. STE studies and measurements of cTnT were performed at baseline. CTnT concentration had a modest correlation with GLS (rs = 0.44; P < 0.001) but had a weak or nonsignificant correlation with other echocardiographic parameters. Adjusting for clinical parameters, hazard ratios for each increase of 0.01 ng/mL in cTnT, and a GLS ≥ -15% on mortality were 1.13 (P = 0.009) and 3.09 (P = 0.03) without significant interaction between cTnT and GLS ≥ -15%. In addition, an increased cTnT concentration, a GLS ≥ -15%, or their combination showed significant additional predictive value for mortality when included in models consisting of clinical parameters. Therefore, both cTnT and a GLS ≥ -15% are independent predictors of mortality and are useful for risk stratification.

Cardiac and inflammatory biomarkers and in-hospital mortality in older medical patients

OBJECTIVES

Increasing evidence has mounted in recent years on the potential prognostic role of biomarkers out of cardiac-specific medical settings. We aimed to test whether cardiac and inflammatory biomarkers are independently associated with in-hospital mortality in older unselected medical inpatients undergoing standardized multidimensional evaluation.

DESIGN

Observational study conducted in a metropolitan university-teaching hospital. A standardized, multidimensional analysis was carried out on all patients by using medical and hospital discharge documentation and interview results integrated with information collected from family members or caregivers.

PARTICIPANTS AND SETTING

Patients older than 65 years consecutively admitted to the acute geriatric ward and to 2 acute medical wards of the hospital.

RESULTS

Male sex; low systolic blood pressure; APACHE score; functional impairment in activities of daily living (ADLs), instrumental ADLs, and Short Physical Performance Battery (SPPB); cognitive impairment; malnutrition; low albumin values; and elevated values of inflammatory and cardiac biomarkers were significantly associated with in-hospital mortality at univariate analysis. After multivariate analysis, male sex, low systolic blood pressure values at entry, severe cognitive impairment, and low functional performance measured by the SPPB resulted to be independently associated with in-hospital mortality.

CONCLUSIONS

The main finding of the present study is that these biomarkers, although associated with in-hospital mortality, do not have independent predictive significance when a comprehensive and multidimensional evaluation is conducted. The main clinical implication is that our findings should discourage the indiscriminate recourse to measurement of cardiac and inflammatory biomarkers, at least in older medical inpatients, thereby reducing a patient's hospital cost and potentially minimizing further unnecessary diagnostic procedures.

Diastolic dysfunction and high levels of new cardiac biomarkers as risk factors for cardiovascular events and mortality in hemodialysis patients

BACKGROUND/AIMS

Cardiovascular events (CVEs) are the most frequent cause of death in hemodialysis (HD). We aim to determine cardiovascular and mortality risk factors.

METHODS

A historical cohort study was made of 211 prevalent HD patients [73 (60-80) years, 58% males] between 2005 and 2012. Demographic, laboratory test and echocardiographic values were recorded. During follow-up, CVEs and mortality were documented and analyzed.

RESULTS

94 patients suffered a CVE. Age, history of cardiovascular disease (CVD), peripheral vascular disease, cardiac markers, systolic and diastolic dysfunction (DD) were associated to CVEs. Low albumin (RR 0.414, p = 0.002), DD (1.876, p = 0.038) and previous CVD (3.723, p < 0.001) were identified as independent predictors of CVEs. 98 patients died. Age, a history of CVD, peripheral vascular disease, cardiac markers, DD, dialysis vintage, and a vascular access different from autologous fistulae were associated to mortality. Low albumin (RR 0.499, p = 0.046), DD (RR 2.414, p = 0.017) and a vascular access different from autologous fistulae (RR 2.058, p = 0.034) were independent predictors of mortality.

CONCLUSIONS

DD is an emergent risk factor for death and CVEs in dialysis. Low albumin is also a predictor for CVE. Non-autologous fistulae and low albumin are predictors for death. Nt-proBNP and hsTnT offer good information for identifying high-risk patients, but they do not predict events independently as they are only cardiac damage markers.

Cardiorenal syndrome type 4: a review

There is a bidirectional and complex relationship between the heart and kidneys. This interaction is physical, chemical as well as biological and is also reflected in a strong connection between renal and cardiovascular diseases. Cardiorenal syndrome type 4 (CRS type 4) is characterized by primary chronic kidney disease (CKD) leading to an impairment of cardiac function, with ventricular hypertrophy, diastolic dysfunction, and/or increased risk of adverse cardiovascular events. The incidence of CKD is increasing, and CRS type 4 is becoming a major public health problem associated with a high morbidity and mortality. In this study, we briefly review the epidemiology and pathophysiology of CRS type 4, the role of biomarkers in its early identification, and its management.

Persistently elevated troponin I in paracetamol hepatotoxicity: association with liver injury, organ failure, and outcome

CONTEXT

An elevated troponin I (TnI) is associated with a poorer prognosis during critical illness.

OBJECTIVE

Our aims were to determine whether significant paracetamol-induced hepatotoxicity was associated with an elevated TnI; if this elevation was persistent and was associated with worse clinical outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, the requirement for orthotopic liver transplantation (OLT) or death and/or the development of multiorgan failure (MOF) was evaluated for 48 consecutive patients admitted to the Royal Infirmary of Edinburgh (a university tertiary referral centre) with acute liver injury or acute liver failure secondary to paracetamol overdose.

RESULTS

TnI was elevated (≥ 0.05 ng/L) in 13/48 patients (27%). This appeared to be sustained for at least 6 days which has not been shown previously in the context of Acute Liver Injury (ALI). Elevated TnI was strongly associated with MOF, with the requirement for inotropic support being the strongest predictor (p = 0.003, OR 9.00, 95% CI 2.13-37.98). TnI elevations also correlated strongly with Acute Physiology and Chronic Health Evaluation (APACHE) II scores (p = 0.0006, r = 0.482, 95% CI 0.22-0.68) and with interleukin 6 (IL-6) levels (p = 0.0001, r = 0.55, 95% CI 0.29-0.73). Although a raised TnI was associated with a markedly increased risk of death or orthotopic liver transplant (p = 0.005, OR 7.73, 95% CI 1.87-32.05) on univariate analysis, this was primarily seen in the context of MOF (SOFA score p = 0.003, OR 1.23, 95% CI 1.07-1.41) and was not an independent predictor of death. There was no correlation between TnI or outcome with other cardiac biomarkers and markers of cardiovascular risk.

DISCUSSION AND CONCLUSION

An elevated TnI in the context of acute liver injury or liver failure following paracetamol overdose is associated with a significantly worse patient outcome but it is not an independent prognostic factor. Further studies should be undertaken to investigate the mechanism behind this elevated troponin association.

Effects of zinc supplement on plasma homocysteine level in end-stage renal disease patients: a double-blind randomized clinical trial

Increased homocysteine (hCys) level is an independent risk factor for cardiovascular complications in end-stage renal disease (ESRD) patients. The aim of this study was to evaluate effect of zinc (Zn) supplement on serum hCys level in ESRD patients. One hundred ESRD patients with Zn deficiency were enrolled in this double-blind randomized clinical trial. They were randomly subdivided into two groups and supplemented with Zn (Zn group) or placebo (control group) for 6 weeks. Fasting plasma hCys and Zn levels were measured before and at 43rd days after the start of the study. Serum Zn levels increased significantly (p < 0.0001), in Zn-treated group in comparison to placebo-treated group. In the Zn-treated group, serum hCys levels reduced significantly (p < 0.0001), compared to placebo group (p > 0.05). There was a significant (p < 0.0001) reduction of mean percentage of hCys in Zn-treated group compared to the placebo group. Our study showed that Zn supplementation decreases serum hCys levels in ESRD patients with Zn deficiency.

Sensible use of high-sensitivity troponin assays

The first intracellular Ca(2+)-sensor protein to be described was the troponin complex. Only later it was -discovered that cardiac-specific isoforms of troponin I (cTnI) and troponin T (cTnT) exist, and nowadays, measurement of cardiac troponins is a corner stone in the diagnosis of patients with acute coronary syndrome (ACS). High-sensitivity (hs-) assays have been developed that can record slightly elevated plasma concentrations of cardiac troponins as early as 3 h after onset of clinical symptoms. International guidelines defined a diagnostic cut-off at cardiac troponin levels corresponding to the 99th percentile of a healthy reference population and require that hs-assays measure this concentration with an interassay coefficient of variation ≤10%. This review provides an overview of the diagnostic and prognostic use of cardiac troponins.

Sensitive troponins--which suits better for hemodialysis patients? Associated factors and prediction of mortality

BACKGROUND

In 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.

METHODS

In 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.

RESULTS

In 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.

CONCLUSION

In 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.