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

Superiority of high sensitivity cardiac troponin I over NT-proBNP and adiponectin for 7-year mortality in stable patients receiving haemodialysis

Patients on haemodialysis (HD) have high mortality risk, and prognostic values of the major cardiovascular biomarkers cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), and adiponectin should be ascertained over longer follow-up periods using higher-sensitivity assays, which we undertook. In 221 HD patients, levels of high-sensitivity (hs)-cTnI, NT-proBNP, and adiponectin, were measured using high-sensitivity assays, and their associations with all-cause mortality (ACM) and cardiovascular mortality (CVM) were prospectively investigated for 7 years. Higher hs-cTnI and NT-proBNP levels were significant risk factors for ACM and CVM in the Kaplan-Meier analysis. Multivariate Cox proportional hazards analyses in a model including hs-cTnI and NT-proBNP identified log hs-cTnI, but not log NT-proBNP, as an independent risk factor for ACM (HR 2.12, P < 0.02) and CVM (HR 4.48, P < 0.0005). Stepwise analyses identified a high hs-cTnI tertile as a risk factor for ACM (HR 2.31, P < 0.01) and CVM (HR 6.70, P < 0.001). The addition of hs-cTnI to a model including age, CRP, DM, and NT-proBNP significantly improved the discrimination of ACM and CVM each over 7 years. Conclusively, hs-cTnI was superior to NT-proBNP and adiponectin in predicting ACM and CVM over 7 years in HD patients, suggesting the significance of baseline hs-cTnI measurements in long-term management.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Prognostic values of high sensitivity cardiac troponin T and I for long-term mortality in hemodialysis patients

Previous studies using contemporary cardiac troponin (cTn) assays have shown conflicting results in predictability of mortality and major adverse cardiovascular events (MACEs) in hemodialysis patients. We aimed to evaluate the prognostic values of high-sensitivity cTnT (hs-cTnT) and hs-cTnI for long-term mortality and MACEs in asymptomatic chronic hemodialysis patients. 198 asymptomatic patients undergoing regular hemodialysis (age 62.4 ± 14.8 years) were enrolled. Pre-dialysis hs-cTnT and hs-cTnI levels were measured. The study outcomes were long-term all-cause mortality and MACEs. Median values of hs-cTnT and hs-cTnI were 61.1 ng/L (IQR 36.6–102.0) and 18.4 ng/L (IQR 9.5–36.6), respectively. During a median follow-up of 13.5 months, 30 (15.1%) patients developed MACEs, and 20 (10.1%) patients died. The patients in highest quartile of hs-cTnT level (≥ 102 ng/L) had increased risk of long-term mortality (HR 3.34; 95%CI 1.39–8.04, P = 0.005). However, hs-cTnI levels above highest quartile (≥ 36 ng/L) was not significantly associated with increased risk of all-cause mortality. Nevertheless, elevated level of hs-cTnT and hs-cTnI was associated with increased risk of MACEs. We demonstrated that higher level of hs-cTnT, but not hs-cTnI, was associated with increased risk of long-term mortality. Nevertheless, higher level of hs-cTnT and hs-cTnI both were associated with greater risk of long-term MACEs.

Variability of high-sensitivity cardiac troponin T and I in asymptomatic patients receiving hemodialysis

Variation of high-sensitivity cardiac troponin I and T (hs-cTn) during hemodialysis has been observed. Observational studies demonstrated the increased incidence of adverse cardiovascular events after long compared to short interdialytic intervals. Therefore, we aimed to compare variation of hs-cTnI and hs-cTnT before and after hemodialysis and between short and long interdialytic intervals. We enrolled 200 asymptomatic patients receiving regular hemodialysis. The hs-cTnI and hs-cTnT levels were measured before and after hemodialysis on the day after short and long interdialytic intervals. Mean age was 62.3 ± 14.8 years (Male 55.5%). Prevalence of increased hs-cTnI and hs-cTnT was 34.5% and 99.0%, respectively. The median ± interquartile range of hs-cTnT increased significantly after hemodialysis during short and long interdialytic intervals. However, hs-cTnI level did not increase after hemodialysis during short and long intervals. We found that levels of hs-cTnI and T did not differ between short interdialytic and long interdialytic intervals. We demonstrated higher prevalence of elevated hs-cTnT in patients with regular hemodialysis compared to hs-cTnI. The rise of hs-cTnT was observed immediately after hemodialysis but no significant change of hs-cTnI was noted. Accordingly, hs-cTnI may be preferable as a diagnostic marker in patients with suspected acute myocardial infarction than hs-cTnT.

High-sensitivity troponins in dialysis patients: variation and prognostic value

Background

Dialysis patients have a high prevalence of cardiovascular mortality but also elevated cardiac troponins (cTns) even without signs of cardiac ischaemia. The study aims to assess variation and prognostic value of high-sensitivity cTnI and cTnT in prevalent dialysis patients.

Methods

In 198 prevalent haemodialysis (HD) and 78 peritoneal dialysis (PD) patients, 4-monthly serum troponin I and T measurements were obtained. Reference change values (RCVs) were used for variability assessment and competing-risk regression models for survival analyses; maximal follow-up was 50 months.

Results

HD and PD patients had similar troponin levels [median (interquartile range) troponin I: 25 ng/L (14–43) versus 21 ng/L (11–37), troponin T: 70 ng/L (44–129) versus 67 ng/L (43–123)]. Of troponin I and T levels, 42% versus 98% were above the decision level of myocardial infarction. RCVs were +68/−41% (troponin I) and +29/−23% (troponin T). Increased variability of troponins related to higher age, male sex, protein-energy wasting and congestive heart failure, but not ischaemic heart disease or dialysis form. Elevated troponin T, but not troponin I, predicted death after adjusting for confounders.

Conclusions

A large proportion of prevalent dialysis patients without current established or ongoing cardiac events have elevated levels of high-sensitivity cTns. Mortality risk was doubled in patients with persistently high troponin T levels. The large intraindividual variation of cTns suggests that serial measurements and reference change levels may be used to improve diagnostic utility. However, evidence-based recommendations require more data from large studies of dialysis patients with cardiac events.

Ankle-brachial index, arterial stiffness, and biomarkers in the prediction of mortality and outcomes in patients with end-stage kidney disease

BACKGROUND

Although ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) are significant predictors of major adverse cardiovascular event (MACE), their prognostic value in association with biomarkers has not been fully evaluated in patients with end-stage kidney disease (ESKD).

HYPOTHESIS

We hypothesized that ABI/baPWV would provide better prognostic value independent of biomarkers in ESKD patients.

METHODS

This study included 104 ESKD patients treated with maintenance hemodialysis who underwent ABI and baPWV examinations and laboratory tests, including brain-natriuretic peptide, high-sensitive cardiac troponin T (hs-cTnT), and high-sensitive C-reactive protein (hs-CRP). MACE was defined as a composite event of all-cause death, acute coronary syndrome, and stroke.

RESULTS

During a mean follow-up of 3.6 ± 1.7 years, a total of 51 MACE were observed. The independent factors associated with MACE were age >75 years (adjusted hazard ratio [HR], 2.15; P < .05), abnormal ABI (adjusted HR, 2.01; P < .05), left ventricular ejection fraction (LVEF) <50% (adjusted HR, 3.33; P < .001), the upper tertile of hs-cTnT (adjusted HR, 2.77; P < .05), and hs-CRP (HR, 1.96; P < .05). However, baPWV did not remain as an independent predictor of MACE in the entire cohort and also in patients without abnormal ABI. The combination of predictors improves the predictive value of MACE, providing increased HR with 4.00 for abnormal ABI + hs-CRP, 4.42 for abnormal ABI + hs-cTnT, and 7.04 for abnormal ABI + LVEF <50% (all P < .001).

CONCLUSION

Abnormal ABI is a robust predictor of MACE independent of biomarkers and their combination provides better risk stratification compared with a single predictor in ESKD patients.

High-sensitive cardiac troponin T: a biomarker of left-ventricular diastolic dysfunction in hemodialysis patients

OBJECTIVE

To identify the relationship between serum high-sensitive cardiac troponin T (hs-cTnT) and left ventricular diastolic dysfunction (LVDD) among maintenance hemodialysis patients and to further explore the value of hs-cTnT in evaluating and predicting LVDD in this special group of patients.

METHODS

In a cross-sectional study, 152 dialysis patients with end-stage renal disease (ESRD) underwent Hs-cTnT measurement using the high sensitivity assay. Echocardiography measurements were carried out according to the American Society of Echocardiography recommendations and E/E' > 15 or E' < 7 cm/s was defined as diastolic dysfunction. Demographic, biochemical, and echocardiographic values of left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), left atrial diameter, early/late peak velocities ratio (E/A), early peak diastolic annular velocity (E') and E/E' were compared across quartiles of hs-cTnT. The association of plasma hs-cTnT concentrations with echocardiographic parameters was analyzed by Spearman's correlation. The relationship between serum hs-cTnT and LVDD parameters of E/E' and E' was analyzed using multivariate regression analysis, and the value of hs-cTnT on assessing LVDD was evaluated by receiver-operating characteristic (ROC) curves.

RESULTS

The median value of hs-cTnT was 45 pg/ml (range 28-73). All patients had detectable hs-cTnT, while 88% had greater hs-cTnT than the 99th percentile of the general population (14 pg/ml). Serum hs-cTnT values showed a significantly positive correlation with E/E' (r = 0.739, p < 0.001) and LVMI (r = 0.608, p < 0.001), but showed a negative correlation with E' (r = - 0.554, p < 0.001). Serum hs-cTnT was not associated with LV systolic dysfunction. The associations of hs-cTnT with E/E' and E' persisted after multivariate adjustment for LVMI and comorbidities. In logistic multiple regression analysis, compared with the lowest quartile of hs-cTnT, the highest two quartiles were approximately 5 and 11 times more likely to have E/E' > 15 and 7 and 17 times more likely to have E' < 7 cm/s. The area under the ROC curve for hs-cTnT evaluating E/E' > 15 was 0.847 and evaluating E' < 7 cm/s was 0.799, which denoted a moderate accuracy.

CONCLUSIONS

Our studies suggest that serum hs-cTnT may serve as a biomarker of LVDD in hemodialysis patients.

Cardiac Troponins and Their Prognostic Importance in Patients with Suspected Acute Coronary Syndrome and Renal Dysfunction

BACKGROUND

Cardiac troponin (cTn) is important for risk assessment in patients with suspected acute coronary syndrome (ACS). cTn concentrations may, however, be affected by renal dysfunction, and the clinical importance of this interrelation is not well established. We investigated the association between cTnT and cTnI (measured with conventional assays and a more sensitive assay) with the estimated glomerular filtration rate (eGFR) and also assessed the ability of cTn to predict the 1-year all-cause mortality.

METHODS

This retrospective registry-based study used data from 309454 admissions to Swedish coronary care units. cTn associations with eGFR and mortality were assessed using different regression models and by calculating multivariable-adjusted c-statistics.

RESULTS

cTnT concentrations exhibited stronger associations with eGFR than cTnI concentrations (conventional cTnT assay: β = −0.113; more sensitive cTnT assay: β= −0.186; pooled conventional cTnI assays: β = −0.098). Overall, cTnT provided greater prognostic accuracy than cTnI. This was most evident in non-ACS patients with normal or mildly reduced eGFR when using the more sensitive assay. Despite higher mortality rates, no consistent increases in the c-statistics of cTn were seen with severely reduced eGFR irrespective of the presence of ACS or non-ACS.

CONCLUSIONS

cTnT concentrations exhibited stronger associations with reduced eGFR than cTnI concentrations in patients admitted because of suspected ACS. cTnT, particularly when measured using the more sensitive assay, also tended to be a stronger prognosticator. However, the relative significance of the obtained results must be considered in the context of the severity of renal dysfunction and whether ACS is present.

Interaction of Soluble CXC Ligand 16 and Cardiac Injury Markers in Hemodialysis Patients

BACKGROUND

Recent data suggest that there is a pathogenic role for CXC ligand 16 (CXCL16) in cardiovascular diseases. Little is known about circulating CXCL16 in patients with kidney dysfunction. We explored the relationships of plasma CXCL16 with cardiac injury markers in a group of dialysis patients.

METHODS

Plasma CXCL16 and C-reactive protein (CRP) were measured in 366 patients who were on maintenance hemodialysis. Cardiac injury was evaluated via measurements of the circulating B-type natriuretic peptide (BNP), N-terminal prohormone of brain natriuretic peptide (NT proBNP), Troponin I (TnI), and Troponin T (TnT). Sixty healthy subjects who were frequency matched with the patients on the basis of age and gender were recruited as healthy controls.

RESULTS

The mean age of the patients was 52.5 ± 12.1 years and 56.3% were male. Circulating CXCL16 was significantly higher in the patients than in the controls (patients vs.

CONTROLS

477.3 (367.0-647.1) pg/mL vs. 229.5 (203.8-254.5) pg/mL; p < 0.001). The log-transformed (log-) CXCL16 level was correlated with all 4 cardiac markers (log-BNP, log-NTproBNP, log-TnI, and log-TnT) with high levels of significance (all p < 0.001), even after extensive controls for the covariates. In contrast, CRP was correlated only with BNP (marginally) and NT proBNP and was not correlated with troponins.

CONCLUSION

We showed, for the first time, highly significant relationships of circulating CXCL16 level with cardiac injury markers in dialysis patients. Our data suggest that circulating CXCL16 is possibly involved in the pathological process of cardiovascular damage in dialysis patients and may serve as a therapeutic target for cardiac protection in these patients.

What to do when you question cardiac troponin values

High-sensitivity cardiac troponin assays enable cardiac troponin measurement with a high degree of analytical sensitivity and a low level of analytical imprecision at the low measuring range. One of the most important advantages of these new assays is that they allow novel, more rapid approaches for ruling in or ruling out acute myocardial infarctions. The increase in the early diagnostic sensitivity of high-sensitivity cardiac troponin assays comes at the cost of a reduced acute myocardial infarction specificity of the biomarker, because more patients with other causes of acute or chronic myocardial injury without overt myocardial ischaemia are detected than with previous cardiac troponin assays. Increased troponin concentrations that do not fit with the clinical presentation are seen in the daily routine, mainly as a result of a variety of pathologies, and if tested in the same sample, even discrepancies between high-sensitivity cardiac troponin I and troponin T test results may sometimes be found as well. In addition, analytically false-positive test results occasionally may occur since no assay is perfect. In this review, we summarise the biochemical, pathophysiological and analytical background of the work-up for such a clinical setting.

The relationship of plasma creatinine (as eGFR) and high-sensitivity cardiac troponin and NT-proBNP concentrations in a hospital and community outpatient population

OBJECTIVES

While persons with overt renal failure have a well-described rise in troponin and NT-proBNP, it is less well described what the relationship is between cardiac markers and persons with impaired renal function, not requiring dialysis.

DESIGN & METHODS

We have collected ALL samples referred to our pathology practice over a 24h period and measured hs-cTnI, hs-cTnT, NT-proBNP, calculated the eGFR, and related our measurements to clinical outcomes.

RESULTS

For both men and women, for all of hs-cTnI, hs-cTnT and NT-proBNP, there was a graded response, as renal function worsened, the concentration of the cardiac marker increased.

CONCLUSIONS

There is a graded inverse relationship between eGFR and the concentrations of hs-cTnI, hs-cTnT and NT-proBNP. For women only there appeared to be an increase in mortality at lowest eGFR.

Cardiac biomarkers in dialysis

Cardiovascular disease is the major cause of death, accounting for approximately 40 percent of all-cause mortality in patients receiving either hemodialysis or peritoneal dialysis. Cardiovascular risk stratification is an important aspect of managing dialysis patients as it enables early identification of high-risk patients, so therapeutic interventions can be optimized to lower cardiovascular morbidity and mortality. Biomarkers can detect early stages of cardiac injury so timely intervention can be provided. The B-type natriuretic peptides (Brain Natriuretic peptide [BNP] and N-terminal pro-B-type natriuretic peptide [NT-proBNP]) and troponins have been shown to predict mortality in dialysis patients. Suppression of tumorigenicity 2 (ST2) and galectin-3 are new emerging biomarkers in the field of heart failure in both the general and dialysis populations. This article aims to discuss the current evidence regarding cardiac biomarker use to diagnose myocardial injury and monitor the risk of major adverse cardiovascular events in patients undergoing dialysis.

Overhydration Is a Strong Predictor of Mortality in Peritoneal Dialysis Patients - Independently of Cardiac Failure

Background

Overhydration is a common problem in peritoneal dialysis patients and has been shown to be associated with mortality. However, it still remains unclear whether overhydration per se is predictive of mortality or whether it is mainly a reflection of underlying comorbidities. The purpose of our study was to assess overhydration in peritoneal dialysis patients using bioimpedance spectroscopy and to investigate whether overhydration is an independent predictor of mortality.

Methods

We analyzed and followed 54 peritoneal dialysis patients between June 2008 and December 2014. All patients underwent bioimpedance spectroscopy measurement once and were allocated to normohydrated and overhydrated groups. Overhydration was defined as an absolute overhydration/extracellular volume ratio > 15%. Simultaneously, clinical, echocardiographic and laboratory data were assessed. Heart failure was defined either on echocardiography, as a reduced left ventricular ejection fraction, or clinically according to the New York Heart Association functional classification. Patient survival was documented up until December 31^st 2014. Factors associated with mortality were identified and a multivariable Cox regression model was used to identify independent predictors of mortality.

Results

Apart from higher daily peritoneal ultrafiltration rate and cumulative diuretic dose in overhydrated patients, there were no significant differences between the 2 groups, in particular with respect to gender, body mass index, comorbidity and cardiac medication. Mortality was higher in overhydrated than in euvolemic patients. In the univariate analysis, increased age, overhydration, low diastolic blood pressure, raised troponin and NTproBNP, hypoalbuminemia, heart failure but not CRP were predictive of mortality. After adjustment, only overhydration, increased age and low diastolic blood pressure remained statistically significant in the multivariate analysis.

Conclusions

Overhydration remains an independent predictor of mortality even after adjustment for heart failure in peritoneal dialysis patients and should therefore be actively sought and managed in order to improve survival in this population.

Biomarkers of Cardiovascular Disease and Mortality Risk in Patients with Advanced CKD

BACKGROUND AND OBJECTIVES

The high risk of cardiovascular disease (CVD) and premature death in patients with CKD associates with a plethora of elevated circulating biomarkers that may reflect distinct signaling pathways or simply, are epiphenomena of CKD. We compared the predictive strength of 12 biomarkers analyzed concomitantly in patients with stage 5 CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

From 1994 to 2014, 543 patients with stage 5 CKD (median age =56 years old; 63% men; 199 patients had CVD) took part in our study on malnutrition, inflammation, and CVD in incident dialysis patients. Circulating levels of albumin, ferritin, high-sensitivity C-reactive protein (hsCRP), IGF-1, IL-6, orosomucoid, troponin T (TnT), TNF, soluble intracellular adhesion molecule, soluble vascular cellular adhesion molecule 1 (sVCAM-1), and platelet and white blood cell (WBC) counts were analyzed as predictors of the presence of clinically overt CVD at baseline, protein-energy wasting (PEW), and subsequent all-cause mortality. During follow-up for a median of 28 months, there were 149 deaths, 81 of which were caused by CVD.

RESULTS

Most biomarkers were elevated compared with reference values and--except for albumin, ferritin, and IGF-1-higher in patients with CVD. In receiver operating characteristic analysis, age, IL-6, TnT, hsCRP, and IGF-1 were classifiers of baseline CVD and predictors of all-cause mortality. In addition to age, diabetes mellitus, smoking (for CVD), and PEW, only IL-6, relative risk (RR) 1.10 and 95% confidence interval ([95% CI], 1.02 to 1.19), sVCAM-1 RR 1.09 (95% CI, 1.01 to 1.17), and serum albumin RR 0.89 (95% CI, 0.83 to 0.95) associated with baseline CVD, and only WBC, hazard ratio (HR) 1.94 (95% CI, 1.34 to 2.82), IL-6 HR 1.79 (95% CI, 1.20 to 2.67), and TNF HR 0.65 (95% CI, 0.44 to 0.97) predicted all-cause mortality.

CONCLUSIONS

In addition to age and comorbidities, only IL-6, sVCAM-1, and albumin could-independently of other biomarkers-classify clinical CVD, and only IL-6, WBC, and TNF could-independently of other biomarkers-predict all-cause mortality risk. These data underscore the robustness of IL-6 as a classifier of clinically overt CVD and predictor of all-cause mortality in patients with stage 5 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.