Serum troponin T concentration as a predictor of mortality in hemodialysis and peritoneal dialysis patients

Prediction of mortality among patients with chronic kidney disease: A systematic review

BACKGROUND

Chronic kidney disease (CKD) is a common medical condition that is increasing in prevalence. Existing published evidence has revealed through regression analyses that several clinical characteristics are associated with mortality in CKD patients. However, the predictive accuracies of these risk factors for mortality have not been clearly demonstrated.

AIM

To demonstrate the accuracy of mortality predictive factors in CKD patients by utilizing the area under the receiver operating characteristic (ROC) curve (AUC) analysis.

METHODS

We searched Ovid MEDLINE, EMBASE, and the Cochrane Library for eligible articles through January 2021. Studies were included based on the following criteria: (1) Study nature was observational or conference abstract; (2) Study populations involved patients with non-transplant CKD at any CKD stage severity; and (3) Predictive factors for mortality were presented with AUC analysis and its associated 95% confidence interval (CI). AUC of 0.70-0.79 is considered acceptable, 0.80-0.89 is considered excellent, and more than 0.90 is considered outstanding.

RESULTS

Of 1759 citations, a total of 18 studies (n = 14579) were included in this systematic review. Eight hundred thirty two patients had non-dialysis CKD, and 13747 patients had dialysis-dependent CKD (2160 patients on hemodialysis, 370 patients on peritoneal dialysis, and 11217 patients on non-differentiated dialysis modality). Of 24 mortality predictive factors, none were deemed outstanding for mortality prediction. A total of seven predictive factors [N-terminal pro-brain natriuretic peptide (NT-proBNP), BNP, soluble urokinase plasminogen activator receptor (suPAR), augmentation index, left atrial reservoir strain, C-reactive protein, and systolic pulmonary artery pressure] were identified as excellent. Seventeen predictive factors were in the acceptable range, which we classified into the following subgroups: predictors for the non-dialysis population, echocardiographic factors, comorbidities, and miscellaneous.

CONCLUSION

Several factors were found to predict mortality in CKD patients. Echocardiography is an important tool for mortality prognostication in CKD patients by evaluating left atrial reservoir strain, systolic pulmonary artery pressure, diastolic function, and left ventricular mass index.

Diagnosis and treatment of myocardial infarction in patient with end - stage renal disease on chronic hemodialysis

This review represents different aspects of myocardial infarction in patient with end - stage renal disease on chronic hemodialysis. We discuss difficulties in diagnosis, optimal method of coronary revascularization, timing of hemodialysis session, medical therapy, as well as epidemiology and prognosis. There are no unambiguous answers to these problems because patients with end - stage renal disease were excluded from most of the studies.

Framingham risk score and risk of incident chronic kidney disease: A community-based prospective cohort study

Background

Cardiovascular disease and chronic kidney disease share several common risk factors. The Framingham risk score is hypothesized to predict chronic kidney disease development. We determined if the Framingham risk scoring system can correctly predict incident chronic kidney disease in the general population.

Methods

This study included 9,080 subjects who participated in the Korean Genome and Epidemiology Study between 2001 and 2014 and had normal renal function. The subjects were classified into low- (< 10%), intermediate- (10-20%), and high- (> 20%) risk groups based on baseline Framingham risk scores. The primary endpoint was de novo chronic kidney disease development (estimated glomerular filtration rate [eGFR], < 60 mL/min/1.73 m²).

Results

During a mean follow-up duration of 8.9 ± 4.3 years, 312 (5.3%), 217 (10.8%), and 205 (16.9%) subjects developed chronic kidney disease in the low, intermediate, and high risk groups, respectively (P < 0.001). Multivariable analysis after adjustment for confounding factors showed the hazard ratios for the high- and intermediate risk groups were 2.674 (95% confidence interval [CI], 2.197-3.255) and 1.734 (95% CI, 1.447-2.078), respectively. This association was consistently observed irrespective of proteinuria, age, sex, obesity, or hypertension. The predictive power of this scoring system was lower than that of renal parameters, such as eGFR and proteinuria, but increased when both were included in the prediction model.

Conclusion

The Framingham risk score predicted incident chronic kidney disease and enhanced risk stratification in conjunction with traditional renal parameters in the general population with normal renal function.

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.

Which Biomarker is the Best for Predicting Mortality in Incident Peritoneal Dialysis Patients: NT-ProBNP, Cardiac TnT, or hsCRP?: A Prospective Observational Study

Although numerous previous studies have explored various biomarkers for their ability to predict mortality in end-stage renal disease (ESRD) patients, these studies have been limited by retrospective analyses, mostly prevalent dialysis patients, and the measurement of only 1 or 2 biomarkers. This prospective study was aimed to evaluate the association between 3 biomarkers and mortality in incident 335 ESRD patients starting continuous ambulatory peritoneal dialysis (CAPD) in Korea. According to the baseline NT-proBNP, cTnT, and hsCRP levels, the patients were stratified into tertiles, and cardiovascular (CV) and all-cause mortalities were compared. Additionally, time-dependent ROC curves were constructed, and the net reclassification index (NRI) and integrated discrimination improvement (IDI) of the models with various biomarkers were calculated. We found the upper tertile of NT-proBNP was significantly associated with increased risk of both CV and all-cause mortalities. However, the upper tertile of hsCRP was significantly related only to the high risk of all-cause mortality even after adjustment for age, sex, and white blood cell counts. Moreover, NT-proBNP had the highest predictive power for CV mortality, whereas hsCRP was the best prognostic marker for all-cause mortality among these biomarkers. In conclusions, NT-proBNP is a more significant prognostic factor for CV mortality than cTnT and hsCRP, whereas hsCRP is a more significant predictor than NT-proBNP and cTnT for all-cause mortality in incident peritoneal dialysis patients.

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.

Kidney Function Alters the Relationship between Postoperative Troponin T Level and Death

Cardiac troponin T (cTnT), even at low concentrations, is a risk factor for 30-day mortality in patients undergoing noncardiac surgery, but it is uncertain whether that risk is generalizable to patients with poor kidney function. We, therefore, evaluated the relationship between cTnT concentration and kidney function on the outcome of 30-day mortality in a post hoc analysis of a prospective cohort study of patients undergoing noncardiac surgery. cTnT was measured for 3 days after surgery and considered abnormal if the peak was ≥0.02 ng/ml. Of the included 14,037 patients, 267 (1.9%) patients died within 30 days of surgery. The adjusted hazard ratios for death with an abnormal cTnT concentration were 4.37 (95% confidence intervals [95% CI], 3.21 to 6.22), 6.15 (95% CI, 2.95 to 140.9), 6.30 (95% CI, 3.12 to 21.23), 1.33 (95% CI, 0.56 to 4.85), and 1.46 (95% CI, 0.46 to 9.21) for eGFR≥60, 45 to <60, 30 to <45, 15 to <30, and <15 ml/min per 1.73 m(2) or on dialysis, respectively. Compared with patients with eGFR≥60 ml/min per 1.73 m(2), the adjusted hazard ratio was significantly lower for patients with eGFR=15 to <30 ml/min per 1.73 m(2) (interaction P value=0.02). Redefining abnormal cTnT concentration as ≥0.03 ng/ml or a change of ≥0.02 ng/ml did not alter results. Because the risk associated with postoperative cTnT levels may be different for patients with eGFR<30 ml/min per 1.73 m(2), additional research is required to determine how to interpret perioperative cTnT values for patients with low kidney function.

Superior predictive value for NTproBNP compared with high sensitivity cTnT in dialysis patients: a pilot prospective observational study

BACKGROUND/AIMS

The clinical utility of the new biomarker, high sensitivity cardiac T troponin (hs-cTnT) is still unclear in dialysis patients. Furthermore, the prognostic value of combining N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and hs-cTnT has not been explored so far. The objective of this pilot study was to determine the utility of hs-cTnT alone versus hs-cTnT in combination with NT-proBNP for predicting death in a stable hemodialysis cohort.

METHODS

A prospective observational pilot study including 98 chronic asymptomatic hemodialysis patients with a follow up period of 24 months was designed. The cut-off values for NT-proBNP and hs-cTnT were calculated using receiver operating characteristic (ROC) analysis, using mortality as an end-point. Based on the cut-off values, the cohort was divided into four groups. Group 1--NT-proBNP < 14275 pg/ml and hs-cTnT < 69.48 ng/l; group 2--NT-proBNP < 14275 pg/ml and hs-cTnT > 69.48 ng/l; group 3--NT-proBNP > 14275 pg/ml and hs-cTnT < 69.48 ng/l; group 4--NT-proBNP > 14275 pg/ml and hs-cTnT > 69.48 ng/l. Survival for each group was determined using the Kaplan-Meier method and Cox regression analysis.

RESULTS

During the follow-up period 16 patients died. According to the ROC curves analysis, the cut-off point for hs-cTnT and for NT-proBNP were 69.43 ng/l (AUC = 0.618; p = 0.04) and 14275 pg/ml (AUC = 0.722; p = 0.003), respectively. In univariate Cox analysis, both hs-cTnT (HR = 3.34; p = 0.016) and NT-proBNP (HR = 5.94; p = 0.01) were predictors of death. In the multivariable Cox proportional hazards model, only NT-pro-BNP levels above the cut-off value remained an independent predictor of all-cause mortality. The combined elevation of both biomarkers did not improve significantly the prognostic value compared with NT-proBNP alone (HR = 6.15 versus HR =4 .78; p = 0.338).

CONCLUSION

NT-pro-BNP is a strong predictor of overall mortality in asymptomatic hemodialysis patients. The addition of hs-cTnT did not improve the prognostic accuracy compared with NT proBNP alone.

Risk score to predict mortality in continuous ambulatory peritoneal dialysis patients

BACKGROUND

Patients with continuous ambulatory peritoneal dialysis (CAPD) have high all-cause mortality risk that varies extensively among different conditions. The objective of this study was to develop and validate risk models to predict the 2-year all-cause mortality risks of CAPD patients.

MATERIAL AND METHODS

A total of 1354 patients who received CAPD treatment > 3 months from a single dialysis centre were enrolled into the study from January 1, 2006 to December 31, 2011 and followed up until June 30, 2013. The dataset was randomly divided into the derivation dataset (2/3, n = 903) and the validation dataset (1/3, n = 451). Baseline information, including demographic characteristics, comorbid conditions and laboratory data, was recorded and included in the models. Risk models were developed using Cox proportional hazards regression. C-statistic, Akaike Information Criterion, Hosmer-Lemeshow χ(2) test and net reclassification improvement (NRI) were performed to evaluate model prediction and validation.

RESULTS

During the entire follow-up period, 175 (19·38%) and 85 (18·85%) patients died in the derivation and validation datasets respectively. A model that included age, diabetes mellitus, hypertension, cardiovascular disease, diastolic blood pressure, serum albumin, serum creatinine, phosphate, haemoglobin and fasting blood glucose demonstrated good discrimination in the derivation and validation datasets to predict 2-year all-cause mortality (C-statistic, 0·790 and 0·759, respectively). In the validation dataset, the above model performed good calibration (χ(2) = 2·08, P = 0·98) and NRI (7·37% compared with model 2, P = 0·05).

CONCLUSIONS

The risk model can accurately predict 2-year all-cause mortality in Chinese CAPD patients and external validation is needed in future.

High-Sensitivity Troponin as a Predictor of Cardiac Events and Mortality in the Stable Dialysis Population

BACKGROUND

High-sensitivity cardiac troponin T (hs-cTnT) is a biomarker used in diagnosing myocardial injury. The clinical utility and the variation of this biomarker over time remain unclear in hemodialysis (HD) and peritoneal dialysis (PD) patients. We sought to determine whether hs-cTnT concentrations were predictive of myocardial infarction (MI) and death and to examine hs-cTnT variability over a 1-year period.

METHODS

A total of 393 nonacute HD and PD patients (70% HD and 30% PD) were followed in a prospective observational study for new MI and death.

RESULTS

Median hs-cTnT was 57 ng/L (interquartile range, 36–101 ng/L) with no observed difference between HD and PD patients (P = 0.11). Incremental increases in mortality (P = 0.024) and MI (P = 0.001) were observed with increasing hs-cTnT quartiles. MI incidence increased significantly across quartiles in both HD and PD patients (P = 0.012 and P = 0.025, respectively), whereas mortality increased only in HD patients (P = 0.015). For every increase of 25 ng/L in hs-cTnT, the unadjusted hazard ratio (HR) was 1.10 for mortality in the whole group (95% CI, 1.04–1.16, P = 0.001) and 1.16 for MI (95% CI, 1.08–1.23, P &lt; 0.001). Adjusted HR for mortality was 1.07 (95% CI, 1.01–1.15, P = 0.04) and 1.14 for MI (95% CI, 1.06–1.22, P &lt; 0.001). Changes in hs-cTnT from baseline concentrations after 1 year were minimal (55 ng/L vs 53 ng/L, P = 0.22) even in patients who had an MI (P = 0.53).

CONCLUSIONS

hs-cTnT appears to have a useful role in predicting MI and death in the dialysis population. Over a 1-year period concentrations remained stable even in patients who sustained a new cardiac event.

Long-gradient separations coupled with selected reaction monitoring for highly sensitive, large scale targeted protein quantification in a single analysis

Long-gradient separations coupled to tandem mass spectrometry (MS) were recently demonstrated to provide a deep proteome coverage for global proteomics; however, such long-gradient separations have not been explored for targeted proteomics. Herein, we investigate the potential performance of the long-gradient separations coupled with selected reaction monitoring (LG-SRM) for targeted protein quantification. Direct comparison of LG-SRM (5 h gradient) and conventional liquid chromatography (LC)-SRM (45 min gradient) showed that the long-gradient separations significantly reduced background interference levels and provided an 8- to 100-fold improvement in limit of quantification (LOQ) for target proteins in human female serum. On the basis of at least one surrogate peptide per protein, an LOQ of 10 ng/mL was achieved for the two spiked proteins in nondepleted human serum. The LG-SRM detection of seven out of eight endogenous plasma proteins expressed at ng/mL or subng/mL levels in clinical patient sera was also demonstrated. A correlation coefficient of >0.99 was observed for the results of LG-SRM and enzyme-linked immunosorbent assay (ELISA) measurements for prostate-specific antigen (PSA) in selected patient sera. Further enhancement of LG-SRM sensitivity was achieved by applying front-end IgY14 immunoaffinity depletion. Besides improved sensitivity, LG-SRM potentially offers much higher multiplexing capacity than conventional LC-SRM due to an increase in average peak widths (~3-fold) for a 300 min gradient compared to a 45 min gradient. Therefore, LG-SRM holds great potential for bridging the gap between global and targeted proteomics due to its advantages in both sensitivity and multiplexing capacity.

Targeted quantification of low ng/mL level proteins in human serum without immunoaffinity depletion

We recently reported an antibody-free targeted protein quantification strategy, termed high-pressure, high-resolution separations with intelligent selection and multiplexing (PRISM), for achieving significantly enhanced sensitivity using selected reaction monitoring (SRM) mass spectrometry. Integrating PRISM with front-end IgY14 immunoaffinity depletion, sensitive detection of targeted proteins at 50-100 pg/mL levels in human blood plasma/serum was demonstrated. However, immunoaffinity depletion is often associated with undesired losses of target proteins of interest. Herein we report further evaluation of PRISM-SRM quantification of low-abundance serum proteins without immunoaffinity depletion. Limits of quantification (LOQ) at low ng/mL levels with a median coefficient of variation (CV) of ∼12% were achieved for proteins spiked into human female serum. PRISM-SRM provided >100-fold improvement in the LOQ when compared to conventional LC-SRM measurements. PRISM-SRM was then applied to measure several low-abundance endogenous serum proteins, including prostate-specific antigen (PSA), in clinical prostate cancer patient sera. PRISM-SRM enabled confident detection of all target endogenous serum proteins except the low pg/mL-level cardiac troponin T. A correlation coefficient >0.99 was observed for PSA between the results from PRISM-SRM and immunoassays. Our results demonstrate that PRISM-SRM can successfully quantify low ng/mL proteins in human plasma or serum without depletion. We anticipate broad applications for PRISM-SRM quantification of low-abundance proteins in candidate biomarker verification and systems biology studies.

Is cardiac biomarkers and left ventricular function affected by chronic kidney disease?

BACKGROUND

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD). These patients may have high level of cardiac troponins in their serum irrelevant to acute coronary syndrome (ACS) that could have profound impact on patient's morbidity and mortality.

OBJECTIVES

The aim of this study was to assess the relation between level of serum creatinine (Cr) and cardiac troponins T and I, and left ventricular (LV) function (as defined by LV ejection fraction) in non-dialysis and non-acute coronary syndrome CKD patients.

MATERIALS AND METHODS

This is a prospective cross sectional study that includes 150 non-dialysis CKD patients without history of ACS in at least 1 month before the beginning of the study. Patients with history of CKD (serum Cr ≥1.5 mg/dl) of more than 6 months were selected. Patients with advanced multi-organ disease (lung disease, liver disease, cerebrovascular disease and peripheral vascular disease) and history of dialysis were excluded from the study. In each patient blood sample was obtained for analyzing serum Cr and cardiac troponin T and I (cTnT and cTnI). Also LV ejection fraction (LVEF) was measured by echocardiography in the same session.

RESULT

There was a positive non-parametric relation between serum Cr and cTnT (p = 0.028). However there were no relation between serum Cr, cTnI (p = 0.57) and LVEF (p = 0.188).

CONCLUSION

In patients with CKD, serum Cr level has an impact on cTnT, but has no impact on cTnI and LVEF.

A more appropriate cardiac troponin T level that can predict outcomes in end-stage renal disease patients with acute coronary syndrome

PURPOSE

Cardiac troponin T (cTnT), a useful marker for diagnosing acute myocardial infarction (AMI) in the general population, is significantly higher than the usual cut-off value in many end-stage renal disease (ESRD) patients without clinically apparent evidence of AMI. The aim of this study was to evaluate the clinical usefulness of cTnT in ESRD patients with acute coronary syndrome (ACS).

MATERIALS AND METHODS

Two hundred eighty-four ESRD patients with ACS were enrolled between March 2002 and February 2008. These patients were followed until death or June 2009. Medical records were reviewed retrospectively. The cut-off value of cTnT for AMI was evaluated using a receiver operating characteristic (ROC) curve. We calculated Kaplan-Meier survival curves, and potential outcome predictors were determined by Cox proportional hazard analysis.

RESULTS

AMIs were diagnosed in 40 patients (14.1%). The area under the curve was 0.98 in the ROC curve (p<0.001; 95% CI, 0.95-1.00). The summation of sensitivity and specificity was highest at the initial cTnT value of 0.35 ng/mL (sensitivity, 0.95; specificity, 0.97). Survival analysis showed a statistically significant difference in all-cause and cardiovascular mortalities for the group with an initial cTnT ≥0.35 ng/mL compared to the other groups. Initial serum cTnT concentration was an independent predictor for mortality.

CONCLUSION

Because ESRD patients with an initial cTnT concentration ≥0.35 ng/mL have a poor prognosis, it is suggested that urgent diagnosis and treatment be indicated in dialysis patients with ACS when the initial cTnT levels are ≥0.35 ng/mL.

How does volume status affect BNP and troponin levels as markers of cardiovascular status in peritoneal dialysis?

Cardiac biomarkers such as brain natriuretic peptide, amino-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac troponin provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic hemodialysis patients, both biomarkers-NT-proBNP and troponin-are elevated despite the absence of cardiac ischemia. The elevation of cardiac biomarkers in chronic hemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. Furthermore, they can serve as tools for volume assessment for optimization of the fluid management aspect of dialysis. However, the association of both these markers in peritoneal dialysis is not clear. Therefore, the authors reviewed the literature to examine the role of these markers in peritoneal dialysis patients both as prognostic indicators as well as tools for volume assessment.

Haemodialysis patients longitudinally assessed by highly sensitive cardiac troponin T and commercial cardiac troponin T and cardiac troponin I assays

Background

Elevated cardiac troponin (cTn) concentrations predict an increased mortality in patients suffering from end-stage renal disease (ESRD). This study compares the performance of a precommercial high-sensitive cTnT assay (hs-cTnT) with two contemporary cTn assays in detecting cTn elevations in ESRD patients during a six-month follow-up.

Methods

Thirty-two ESRD patients were followed for six months, during which cTn concentrations were assessed every two months. Baseline biomarker concentrations were compared with those in a simultaneously measured reference population of 501 healthy subjects.

Results

During follow-up 26 (81%), 32 (100%) and 9 (28%) of the patients showed elevated cTn concentrations according to the current cTnT, the hs-cTnT and the cTnI assays, respectively. The range of concentrations measured in each patient had a median (interquartile range) magnitude of 0.03 μg/L (0.02–0.06), 0.017 μg/L (0.011–0.029) and 0.011 μg/L (0–0.017) according to the aforementioned assays.

Conclusion

According to the hs-cTnT assay, all of the ESRD patients had elevated cTnT concentrations at least once during the follow-up. As elevated cTn concentrations are highly prognostic of adverse events, the use of serial measurements has thus identified additional patients at risk for such events. The fact that we find cTn concentrations to be higher in patients with a history of cardiac disease is in line with this. Additional studies in ESRD patients are needed to investigate the added diagnostic and prognostic value of the very low cTnT concentrations and variations detected only by the hs-cTnT assay.

Prognostic value of elevated cardiac troponin I in ESRD patients with sepsis

BACKGROUND

Elevated cardiac troponin (cTn) levels have been reported to predict adverse cardiovascular outcomes in asymptomatic ESRD patients. However, the prognostic value of elevated cTn levels associated with sepsis in ESRD patients is unknown. Therefore, this study aimed to elucidate the clinical implications of elevated cTnI levels in ESRD patients with sepsis.

METHODS

Of the 305 ESRD patients in whom cTnI was measured between January 2003 and December 2005, sepsis developed in 121 patients during follow-up. Based on cTnI levels at the onset of sepsis, patients were classified as elevated cTnI group (ET, n = 50, >0.2 ng/ml) and lower cTnI group (LT, n = 71, < or =0.2 ng/ml). Study endpoints were short- and long-term mortality. Short-term mortality was defined as death occurring within 90 days after sepsis, and patients who survived during this period were followed till death after 90 days.

RESULTS

Before sepsis, the median concentration of cTnI was 0.05 (0.01-3.59) ng/ml and it was significantly increased to 0.11 (0.01-22.0) ng/ml when sepsis supervened (P < 0.01). Compared to the LT group, the short-term mortality rate was significantly higher in the ET group (P < 0.05). After adjustment for age, diabetes, serum albumin and CRP levels, presence of shock and previous cardiovascular disease history, the ET group had a greater odds ratio of short-term mortality (OR 5.13, P < 0.01). In addition, the Kaplan-Meier plot for long-term survival revealed a significantly higher mortality rate in the ET group. In a multivariate Cox regression analysis, the elevation of cTnI levels was an independent determinant for long-term mortality (HR 5.90, P < 0.01).

CONCLUSION

This study showed that elevated cTnI levels were significantly associated with short- and long-term mortality in ESRD patients with sepsis. Therefore, elevated cTnI levels in these patients should not be overlooked and be followed for adverse outcomes.

Effect of hemodialysis on traditional and innovative cardiac markers

The diagnostic approach to acute coronary syndrome (ACS) is challenging in patients with impaired renal function since most serum biomarkers are commonly increased in this clinical setting. Cardiac troponin T (cTnT), creatine kinase isoenzyme MB (CK MB), myoglobin, and ischemia modified albumin (IMA), were assayed in 45 patients prehemodialysis (pre-HD) and posthemodialysis (post-HD), and results were adjusted for hemoconcentration. The pre-HD values of serum IMA and cTnT were above the respective diagnostic thresholds (IMA<85 K units/L; cTnT <0.03 ng/mL) in six (13%) and 27 (60%) patients undergoing chronic HD, respectively. A significant (105.0 vs. 79.0 K units/L, P<0.0001) and variable (+38%; 95% confidence interval [CI], 12-65%) increase of serum IMA was observed post-HD, whereas the other biomarkers significantly decreased (cTnT: 0.029 vs. 0.044 ng/mL, P=0.016; CK-MB: 2.33 vs. 2.50 microg/L, P<0.0001; myoglobin: 128.1 vs. 148.7 microg/L, P<0.0001). Biomarkers of myocardial injury, especially cTnT and IMA, might be used in HD patients, provided that an appropriate diagnostic interpretation is guarantee, according to individual baseine value, metabolism, and time of sampling. Moreover, IMA might be reliably applied to stratify the long-term risk of these patients, but not for diagnosing an ACS during or immediately post-HD.

Relationships of N-terminal pro-B-natriuretic peptide and cardiac troponin T to left ventricular mass and function and mortality in asymptomatic hemodialysis patients

BACKGROUND

Although the cardiac biomarker troponin T (cTnT) is related strongly to mortality in patients with end-stage renal disease, the independent association of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and cTnT levels in predicting outcomes is unknown. The objective of this study is to determine factors associated with NT-pro-BNP and cTnT and determine whether these levels are associated with mortality.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

Asymptomatic hemodialysis patients (n = 150) in 4 university-affiliated hemodialysis units. EXPOSURE & OUTCOMES: For cross-sectional analysis, echocardiographic variables as exposures and NT-pro-BNP and cTnT levels as outcomes; for longitudinal analysis, association of NT-pro-BNP and cTnT levels as exposures to all-cause and cardiovascular disease mortality as outcomes.

RESULTS

In a multivariate regression analysis, low midwall fractional shortening, a measure of poor systolic function, was an independent correlate of log NT-pro-BNP level (P < 0.01), whereas left ventricular mass index was an independent correlate of cTnT level (P < 0.01). During a median follow-up of 24 months, 46 patients died, 26 of cardiovascular causes. NT-pro-BNP levels had a strong graded relationship with all-cause (hazard ratios [HRs], 1.54, 4.78, and 4.03 for increasing quartiles; P < 0.001) and cardiovascular mortality (HRs, 2.99, 10.95, and 8.54; P < 0.01), whereas cTnT level had a weaker relationship with all-cause (HRs, 1.57, 2.32, and 3.39; P < 0.01) and cardiovascular mortality (HRs, 0.81, 2.12, and 2.14; P = 0.1). The combination of the 2 biomarker levels did not improve the association with all-cause or cardiovascular mortality compared with NT-pro-BNP level alone. NT-pro-BNP level was a marker of mortality even after adjusting for left ventricular mass index and midwall fractional shortening.

LIMITATIONS

Our cohort was predominantly black and of limited sample size.

CONCLUSION

NT-pro-BNP level strongly correlates with left ventricular systolic dysfunction and is associated more strongly with mortality than cTnT level in asymptomatic hemodialysis patients.

Cardiac biomarkers in haemodialysis patients: the prognostic value of amino-terminal pro-B-type natriuretic peptide and cardiac troponin T

Cardiac biomarkers such as amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTNT) provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic haemodialysis patients, both biomarkers - NT-proBNP and cTNT - are elevated despite the absence of cardiac ischaemia. The elevation of cardiac biomarkers in chronic haemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. They provide a useful rationale for the screening of occult cardiac disease and optimization of the dialysis procedure with respect to volume control.

Cardiac troponins I and T in hemodialysis patients without acute coronary syndrome

BACKGROUND

There is a reluctance to use cardiac troponins (cTn) for the monitoring of acute coronary syndrome (ACS) in hemodialysis (HD) patients because renal failure per se is thought to lead to increased cTn levels. The aim of this study was to analyse the proportion of patients with increased cTn levels in HD patients without ACS.

METHODS

cTnI was measured with the AccuTnI(trade mark) from Beckman (cTnI-B) and Troponin I Stat(trade mark) from Dade Behring (cTnI-DB) assays; cTnT was measured with the third generation assay from Roche. The study included 105 HD patients. The clinical outcomes were determined after 2.5 years.

RESULTS

Considering the receiver operator characteristic (ROC) cutoff, the proportion of patients with elevated cTnI-B, cTnI-DB and cTnT levels was respectively 2%, 3% and 27%. The proportion of patients with abnormal cTn values increased when a lower cutoff value was considered, based on the 99th percentile of a reference population with a coefficient of variation of less than 10% (99th percentile-10% CV cutoff). The proportion of patients with elevated values did not differ before and after the HD session. The 2.5 years mortality was associated with increased levels of cTnT but not with increased levels of cTnI.

CONCLUSIONS

When the ROC cutoff is applied, cTnI assays are suitable for the monitoring of ACS in HD patients. cTnT could lead to false positive diagnosis of myocardial infarction, however it is predictive of long-term mortality. The 99th percentile-10% CV cutoff does not seem appropriate in HD patients.

Prognostic value of cardiac troponin T is independent of inflammation, residual renal function, and cardiac hypertrophy and dysfunction in peritoneal dialysis patients

BACKGROUND

We investigated whether cardiac troponin T (cTnT) independently predicted outcome and added prognostic value over other clinical risk predictors in chronic peritoneal dialysis (PD) with end-stage renal disease.

METHODS

Baseline cTnT, echocardiography, indices of dialysis adequacy, and biochemical characteristics were assessed in 238 chronic PD patients who were followed prospectively for 3 years or until death.

RESULTS

Using multivariable Cox regression analysis, cTnT remained predictive of all-cause mortality [hazard ratio 4.43, 95% CI 1.87-10.45, P = 0.001], cardiovascular death (4.12, 1.29-13.17, P = 0.017), noncardiovascular death (8.06, 1.86-35.03, P = 0.005), and fatal and nonfatal cardiovascular events (CVEs) (3.59, 1.48-8.70, P = 0.005) independent of background coronary artery disease, inflammation, residual renal function, left ventricular hypertrophy, and systolic dysfunction. cTnT alone had better predictive value than C-reactive protein (CRP) alone for mortality [area under the ROC curve (AUC) 0.774 vs 0.691; P = 0.089] and first CVE (AUC 0.711 vs 0.593; P = 0.009) at 3 years. Survival models including age, sex, and clinical, biochemical, and echocardiographic characteristics yielded AUCs of 0.813 (95% CI, 0.748-0.877), 0.800 (95% CI, 0.726-0.874), and 0.769 (95% CI, 0.708-0.830), respectively, in relation to all-cause mortality, cardiovascular death, and fatal and nonfatal cardiovascular events. After addition of cTnT, AUCs of the above models increased significantly to 0.832 (95% CI, 0.669-0.894; P = 0.0037), 0.810 (95% CI, 0.739-0.883; P = 0.0036), and 0.780 (95% CI, 0.720-0.840; P = 0.0002), respectively; no AUCs increased when CRP was added.

CONCLUSIONS

cTnT is an independent predictor of long-term mortality, cardiovascular death and events, and noncardiovascular death in PD patients.