***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Cardiac troponin T ( cTnT ) is a highly sensitive and specific marker of myocardial damage . In sera from patients with end-stage renal disease , cTnT may be elevated without other signs of acute myocardial injury . It has been shown that elevated cTnT in haemodialysis patients is associated with poor prognostic outcome . The aim of the present study was to test the hypothesis that elevated cTnT in a single serum sample from peritoneal dialysis ( PD ) patients is of prognostic importance . METHODS Blood sample s were taken from 26 r and omly selected PD patients without signs of acute myocardial ischaemia . Sera were analysed for : cTnT with the second generation TnT ELISA on ES 300 ; cardiac troponin I ( cTnI ) with Opus Plus ; and for creatine kinase-MB ( CKMB ) mass and C-reactive protein ( CRP ) . After 4 years , clinical outcomes were evaluated by chart review . The influence on survival was tested with Kaplan-Meier analysis and Cox 's proportional regression analysis . RESULTS Concentrations of cTnT > /=0.04 micro g/l and CRP > /=10 mg/l were strong predictors of all-cause mortality in univariate analysis . Twelve out of 14 patients with cTnT > /=0.04 micro g/l died compared with three out of 12 with cTnT < 0.04 micro g/l . Other factors that influenced survival were age and the presence of ischaemic heart disease ( IHD ) . There was a significant positive correlation between cTnT and CRP , and between cTnT and age . Cardiac troponin T was an independent predictor compared with age but not compared with CRP and IHD . Neither cTnI nor CKMB mass concentrations were related to survival . CONCLUSION Elevated serum concentrations of cTnT significantly predicted poor outcome and there was a correlation between cTnT and CRP concentrations in sample s from PD patients . Cardiac troponin I and CKMB mass had no prognostic value BACKGROUND Cardiac troponin T ( cTnT ) is a subunit of the cardiac actin-myosin complex , which leaks into the circulation when myocardial necrosis is present . Detection of cTnT is associated with a poor outcome in patients with unstable angina , and is a useful tool for risk stratification . The value of cTnT determination in patients with renal failure has been question ed , and the specificity of cTnT in this particular group has not been established . METHODS In the present study , 94 patients at a single centre were followed prospect ively after three determinations of cTNT , at 1-month intervals . The outcome after 12 months was chosen as the end-point . cTnT was measured using both a quantitative chemiluminiscence immunoassay and a qualitative rapid bedside immunoassay on a test strip . The maximum of three measurements was used and was correlated with different parameters and outcome . The following statistical tests were performed : Kaplan-Meier analysis , Cox 's proportional regression analysis for measuring survival and logistic regression for analysing factors influencing cTnT. RESULTS Forty seven of the 94 patients had a positive cTnT by test strip defined as > 0.10 ng/ml . Twenty four patients died in the follow-up period ( 14 from cardiovascular causes ) . Twenty of the 24 non-survivors had an increased cTnT by test strip and 23 had increased cTnT by laboratory immunoassay . The outcome analysed by a Cox 's proportional regression analysis showed that the factors which influenced survival significantly were cTnT , the presence of ischaemic heart disease , C-reactive protein ( CRP ) and prealbumin . A logistic multivariate analysis revealed that age and CRP significantly influenced cTnT. A good correlation was found between cTnT determined by test strip and in the laboratory . CONCLUSION cTnT is elevated in a large number of patients on regular haemodialysis and is a significant independent predictor of outcome . Increased cTnT is significantly predicted by age and CRP BACKGROUND The diagnosis of myocardial necrosis in patients with chronic renal failure is often difficult because biochemical markers of cardiac damage such as creatine kinase MB ( CKMB ) and cardiac troponin T ( cTnT ) may be spuriously elevated . Recent small studies also report unexplained elevations in cardiac troponin I ( cTnI ) in chronic renal failure patients undergoing hemodialysis . The relative incidence of elevated cardiac troponins in this population and their relationship to clinical events remain unknown . OBJECTIVE To determine the incidence and prognostic significance of asymptomatic elevations of cTnT and cTnI in patients undergoing hemodialysis for chronic renal failure . DESIGN Prospect i ve cohort study . SETTING University tertiary care teaching hospital . PATIENTS One hundred thirteen patients over 21 years of age undergoing onsite hemodialysis were enrolled between December 1997 and February 1998 . MEASUREMENTS All-cause and cardiovascular mortality , hospitalization for acute myocardial infa rct ion , unstable angina or congestive heart failure , new onset sustained arrhythmia or need for unscheduled emergency hemodialysis  due to volume overload at 30 days and six months . RESULTS The incidence of abnormal results for cTnT , cTnI and CKMB were 42 % , 15 % and 4 % , respectively . Independent predictors of mortality at six months were median age greater than 63 years ( odds ratio 14.3 , 95 % CI 1.5 to 130.3 , P=0.019 ) and positive cTnT ( odds ratio 13.6 , 95 % CI 2.5 to 73.2 , P=0.002 ) . Diabetics were more likely to have positive cTnI and cTnT results than nondiabetics ( P<0.001 and P=0.023 , respectively ) . CONCLUSIONS cTnT is commonly elevated in patients with chronic renal failure even in the absence of acute coronary syndromes . cTnT may be an important independent prognostic marker in patients on hemodialysis for chronic renal failure . While less common , elevations of cTnI are more frequent than CKMB elevations . The basis of these cardiac troponin elevations is unclear . These findings may represent , in part , a sub clinical myocardial injury , an inflammatory response to chronic renal failure or a chronically volume overloaded state OBJECTIVES The aim of the study was investigate the prevalence of abnormal values of cardiac troponin T ( cTnT ) and cardiac troponin I ( cTnI ) in patients with chronic renal failure ( CRF ) and their clinical significance . DESIGN AND METHODS We investigated the concentrations of cTnT and cTnI in 49 CRF patients without heart disease or diabetes . Cardiac TnT values were measured with a second generation immunoassay and cTnI with two immunoassays with different analytical sensitivity . All CRF patients underwent regular clinical follow-up over a 18-month period . RESULTS No patients with CRF had elevated values of cTnI when measured with one assay and only 2 patients displayed minimally elevated values with the second assay . In contrast , 23 CRF patients ( 47 % ) displayed cTnT concentrations elevated above the upper reference limit . The elevated cTnT values observed were below the values detected in acute myocardial infa rct ion and were not associated with adverse cardiac events during follow-up . CONCLUSIONS Mildly elevated cTnT concentrations are common in patients with CRF and do not appear to be associated with adverse coronary events BACKGROUND In patients suffering from end-stage renal failure , cardiac troponin T ( cTnT ) and I ( cTnI ) may be increased in serum without other signs of acute myocardial damage . Whether these increases are specific to myocardial injury or nonspecific is not completely clear . METHODS We investigated time courses of cTnT and cTnI over 1 year and the clinical outcome over 2 years in 59 patients with end-stage renal failure undergoing chronic hemodialysis .  At the start of the study , we divided the patients into two groups , group 1 , without history of cardiac failure , and group 2 , with history of cardiac failure , and looked for differences between the groups in later adverse outcome . cTnT was measured using the Enzymun((R ) ) troponin T assay on an ES 700 analyzer ( Roche ) . cTnI was measured on a Stratus((R ) ) II analyzer ( Dade Behring ) . Creatinine and blood urea nitrogen were measured on a Vitros((R ) ) 950 IRC ( Ortho ) . RESULTS Dialysis acutely increased cTnT ( P : < 0.01 ) and decreased cTnI ( P : < 0.001 ) regardless of the dialysis membrane used . Although statistically not significant , cTnT but not cTnI was increased more frequently in group 2 than in group 1 , in some cases over the whole study period . Five patients ( 8.5 % ) died of cardiac complications within 2 years ; all of them had mostly increased cTnT and , in one or more sample s , increased cTnI. CONCLUSIONS Dialysis alters measured cTnT and cTnI concentrations in serum . In patients suffering from end-stage renal failure , sporadic or persistently increased cTnT and cTnI appear to predict cardiac complications . Because of the effects of the dialysis procedure on troponin values , we recommend that blood be collected before dialysis Background Patients with end-stage renal disease have a high risk of premature death , mainly as the result of cardiovascular disease ( CVD ) , which is not sufficiently explained by the conventional risk factors . We therefore prospect ively investigated total mortality and cardiovascular events in 102 patients on hemodialysis and assessed the prognostic value of baseline disease status and laboratory variables including total homocysteine and cardiac troponin T. Methods and Results Patients were followed for 2 years or until their first event of CVD ( for outcome variable cardiovascular events , n=33 ) or death ( for outcome variable total mortality , n=28 ) . Survival was computed by the Kaplan-Meier method . Cox proportional hazards model was used to determine independent predictors of CVD events or total mortality .  Cardiac troponin T emerged as the most powerful predictor of mortality , result ing in an almost 7-fold risk increase at concentrations > 0.10 ng/mL ( hazard ratio 6.85 , 95 % CI 3.04 to 15.45 ) . Total homocysteine level greater than median was also associated with mortality ( hazard ratio 2.44 , 95 % CI 1.10 to 5.40 ) . These hazard ratios did not change substantially after adjustment for other risk factors . Significant predictors for CVD events were baseline diabetes , cerebrovascular disease , serum glucose , and triglycerides . After adjustment , only glucose and triglycerides remained significantly related to CVD events ( hazard ratio with 95 % CI 1.33 [ 1.12 to 1.57 ] and 1.14 [ 1.04 to 1.26 ] , respectively , for a 1-mmol/L increase in concentration ) . Conclusions We conclude that total homocysteine and particularly cardiac troponin T are important predictors of mortality in patients with end-stage renal disease , whereas other laboratory variables and baseline disease status have less prognostic value In patients with end-stage renal disease ( ESRD ) , the serum concentration of cardiac troponin T ( cTnT ) may be increased without cardiac ischemia . One reason for this unexplained increase could be the extracardiac expression of cTnT. However , truncal skeletal muscle biopsies of five patients with ESRD showed no evidence of the expression of either cTnT mRNA ( reverse transcription-PCR ) or protein ( immunoblot , immunofluorescence ) . We also measured the serum concentration of cTnT  in 97 patients with ESRD . The serum cTnT concentration determined in both first and second generation cTnT assays was significantly lower P < 0.01 in patients with a low cardiac risk than in patients with positive indicators of coronary artery disease . The correlation between cTnT and indicators of coronary artery disease is consistent with the hypothesis that cTnT in the serum of patients with ESRD originates from the heart Diabetic patients undergoing hemodialysis  demonstrate much worse survival rates than do nondiabetic patients undergoing hemodialysis .  To search for risk predictors , a prospect i ve cohort study was performed with 245 hemodialysis patients , including 84 with diabetes mellitus , for 2 yr .  C-reactive protein , troponin T ( TnT ) , total , HDL , LDL , and lipoprotein(a ) cholesterol , apoA2 , apoB , triglyceride , fibrinogen , D-dimer , albumin , and creatinine levels and clinical characteristics at the time of entry were recorded . Survival rates were compared with Kaplan-Meier and Cox regression analyses . Forty-three diabetic patients and 30 nondiabetic patients died . Among diabetic patients , oliguria ( < 200 ml/d ) ( relative risk , 3.24 ; 95 % confidence interval , 1.63 to 6.41 ; P = 0.001 ) , elevated C-reactive 
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The funnel plot showed evidence of publication bias .
Elevated troponin T was also strongly associated with increased cardiac death .
Elevated troponin T ( > 0.1 ng/mL ) identifies a subgroup of ESRD patients who have poor survival and a high risk of cardiac death despite being asymptomatic .
These findings suggest that troponin T is a promising risk stratification tool and may help frame therapeutic decisions .