Cardiac troponin elevations in chronic renal failure: prevalence and clinical significance

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 infarction 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.     

Cardiac troponins and renal function in nondialysis patients with chronic kidney disease

BACKGROUND: Serum cardiac troponin concentrations are commonly increased in end-stage renal disease (ESRD) in the absence of an acute coronary syndrome (ACS). The data on cardiac troponin I (cTnI) are more variable than those for cardiac troponin T (cTnT). There is little information on cardiac troponin concentrations in patients with chronic kidney disease (CKD) who have not commenced dialysis. METHODS: We studied 222 patients: 56 had stage 3 (moderate CKD); 70 stage 4 (severe CKD); and 96 stage 5 (kidney failure). Patients underwent echocardiography and were followed prospectively for a median of 19 months; all-cause mortality was recorded. RESULTS: Overall, serum cTnT was increased above the 99th percentile reference limit in 43% of all CKD patients studied, compared with 18% for cTnI. Serum cTnT and cTnI concentrations were more commonly increased in the presence of more severe CKD (11 and 6 patients in stage 3, 27 and 8 in stage 4, and 57 and 24 in stage 5 (P < 0.0001 and <0.02, respectively). Among 38 patients with detectable cTnI, 32 had detectable cTnT (r(s) = 0.67; P < 0.0001). There was evidence that decreasing estimated glomerular filtration rate increased the odds of having detectable cTnT (P < 0.001) but not cTnI (P = 0.128). There was no evidence to support an adjusted association of detectable cardiac troponins with increasing left ventricular mass index. Increased cTnT (P = 0.0097), but not cTnI, was associated with decreased survival. CONCLUSIONS: Increased cTnT and cTnI concentrations are relatively common in predialysis CKD patients, in the absence of an ACS, including among those with stage 3 disease. The presence of left ventricular hypertrophy alone does not explain these data. Detectable cTnT was a marker of decreased survival.     

Cardiac troponin T circulates in the free, intact form in patients with kidney failure

BACKGROUND: The clinical significance of the increased concentrations of cardiac troponins observed in patients with end stage renal disease (ESRD) in the absence of an acute coronary syndrome (ACS) is controversial. One proposed explanation is that immunoreactive fragments of cardiac troponin T (cTnT) accumulate in ESRD. We used gel-filtration chromatography (GFC) to ascertain whether fragments of cTnT, which could cross-react in the commercial diagnostic immunoassay (Roche Diagnostics), were the cause of the increased cTnT in the serum of patients with ESRD. METHODS: We subjected sera from ESRD patients (n = 21) receiving dialysis and having increased cTnT concentrations to size-separation GFC. We detected cTnT in the chromatography fractions by use of the same antibodies used in the commercial assay for serum cTnT. RESULTS: In all patients, cTnT immunoreactivity eluted as a major, homogeneous peak in an identical position between the peaks of serum prolactin [relative molecular mass (Mr) 23,000] and albumin (Mr 67,000): the elution pattern of cTnT in samples obtained from ACS patients was identical to that of the ESRD patients. There was no evidence that low-molecular-mass (Mr < 23,000) cTnT fragments were the cause of the increased cTnT in the patients studied. CONCLUSIONS: The form of cTnT observed in the serum of patients with kidney failure and immunoreactive in the diagnostic assay is predominantly the free intact form, as in patients with ACS. Our data are consistent with the view that circulating cTnT in renal failure reflects cardiac pathology.     

Cardiac troponin T and I in end-stage renal failure

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 samples, 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.     

肾移植术后多尿期两种循环补液方式的对比研究

目的比较肾移植术后多尿期两种循环补液方式对患者肾功能、血电解质、血糖水平的影响,探讨更加优化的循环补液方式。方法2010年1月至2012年12月在我中心实施肾移植的132例患者按随机数字表法分成传统治疗组与改进治疗组。传统治疗组循环补液按顺序依次、单瓶、经输液泵输入,改进治疗组术后按循环补液表将所有液体混合配制成离子浓度和渗透压适宜移植肾功能恢复的3L袋溶液,经输液泵输入,循环补充。观察两组患者术前及术后各时间点血肌酐（Cr）、尿素氮（Bun）、电解质、血糖浓度的变化,比较两组患者补液效果。结果两组患者术后各时间点肾功能、电解质比较差异均无统计学意义（P〉0．05）,血糖值在术后4、8、12、16、24、48、72h差异均有统计学意义（P〈0．05）。结论改进循环补液方式,可维持肾移植患者术后多尿期血电解质平衡,有效控制血糖水平;并能解决传统补液方式存在的液体种类多、操作相对繁琐等问题,有效提高护理工作质量与效率。     

Cardiac troponin T predicts long-term outcomes in hemodialysis patients

BACKGROUND: Increased plasma troponin T (cTnT), but not troponin I (cTnI), is frequently observed in end-stage renal failure patients. Although generally considered spurious, we previously reported an associated increased mortality at 12 months. METHODS: We studied long-term outcomes in 244 patients on chronic hemodialysis for up to 34 months, correlating the outcomes to plasma cTnT in routine predialysis samples. In addition, subsequent plasma samples at least 1 year later and within 6 months of data analysis were available in 97 patients and were used to identify patients with increasing plasma cTnT. The endpoints used were death and new or worsening coronary, cerebro-, and peripheral vascular disease and neuropathy. RESULTS: Transplantation occurred more frequently in patients with low initial cTnT: 31%, 13%, and 3% in the groups with cTnT < 0.010, 0.010-0.099, and > or = 0.100 microg/L, respectively. In the same groups, total deaths occurred in 6%, 43%, and 59% and cardiac deaths in 0%, 14%, and 24% of patients. In patients with follow-up samples, the group with increasing cTnT had a significantly increased death (relative risk, 2.0; P = 0.028). The increase was mainly in cardiac and sudden deaths. CONCLUSIONS: Higher plasma cTnT predicts long-term all-cause mortality in hemodialysis patients, even at concentrations < 0.100 microg/L, as does an increasing cTnT concentration over time.     

Cardiac troponin T and creatine kinase MB are not increased in exterior oblique muscle of patients with renal failure

BACKGROUND: Serum cardiac troponin T (cTnT) concentrations may be increased in patients with renal dysfunction without evidence of cardiac damage, as assessed by conventional methods. It has been suggested that these positive measurements result from the expression in skeletal muscle of fetal isoforms of cTnT, which are detected by the cTnT immunoassay. METHODS: Skeletal muscle (exterior oblique) biopsies were taken from healthy living kidney donors (n = 5) and transplant recipients (n = 19). The amounts of cTnT and creatine kinase (CK) isoenzymes in skeletal muscle of healthy controls were compared with those in patients with renal failure (Wilcoxon-Mann-Whitney test). cTnT was measured quantitatively by a second-generation assay, with a limit of detection of 1 microg/g of protein, and qualitatively by immunohistochemistry and immunoblotting. CK-MB was measured by quantitative electrophoresis. RESULTS: Minute quantities of cTnT were detected in 2 of the 5 (40%) control samples and 9 of the 19 (47%) renal failure samples, respectively, at mean concentrations of <5 microg/g of protein for both subject groups. This was <1/6000th that found in heart muscle. There was no significant difference in cTnT or CK-MB content in skeletal muscle between healthy controls and patients with renal failure. Increased serum cTnT did not predict detectable cTnT in skeletal muscle. cTnT was not detected qualitatively by immunoblotting or immunohistochemistry in any skeletal muscle samples. CONCLUSIONS: Uremia does not affect the content of cTnT or CK-MB in exterior oblique muscle, suggesting that cTnT detected in serum from patients with renal failure does not originate from skeletal muscle.     

Evaluation of pregnancy-associated plasma protein A as a prognostic indicator in acute coronary syndrome patients

BACKGROUND: Higher circulating concentrations of pregnancy-associated plasma protein A (PAPP-A), a potential proatherosclerotic metalloproteinase, have been associated with increased risk for acute coronary syndrome (ACS). Our goal was to determine the ability of circulating concentrations of PAPP-A to predict adverse events in patients presenting to the Emergency Department (ED) with symptoms of ACS. METHODS: A total of 346 patients with symptoms of ACS were included in the study. Serum samples obtained immediately after enrollment were analyzed for PAPP-A and cardiac troponin T (cTnT). The occurrence of adverse events during a 30-day follow-up period was recorded, and receiver-operating characteristic (ROC) curve analysis was performed to evaluate the prognostic characteristics of PAPP-A and cTnT. RESULTS: A total of 33 (9.5 %) patients developed adverse events during the follow up period. At a cut-off concentration of 0.22 mIU/l, PAPP-A was a predictor of adverse events with a sensitivity and specificity (95% C.I.) of 66.7% (48.2-82.0) and 51.1% (45.4-56.8), respectively. The sensitivity and specificity of cTnT were 51.5% (33.6-69.2) and 82.1% (77.4-86.2), respectively, using a 0.01-ng/ml cut-off value, which was obtained using ROC analysis. CONCLUSIONS: PAPP-A appears to be a modest predictor of adverse events in patients presenting to the ED with ACS symptoms, being inferior to cTnT in predicting adverse events in an ED setting. PAPP-A appears to be as sensitive as cTnT, but it is less specific.     

Risk stratification using serum concentrations of cardiac troponin T in patients with end-stage renal disease on chronic maintenance dialysis

BACKGROUND: It has been recently suggested that cardiac troponin T (cTnT) may be more sensitive than troponin I (cTnI) for subclinical myocardial cell injury in patients on chronic dialysis. METHODS: We prospectively compared the predictive value of cTnT with cTnI, atrial (ANP) and brain natriuretic peptide (BNP) in 100 consecutive outpatients on chronic dialysis without acute coronary syndromes over a period of 3 months, and assessed whether the combination of cTnT with clinical information including age, duration of dialysis, and medical histories was useful for risk stratification of these patients. During the 2-year follow-up period, 19 patients died, mostly due to cardiac causes (53%). RESULTS: The area under the receiver operator characteristic (ROC) curve for the cTnT as predictor of both overall and cardiac death was significantly greater than the area under the cTnI curve (p < 0.0001 and p = 0.01), the BNP curve (p < 0.001 and p < 0.01) or the ANP curve (p < 0.0001 and p < 0.005). In a stepwise multivariate Cox regression analysis, only cTnT (p < 0.05 and p < 0.01) and a history of heart failure requiring hospitalization (p < 0.05 and p < 0.005) were independent predictors of both all cause and cardiac mortality. Using parameters of cTnT > or =0.1 microg/l and/or history of heart failure, the overall and cardiac mortality rate for the low risk group (n=66) were 4.5% and 1.5%, respectively, 40% and 16% for the intermediate risk group (n=25), and 67% and 56% for the high risk group (n=9). CONCLUSION: cTnT concentrations offer a higher prognostic accuracy than cTnI, ANP and BNP in patients on chronic dialysis. The combination of elevated cTnT and a history of heart failure may be a highly effective means of risk stratification of these patients.     

分层强化健康教育模式在肾移植康复期患者中实施的效果评价

目的 旨在了解分阶段健康教育模式对肾移植康复期患者的影响,深化优质护理内涵。方法 选择2010年12月～2011年9月收治的96例肾移植康复期的患者作为对照组,给予传统健康教育;选择2011年10月～2012年7月收治的99例肾移植康复期的患者作为观察组,根据移植术后时间,分为术后3个月、3-6个月、6个月以上三个阶段,根据不同阶段的疾病特点有针对性的进行健康教育：第一阶段（术后3个月）,着重建立良好的医护患沟通关系,给予正确用药指导,指导规律运动,从费力较少的运动开始,循序渐进。第二阶段（术后3-6个月）,根据不同性别、年龄、文化程度的患者所产生的心理问题给予针对性的心理护理。比如男性及年轻患者易于接受宣教,可以集中进行健康指导,但是女性和年龄较大的患者需要在日常生活中予以实践指导与关心,即“宣教于平时”;同时该阶段是肾移植后存活最关键的时期,因此要告知患者排斥反应现象,如遇发热、移植肾区痛、体重突然增加、血压升高、尿量减少等要及时就医,提高肾移植患者自我监护能力。第三阶段（术后6个月以上）,着重于健康生活方式的指导,主要包括坚持服药,定期复诊,自我监护,调节身心等方面。分别观察两组不同阶段的患者依从性、并发症的发生率以及满意度的变化。结果 观察组三个阶段的患者依从性、满意度明显优于对照组(P<0.05);观察组三个阶段的患者肾移植术后无近期并发症发生,对照组出现17例不同程度的并发症。结论 对肾移植术后康复患者实施分阶段、全程式健康教育作为一种优质护理服务的延伸,提高了护士对健康教育的重视程度以及健康教育的时效性,改善了患者疾病自我管理行为和疾病照护的结局。     

Comparison of plasma cardiac troponins T and I in chronically hemodialyzed patients in relation to cardiac status and age.

Cardiac troponins (cTnT and cTnI) are useful tools for risk stratification in patients with unstable angina. However, their value in patients with renal failure has been questioned. In this study, we determined cTnT and cTnI at 3-month intervals during 9 months in 97 chronic renal failure (CRF) patients treated with hemodialysis. cTnT was measured using a third generation immunoassay and cTnI by fluorimetric immunoassay with a detection limit similar to that of cTnT (0.01 microg/l). In the renal patients without coronary heart disease (CHD(-) group), cTnT was more frequently elevated above cut-off for acute myocardial infarction (AMI) (up to 21.6%) than cTnI (no patient). In the absence of CHD, cTnT levels were positively correlated to age, and more than half of the CHD(-) patients aged over 60 years had cTnT levels above the upper reference limit (URL) of 0.04 microg/l (0.059+/-0.042 microg/l). cTnI increased with age in parallel to cTnT but mean levels did not exceed the URL of 0.08 microg/l in the CHD(-) patients aged over 60 years (0.036+/-0.031 microg/l). In the patients with documented cardiac events (CHD(+)) we found higher troponin levels than in the CHD(-) patients of the corresponding age, but for cTnl the differences between CHD(+) and CHD(-) patients were significant in the patients aged < or =60 years only (0.049+/-0.054 vs. 0.019+/-0.018 microg/l, p<0.05). For cTnT, the differences between patients with and without coronary events also tended to be less important in the eldest patients. There was a significant correlation between cTnI and cTnT levels in the CHD(-) and in the CHD(+) groups. Changes in the plasma levels of cardiac troponins are common in hemodialysis patients in the absence of CHD, and advanced age appears to amplify these changes. The reason could be that most hemodialysis patients with advanced age have subclinical lesions and demonstrate release characteristics of troponins that compare to those in patients with symptomatic coronary events. Therefore, it will be important to analyze troponin elevations above the URL or above the cut-off concentration for AMI in asymptomatic renal patients in relation to prognosis.     

Evaluation and risk stratification of acute coronary syndromes using a low cut-off level of cardiac troponin T, combined with CK-MB mass determination

OBJECTIVES: To study the usefulness of combined cardiac Troponin T (cTnT) and CK-MB mass determinations in risk stratification of acute coronary syndromes. DESIGN AND METHODS: Blood samples for cTnT and CK-MB mass were collected at arrival and 4, 8, and 12-24 later in 301 consecutive patients with recent acute chest pain (ACP). Data were also collected for cardiac events. RESULTS: Combined cardiac mortality/nonfatal myocardial infarction over a period of 15 months was lowest in patients with <0.04 microg/l cTnT and -<5.0 microg/l CK-MB mass intermediate in those with elevated cTnT but normal CK-MB mass and highest when both markers were elevated, in absence of early reperfusion. CONCLUSION: The use of a low cut-off point of cTnT, combined wit CK-MB mass determination, offers a good strategy for risk stratification of ACP patients.     

Postoperative troponin-T predicts prolonged intensive care unit length of stay following cardiac surgery

OBJECTIVE: To evaluate the use of postoperative cardiac troponin T (cTnT) for the prediction of prolonged intensive care unit length of stay following cardiac surgery. DESIGN: Prospective, single-center, observational cohort study of patients following cardiac surgical procedures. The enrollment period was from October through December 2000. Patients were enrolled on admission to the intensive care unit and followed until hospital discharge. SETTING: The cardiac surgical intensive care unit of the Massachusetts General Hospital. PATIENTS: A total of 222 consecutive patients were enrolled. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Perioperative clinical factors and serum concentrations of cTnT measured every 8 hrs after surgery were recorded. These clinical factors and the results of serum cTnT measurement were correlated with the need for prolonged intensive care unit length of stay (defined as >24 hrs). Univariable analysis identified factors predictive of prolonged intensive care unit length of stay. Stepwise logistic regression identified independent predictors of prolonged intensive care unit length of stay. Multiple linear regression was used to explore the direct relationship between cTnT concentrations at several postoperative time points and intensive care unit length of stay. At each time point assessed, cTnT concentrations from patients requiring a prolonged intensive care unit length of stay were significantly higher (all p <.001) than in those individuals with normal length of stay. In contrast, creatine kinase isoenzymes were not significantly different between patients with normal or prolonged intensive care unit length of stay. Multivariable analysis demonstrated that an immediate postoperative cTnT concentration > or =1.58 ng/mL was the strongest predictor of a prolonged intensive care unit length of stay (odds ratio, 5.6; 95% confidence interval, 2.9-10.8). Multiple linear regression analysis revealed that intensive care unit length of stay increased by 0.32 days with each incremental 1.0 ng/mL increase in cTnT measured at 18-24 hrs postprocedure. CONCLUSIONS: Elevated postoperative cTnT concentrations can prospectively identify patients requiring prolonged intensive care unit length of stay after cardiac surgery.     

Risk stratification of chest pain patients by point-of-care cardiac troponin T and myoglobin measured in the emergency department

A prospective multicenter study including 1410 chest pain patients with suspected acute coronary syndromes was carried out to examine the predictive value of biological cardiac markers for adverse events measured by a point-of-care system. Admission cardiac troponin T (cTnT) and myoglobin were measured in parallel on a point-of-care system in the emergency department and -- together with CK-MB mass -- on lab analyzers. In a one-year follow-up, cardiac and non-cardiac death, acute myocardial infarction, unstable angina pectoris and need for revascularization were registered. Median time between onset of symptoms and admission was 285 min; 172 patients (12.2%) had no event during follow-up. If the cTnT, measured either by the point-of-care system or a conventional lab analyzer, was >0.05 microg/L, then the chance of a cardiac event during the follow-up period was doubled (18% vs. 9%). Serial cTnT measurement did not add any further value to the predictive power of the admission cTnT. Myoglobin and CK-MB mass identified increasing risk with increasing concentration quartiles; cardiac event rates were 2.8- to 4.4-fold higher between the quartiles with the lowest and those with the highest analyte concentration, respectively. There was no difference in non-cardiac death rates between any concentration quartiles. In conclusion, the prediction of clinical events by cardiac troponin T and myoglobin measured with a point-of-care analyzer in the emergency department was as good as that of the same cardiac markers and CK-MB mass measured on lab analyzers.     

Combined measurements of N-terminal pro-brain natriuretic peptide and cardiac troponins in potential organ donors

Objective Brain death may induce cardiac dysfunction. In potential organ donors measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) and circulating cardiac troponins T and I (cTnT and cTnI), alone or in combination, are performed to investigate the accuracy of these biomarkers for early diagnosis of left ventricular systolic dysfunction. Design and setting Prospective study in a multidisciplinary intensive care unit of an university hospital. Patients 63 brain-dead patients scheduled for multiple organ harvesting. Measurements and results We measured NT-proBNP, cTnT, and cTnI and determined fractional area change (FAC) using transesophageal echocardiography. Forty-five patients had normal FAC, 9 a moderate decrease in FAC (30–50), and 9 a severe decrease in FAC (≤ 30%). NT-proBNP and cTnT concentrations were significantly higher in patients with a severe decrease in FAC than in those with a moderate decrease. Combining measurements of these two biomarkers, the sensitivity of the test to predict severe decrease in FAC increased significantly to reach 1.00 compared with the sensitivities of individual measurements. The ROC curve area of combined measurements of NT-proBNP and cTnT was significantly higher than single measurements: 0.87 vs. 0.82 for NT-proBNP, 0.78 for cTnT, and 0.72 for cTnI. Conclusions In potential organ donors the combined measurement of NT-proBNP and cTnT concentrations is more accurate than individual measurement of NT-proBNP, cTnT, and cTnI in the early diagnosis of severe left ventricular systolic dysfunction. These findings may lead to improve the quality of cardiac care of the potential organ donors.     

Prognostic value of serum concentration of heart-type fatty acid-binding protein relative to cardiac troponin T on admission in the early hours of acute coronary syndrome

BACKGROUND: Heart-type fatty acid-binding protein (H-FABP) is proposed as an early biomarker for acute myocardial infarction (AMI), but its prognostic value is unclear in acute coronary syndrome (ACS). We evaluated the prognostic value of the H-FABP concentration relative to cardiac troponin T (cTnT) in the early hours of ACS. METHODS: Serum concentrations of H-FABP and cTnT were measured on admission in 328 consecutive patients hospitalized for ACS within 6 h after the onset of chest pain [AMI, 241 (73.5%) patients; ST-segment elevation myocardial infarction, 154 (47.0%) patients; and emergent coronary angiography within 24 h after admission, 287 (87.5%) patients]. Cardiac events, which were defined as cardiac death or subsequent nonfatal AMI, were monitored for 6 months after admission. RESULTS: During the 6-month follow-up period, there were 25 cardiac events, including 15 cardiac deaths and 10 subsequent nonfatal AMIs. Stepwise multivariate analyses including clinical, electrocardiographic, and biochemical variables revealed that increased H-FABP (above the median of 9.8 microg/L), but not increased cTnT (above the median of 0.02 microg/L), was independently associated with cardiac events in all patients [relative risk (RR) = 8.96; P = 0.0004], the subgroup of patients with ST-segment elevation myocardial infarction (RR = 11.3; P = 0.02), and the subgroup of patients with unstable angina and non-ST-segment elevation myocardial infarction (RR = 8.31; P = 0.007). The area under the ROC curve was higher for H-FABP than for cTnT (0.711 vs 0.578; P = 0.08), suggesting that H-FABP concentrations have a greater predictive capacity for cardiac events than cTnT. CONCLUSION: Serum H-FABP is a potential independent predictor of cardiac events within 6 months of patient admission and may provide prognostic information superior to cTnT in the early hours of ACS.     

Correlation of antemortem serum creatine kinase, creatine kinase-MB, troponin I, and troponin T with cardiac pathology

BACKGROUND: Spurious increases in serum troponins, especially troponin T, have been reported in patients with and without acute myocardial syndromes. METHODS: We studied 78 autopsied patients without clinical myocardial infarction (MI) and correlated histologic cardiac findings with antemortem serum creatine kinase (CK), its MB isoenzyme (CK-MB), cardiac troponin I (cTnI), and cardiac troponin T (cTnT). RESULTS: There was no significant myocardial pathology in 15 patients. Cardiac pathologies were in five groups: scarring from previous MI or patchy ventricular fibrosis (n = 9), recent MI (n = 27), healing MI (n = 7), degenerative myocyte changes consistent with congestive heart failure (CHF; n = 12), and other cardiac pathologies (n = 8). The median concentrations in the five groups were not significantly different for either CK or CK-MB. Compared with the no-pathology group, only the MI group was significantly different for cTnI, and the MI and other pathology groups were significantly different for cTnT. For patients with MI, 22%, 19%, 48%, and 65% had increased CK, CK-MB, cTnI, and cTnT, respectively; for CHF and other cardiac pathologies combined, the percentages were 28%, 17%, 22%, and 50%. For patients with increased cTnI, 72% and 28% had MI and other myocardial pathologies, respectively; patients with increased cTnT had 64% and 36%, respectively. Patients without myocardial pathology had no increases in CK-MB, cTnI, or cTnT. CONCLUSIONS: All patients with increased serum CK-MB, cTnI, and cTnT had significant cardiac histologic changes. The second-generation cTnT assay appears to be a more sensitive indicator of MI and other myocardial pathologies than the cTnI assay used in this study.     

Myoglobin,creatine kinase MB isoforms and creatine kinase MB mass in early diagnosis of myocardial infarction in patients with acute chest pain

OBJECTIVES: Measurements of myoglobin and creatine kinase (CK)-MB isoforms have been suggested to be sensitive tests for the early diagnosis of myocardial infarction (MI). We have investigated the utility of myoglobin, creatine kinase (CK)-MB isoforms and creatine kinase MB mass (CK-MBm) in early diagnosis of MI using cardiac troponin T (cTnT) positivity as a reference. DESIGN AND METHODS: The study population comprised 440 patients who had had chest pain for less than 12 h. Patients were divided into cTnT negative (cTnT-) or cTnT positive (cTnT+) patients (concentration of cTnT >0.1 microg/L at two different time points during 72 h). RESULTS: At the time of admission to the emergency department receiver operating characteristics (ROC) curves of CK-MB isoforms and CK-MBm were not better than that of myoglobin. Six hours after admission CK-MB isoforms and CK-MBm provided statistically significantly larger areas under the curve (AUC) than myoglobin (p < 0.01). When ROC curves were related to the onset of chest pain (< 3 h, 3-6 h, and > 6 h) there were no significant differences between the cardiac markers studied. CONCLUSIONS: According to the present findings, CK-MB isoforms or myoglobin offer no advantage over CK-MBm as early markers of myocardial infarction.     

抗HLA-Ⅱ类抗体对移植肾长期存活影响的研究

目的研究肾移植术后抗HLA-Ⅱ类抗体对移植肾长期存活的影响。方法根据Terasaki基金会举办的2007年厦门会议的要求,对肾移植术后患者检测群体反应性抗体(PRA),并长期观察移植肾功能(血肌酐尿素氮)。2007年检测出156例肾移植术后抗HLA-II类抗体阳性患者,于2012年6月进行移植肾功能观察总结。PRA检测采用美国莱姆德公司提供的酶联免疫吸附法筛选HLA-Ⅰ类、Ⅱ类混合抗原板。血肌酐和尿素氮检测数据由检验科提供。由于肾移植患者术后导致肾功能下降的因素较多,故把血肌酐/尿素氮正常值115μmol/L/7.14 mmol/L提至130μmol/L/9 mmol/L。结果 2007年检测出的156例抗HLA-Ⅱ类抗体阳性患者中,102例患者移植肾功能基本正常。经过5年连续观察(2012年),102例患者中移植肾完全失去功能的患者6例,占5.77%(6/102);肾功能降低的患者16例,占15.69%(16/102);肾功能正常的患者80例,占78.43(80/102)。54例移植肾功能下降患者,占34.62%(54/156)。经过5年连续观察(2012年),目前移植肾完全失去功能的患者30例,占55.56%(30/54);肾功能降低的患者18例,占33.33%(18/54);肾功能恢复正常的患者6例,占11.11%(6/54)。抗HLA-Ⅱ类抗体阳性患者移植肾功能正常者与移植肾功能下降者,5年后两者间具有非常显著性差异(χ2=30.29,P<0.001)。结论抗HLA-Ⅱ类抗体是移植肾功能丧失的重要因素之一,但只有在移植肾功能下降时,才可增加移植肾功能丧失的几率。     

Multi-biomarker risk stratification of N-terminal pro-B-type natriuretic peptide, high-sensitivity C-reactive protein, and cardiac troponin T and I in end-stage renal disease for all-cause death

BACKGROUND: In patients with end-stage renal disease (ESRD), the ability of single and multiple biomarker monitoring to predict adverse outcomes has not been well established. This study determined the prognostic value of multiple biomarkers for all-cause death over 2 years in 399 ESRD patients. METHODS: The risk of all-cause death was determined by use of multiple biomarkers based on concentrations for a reference population (normal) and cutoffs based on tertile distributions in the ESRD group. Biomarkers studied included N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hsCRP; Dade Behring and Roche assays), and cardiac troponin T (cTnT; Roche) and I (cTnI; Dade Behring and Beckman Coulter assays). Relative risks of death were estimated and survival curves computed. RESULTS: A total of 101 deaths occurred during 594 patient-years of follow-up. Increased NT-proBNP concentrations were not predictive of death on the basis of the normal cutoffs. However, tertile analysis of NT-proBNP was significantly predictive of death and had a ROC area under the curve equivalent to or better than any of the other biomarkers. Biomarkers independently predictive of survival were hsCRP (P <0.001, either assay), cTnT (P <0.05), and cTnI (Dade, P <0.05). Two-year mortality rates were 6% (n = 45) with normal hsCRP, cTnI, and cTnT concentrations; 19% (n = 173) with increased hsCRP or cTnT and normal cTnI; 44% (n = 160) with both hsCRP and cTnT increased and normal cTnI; 61% (n = 21) with increased cTnI (Dade) or 47% (n = 74) with increased cTnI (Beckman) regardless of hsCRP or cTnT concentrations. Defined by the normal cutoffs, increased concentrations of biomarkers were present in various proportions of the 399 patients with ESRD: NT-proBNP, 99%; hsCRP, 46% (both Roche and Dade assays); cTnT, 85%; cTnI, 19% (Beckman assay) and 5% (Dade assay). CONCLUSIONS: Although mechanisms likely vary for causation, increased plasma hsCRP, cTnT, and cTnI above the cutoffs for our reference (normal) population were all independently predictive of subsequent death in ESRD patients. Tertile analysis for NT-proBNP also demonstrated prognostic value.