Serum cardiac troponin T in patients hospitalized with heart failure is associated with left ventricular hypertrophy and systolic dysfunction

Background: Cardiac troponin T (cTnT) is a highly sensitive and specific marker of acute myocardial infarction. Serum cTnT is also slightly elevated in patients with severe heart failure and is associated with left ventricular hypertrophy (LVH) in patients treated with haemodialysis. In this study serum cTnT concentrations and echocardiographic findings were investigated in heart failure patients without acute coronary syndrome. cTnT was also compared with other cardiac markers and plasma levels of brain natriuretic peptide (BNP). Methods: Twenty-six patients hospitalized with heart failure were included in the study. Echocardiographic measurements and blood sampling were carried out 12-36?h after admission. Serum cTnT (3rd generation assay), cardiac troponin I (cTnI), creatine kinase MB (CKMB) and CK were measured. Plasma BNP was analysed using the Shionoria assay. LVH was defined as left ventricular mass index (LVMI)&;gt;125?g/m&;lt;formula&;gt;²&;lt;/formula&;gt; for males and&;gt;110?g/m&;lt;formula&;gt;²&;lt;/formula&;gt; for females. Left ventricular systolic function was estimated from the mitral annulus motion (AV-mean LV). Results: Median cTnT was 0.012 (&;lt;0.010-0.032)?μg/L. Sixty-two percent of the patients (16 of 26) had elevated serum cTnT≥0.010?μg/L. cTnT was positively correlated with CKMB (ρ=0.40, p=0.04) and BNP (ρ=0.43, p=0.03), but not with cTnI and CK. A negative correlation was found between cTnT and AV-mean LV (ρ=?0.58, p=0.007), and there was a positive correlation between cTnT and LVMI (ρ=0.44, p=0.03). No other analyte was correlated to LVMI. Conclusions: Serum cTnT but not cTnI was associated with left ventricular dysfunction and LVH in patients hospitalized with heart failure. This explains why cTnT tends to be slightly elevated in patients with heart failure without symptoms of acute myocardial ischaemia.     

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.     

充血性心力衰竭患者血清肌钙蛋白T、肌钙蛋白Ⅰ检测及临床分析

目的研究充血性心力衰竭患者血清肌钙蛋白T(cTnT)和肌钙蛋白Ⅰ(cTnI)水平与心功能的关系及其对预后的判断。方法检测110例不同病因、不同心功能分级的充血性心力衰竭患者的cTnT、cTnI及左室射血分数(LVEF),并与40名健康对照组的结果进行比较。结果心功能Ⅱ级组cTnT为(78.56±25.65)pg/mL,cTnI为(0.85±0.57)ng/mL,LVEF值为57.46%±4.42%;心功能Ⅲ级分别为(249.25±76.21)pg/mL、(3.75±1.83)ng/mL、44.27%±10.13%;心功能Ⅳ级组分别为(375.62±81.29)pg/mL、(8.57±2.56)ng/mL、36.75%±5.66%,与健康对照组[分别为(3.65±0.96)pg/mL、(0.02±0.01)ng/mL、65.52%±8.01%]比较,差异有统计学意义(P<0.01),且心功能越差,cTnT、cTnI浓度越高;cTnT、cTnI与LVEF值均呈负相关,r分别为-0.487、-0.360,差异有统计学意义(P<0.01)。结论检测cTnT、cTnI对于判断充血性心力衰竭患者病情严重程度及预后具有重要的临床价值,是早期评估患者风险的重要方法。     

维持性血液透析患者血清肌钙蛋白T水平的相关影响因素分析

目的 研究维持性血液透析（maintenance hemodialysiS,MHD）患者血清心肌肌钙蛋白T（cardiac troponin T,cTnT）水平及其影响因素。方法 选取MHD治疗3个月以上的稳定患者,采用电化学发光法检测受试者血清cTnT。用Spearman相关和线性回归分析cTnT与其它指标之间的相关性。用受试者工作特征（receiver operating characteristic,ROC）曲线比较cTnT、氨基末端脑钠肽原（amino—terminal pro-brain natriuretic peptide,NT—proBNP）及高敏C反应蛋白（high sensitive C—reactive protein,hsCRP）与心血管疾病（cardiovascular disease,CVD）和左心室肥大的相关性。结果 123例MHD患者血清cTnT中位数为0．046（0．028～0．066）ng／ml。合并CVD的患者血清cTnT水平显著高于非CVD患者（0．062[0．044～0．083]ng／ml比0．031[0．020～0．046]ng／ml,P=-0．002）。糖尿病患者血清cTnT水平显著高于非糖尿病患者（0．061[0．042～0．102]ng／ml比0．044[0．025～0．064]ng／ml,P=0．003）。Spearman相关分析显示血清cTnT与年龄（ρ=0．309,P=0．002）、糖化白蛋白（ρ=0．192,P=0．040）、NT—proBNP（ρ=0．448,P〈0．001）、hsCRP（ρ=-0．335,P〈0．001）、颈动脉内膜中层厚度（ρ=0．315,P=0．004）及左心室质量指数（ρ=0．369,P〈0．001）呈正相关,与血清前白蛋白（ρ=-0．280,P=0．002）、高密度脂蛋白胆固醇（ρ=-0．201,P=0．047）呈负相关。线性回归分析显示年龄（β=0．204,P=0．043）、NT—proBNP（β=0．299,P=0．020）及左心室质量指数（β=0．345,P=0．003）与血清cTnT水平独立相关。ROC曲线分析显示cTnT水平与CVD的相关性高于NT—proBNP及hsCRP,与左心室肥大的相关性介于NT—proBNP与hsCRP之间。结论 MHD患者血清cTnT水平显著升高,cTnT水平升高与患者高龄、容量负荷、营养不良、微炎症状态、左心室肥大及伴发CVD相关。     

血浆脑利钠肽水平与原发性高血压左室肥厚的关系

目的探讨原发性高血压患者血浆脑利钠肽的水平（BNP）以及与左心室肥厚的关系。方法采用电化学发光法测定32例高血压患者无左室肥厚（NLVH组）、30例高血压患者伴左室肥厚（LVH组）、30例血压正常的健康成人（健康对照组）血浆BNP浓度。采用多普勒超声心动图检查并计算左室重量指数（LVMI）,观察BNP水平与LVMI的相关性。结果LVH组BNP水平明显高于NLVH组及健康对照组,差异有统计学意义（P〈0．01）,而NLVH组也高于健康对照组（P〈0．01）。BNP水平与LVMI呈正相关（r=0．64,P〈0．01）。结论BNP水平可以反映原发性高血压患者左室肥厚状况。     

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.     

Diagnosis and risk stratification of patients with anginal pain and non-diagnostic electrocardiograms

Patients with acute chest pain suggestive of myocardial ischaemia, and normal or non-diagnostic electrocardiograms, form a difficult subgroup for diagnosis and early risk stratification. We prospectively evaluated the role of troponin T (cTnT), troponin I (cTnI), CKMB mass and myoglobin, in the diagnosis and risk stratification of 214 patients with acute chest pain of < or = 24 h and non-diagnostic or normal ECGs admitted directly to the Cardiac Unit of the Royal Victoria Hospital Belfast from the Mobile Coronary Care Unit or the Accident/Emergency Department. This was a single-centre prospective study, and follow-up (3 months) was complete for all patients. Blood was assessed for quantitative cTnT, cTnI, CKMB mass and myoglobin, and qualitative cTnT on admission and at 12 h. Diagnosis of index event and incidence of new cardiac events (death, non-fatal myocardial infarction, revascularization, or readmission for unstable angina) over 3 months were assessed. Based on standard criteria, myocardial infarction occurred in 37/214 (17%), and unstable angina in 72/214 (34%). At 12 h from admission, cardiac troponins had higher sensitivity for the diagnosis of acute coronary syndromes (myocardial infarction and unstable angina) than conventional markers (cTnI 48%, cTnT 38%, CKMB mass 30% or myoglobin 27%). At 3 months, a new cardiac event had occurred in 42/214 (20%). Significantly higher event rates occurred when any of the biochemical markers was elevated, but the statistical significance was highest for patients with elevated cTnI (p < 0.0001). Whilst gender, history of ischaemic heart disease (IHD), stress test response, cTnT, cTnI, CKMB mass and myoglobin were univariate predictors, cTnI at 12 h and stress test response were the only two independent significant predictors for a subsequent cardiac event at 3 months. Raised cTnI at 12 h after admission had the highest sensitivity for the diagnosis of acute coronary syndromes, and was independently associated with a 2-3 times increased risk of future cardiac events within 3 months among patients with acute chest pain suggestive of myocardial ischaemia but with normal or non-diagnostic ECGs.     

Circulating natriuretic peptide concentrations in patients with end-stage renal disease: role of brain natriuretic peptide as a biomarker for ventricular remodeling.

OBJECTIVES: To determine levels of natriuretic peptides (NPs) in patients with end-stage renal disease (ESRD) and to examine the relationship of these cardiovascular peptides to left ventricular hypertrophy (LVH) and to cardiac mortality. PATIENTS AND METHODS: One hundred twelve dialysis patients without clinical evidence of congestive heart failure underwent plasma measurement of NP concentrations and echocardiographic investigation for left ventricular mass index (LVMI). RESULTS: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations correlated positively with LVMI and inversely with left ventricular ejection fraction, whereas C-type NP and Dendroaspis NP levels did not correlate with LVMI. In dialysis patients with LVH (LVMI >125 g/m2), plasma ANP and BNP concentrations were increased compared with those in dialysis patients without LVH (both P<001). In a subset of 15 dialysis patients without LVH or other concomitant diseases, plasma BNP concentrations were not significantly increased compared with those in 35 controls (mean +/- SD, 20.1+/-13.4 vs 13.5+/-9.6 pg/mL; P=.06), demonstrating that the BNP concentration was not increased by renal dysfunction alone. Furthermore, the BNP level was significantly higher in the 16 patients who died from cardiovascular causes compared with survivors (mean +/- SD, 129+/-13 vs 57+/-7 pg/mL; P<.003) and was significantly associated with greater risk of cardiovascular death in Cox regression analysis (P<.001), as was the ANP level (P=.002). CONCLUSIONS: Elevation of the plasma BNP concentration is more specifically related to LVH compared with the other NP levels in patients with ESRD independent of congestive heart failure. Thus, BNP serves as an important plasma biomarker for ventricular hypertrophy in dialysis patients with ESRD.     

Cardiac troponin and beta-type myosin heavy chain concentrations in patients with polymyositis or dermatomyositis

Cardiac troponin T (cTnT), cardiac troponin I (cTnI), myosin heavy chains (MHC), myoglobin, creatine kinase (CK), and creatine kinase isoenzyme MB (CKMB), were measured in blood samples from 39 polymyositis (PM) or dermatomyositis (DM) patients without clinical evidence for cardiac involvement to evaluate their clinical usefulness in this patient population. MHC, myoglobin, and CKMB were frequently elevated and correlated with each other and with disease severity. Undetectable cTnI in all but one patient indicated that MHC was released from skeletal muscle, thereby providing the first laboratory evidence of frequent slow-twitch muscle fibre-necrosis in patients with PM or DM. CKMB was elevated in 51%, cTnT in 41%, and cTnI in only 2.5% of patients. cTnI did not correlate with other markers or with disease severity scores. The close correlations found between cTnT and skeletal muscle damage markers and the relationship between cTnT with disease severity without clinical evidence for myocardial damage suggest a release of cTnT from skeletal muscle. The relationship of cTnT with disease severity indicates a possible role of the marker for risk stratification. However, the prognostic values of cardiac troponins and other muscle damage markers in PM/DM patients remain to be compared in prospective outcome trials.     

Acute effect of haemodialysis on serum markers of myocardial damage

Cardiac markers are more likely to be elevated in dialysis patients than in patients with renal failure not on dialysis. In this study, 31 patients (20 males, 11 females) undergoing chronic haemodialysis were enrolled. The effect of haemodialysis on cardiac troponin T (cTnT), I (cTnI), creatine kinase MB (CKMB) mass, CKMB activity and myoglobin assays was assessed by comparing pre- and post-haemodialysis determinations. After correcting for haemoconcentration, significant differences were observed (mean +/- SEM, pre- vs post-dialysis) for myoglobin (178.9 +/- 19.3 vs 225.0 +/- 28.4 ng/ml; p=0.006) for cTnT (0.111 +/- 0.028 vs 0.148 +/- 0.037 ng/ml; p=0.004), for CKMB mass (2.75 +/- 0.37 vs 2.59 +/- 0.37 ng/ml; p=0.000) and CKMB activity (14.8 +/- 0.9 vs 13.1 +/- 0.9 U/l; p=0.000) assays. Our study questions the reliability of cardiac markers in dialysis patients and suggests that the clinical threshold value and diagnostic efficiency of each assay needs to be validated. Although these differences exceeded clinical threshold values in only a few patients, serum markers of myocardial damage in dialysis patients should be interpreted with caution.     

降钙素原、BNP、心肌肌钙蛋白I及D-二聚体评估慢性心力衰竭患者预后的价值

【目的】探讨降钙素原(PCT)、B型利钠肽(BNP)、心肌肌钙蛋白I(cTnI)及D-二聚体(D-D)评估慢性心力衰竭(CHF)患者预后的价值。【方法】本院就诊的70例CHF患者作为CHF组,根据美国纽约心脏病协会颁布的心功能分级标准(NYHA)分级法分为心功能Ⅱ级组、心功能Ⅲ级组、心功能Ⅳ级组,分别为33例、26例、11例。同时选取同一时期本院70例体检正常者分为对照组。采集所有研究对象入院时及1个月后的血液标本,对所有研究对象血清PCT、BNP、cTnI及D-D进行检测,并进行统计分析。【结果】CHF组血清PCT、BNP、cTnI及D-D水平均较对照组高,其差异具有显著性(P均<0.05)。CHF组中心功能Ⅱ级组、心功能Ⅲ级组、心功能Ⅳ级组血清PCT、BNP、cTnI及D-D水平随着心衰程度加重而逐渐升高,三组间两两比较差异均具有显著性(P均<0.05)。CHF患者经治疗1月后,血清PCT、BNP、cTnI、D-D水平明显较治疗前降低,其差异具有显著性(P<0.01);CHF患者经治疗1月后左室射血分数(LVEF)较治疗前升高,且差异具有显著性(P<0.01);CHF患者经治疗1月后NYHA心功能级别较治疗前明显降低,且差异具有显著性(P<0.01)。血清PCT、BNP、cTnI、D-D水平与NYHA心功能级别均呈正相关(P均<0.05),与LVEF均呈负相关(P均<0.05)。【结论】血清中PCT、BNP、CTnI、D-D水平均可对CHF患者病情变化进行反映,对于CHF患者疗效监测具有重要预测价值。     

Clinical and experimental results on cardiac troponin expression in Duchenne muscular dystrophy

BACKGROUND: Because of controversial earlier studies, the purpose of this study was to provide novel experimental and additional clinical data regarding the possible reexpression of cardiac troponin T (cTnT) in regenerating skeletal muscle in Duchenne muscular dystrophy (DMD). METHODS: Plasma from 14 patients (mean age, 7.5 years; range, 5.7-19.4 years) with DMD was investigated for creatine kinase (CK), the CK MB isoenzyme (CKMB), cTnT and cardiac troponin I (cTnI), and myoglobin. cTnT concentrations were measured by an ELISA (second-generation assay; Roche) using the ES 300 Analyzer. cTnI, myoglobin, and CKMB were measured by an ELISA using the ACCESS System (Beckman Diagnostics). Troponin isoform expression was studied by Western blot analysis in remnants of skeletal muscle biopsies of three patients with DMD and in an animal model of DMD (mdx mice; n = 6). RESULTS: There was no relation of cTnT and cTnI to clinical evidence for cardiac failure. cTnI concentrations remained below the upper reference limit in all patients. cTnT was increased (median, 0.11 microg/L; range, 0.06-0.16 microg/L) in 50% of patients. The only significant correlation was found for CK (median, 3938 U/L; range, 2763-5030 U/L) with age (median, 7.5 years; range, 6.8-10.9 years; r = -0.762; P = 0.042). Western blot analysis of human or mouse homogenized muscle specimens showed no evidence for cardiac TnT and cTnI expression, despite strong signals for skeletal muscle troponin isoforms. CONCLUSIONS: We found no evidence for cTnT reexpression in human early-stage DMD and in mdx mouse skeletal muscle biopsies. Discrepancies of cTnT and cTnI in plasma samples of DMD patients were found, but neither cTnT nor cTnI plasma concentrations were related with other clinical evidence for cardiac involvement.     

慢性心力衰竭患者血清BNP、cTnI、Hcy水平与心功能、室性心律失常的相关性研究

目的 探讨慢性心力衰竭患者血清B型利钠肽(BNP)、心肌肌钙蛋白I(cTnI)、同型半胱氨酸(Hcy)水平与心功能、室性心律失常的相关性.方法 选择2018年6月至2019年6月东莞市人民医院80例慢性心力衰竭患者为研究对象,依据美国纽约心脏病学会(NYHA)心功能分级分组,住院期间有无发生室性心律失常分组,同期选择7...     

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.     

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.     

Heart remodeling in patients with predialysis phase of chronic renal failure

AIM: To investigate remodeling of the heart in patients with predialysis phase of chronic renal failure (CRF). MATERIAL AND METHODS: Patients with predialysis phase of CRF (n = 61; serum creatinine 412.4 +/- 242.69 mumol/l), essential hypertension (EH) (n = 35) and healthy volunteers (n = 20) were assessed with echocardiography. The patients were not significantly different by the level of systolic and diastolic blood pressure, age and gender. RESULTS: Left ventricular mass index (LVMI) was increased in 53(86.9%) patients with CRF. LVMI was not different in patients with CRF and EH (189.9 +/- 71.35 vs. 165.0 +/- 41.83 g/m2; p = 0.3). Relative wall thickness was similar in patients with serum creatinine < 200 mumol/l and patients with more elevated serum creatinine (57.2 +/- 10.33 vs 58.31 +/- 13.33; p = 0.9). The ejection fraction lower than 50% was detected in 14(22.9%) patients with CRF. Multivariate regression analysis showed that LVMI was independently related to systolic blood pressure (p = 0.004) and level of hemoglobin (p = 0.004). Diastolic dysfunction (early and atrial peak filling velocities ratio < 1.0) was detected in 13(50%) from 26 investigated patients with CRF. The independent influence of hemoglobin on isovolumic relaxation time (p = 0.04) and early and atrial peak filling velocities ratio (p = 0.02) are shown. CONCLUSION: In patients with predialysis phase of CRF left ventricular hypertrophy (LVH) is extremely common including patients with mildly elevated serum creatinine. The treatment of patients with renal pathology and normal function must include measures not only to correct renal process but also to prevent development of LVH.     

Analytical and diagnostic performance of troponin assays in patients suspicious for acute coronary syndromes

BACKGROUND: The controversy whether there is a clinically significant difference between troponin T (cTnT) and troponin I (cTnI) in regard to predictive value and cardiac specificity is still ongoing. METHODS: We evaluated enzyme-linked immunosorbent assay systems for cTnI and cTnT in patients with acute coronary syndromes and multiple control groups to define threshold values for risk stratification and compare their predictive value. RESULTS: In 312 patients with noncardiac chest pain, cTnI levels were below the detection limit of 0.2 microg/L and cTnT levels were 0.011 [0.010-0. 013] microg/L. In patients with end-stage renal failure (n = 26) and acute (n = 38) or chronic (n = 16) skeletal muscle damage, median concentrations were 0.20 [0.20-0.35], below the detection limit, and 0.20 [0.20-0.25] for cTnI, and 0.04 [0.01-0.10], 0.011 [0.005-0.025], and 0.032 [0.009-0.054] microg/L for cTnT. In patients with acute coronary syndromes (n = 1130), maximized prognostic value for 30-day outcome (death, infarction) was observed at a threshold level of 1.0 microg/L for cTnI (29.0% positive) and at 0.06 microg/L for cTnT (35. 0% positive). Significant differences in the area-under-the-curve values were observed between cTnI and cTnT (0.685 vs. 0.802; p = 0. 005). For both markers, the area-under-the-curve values did not increase with the second (within 24 h after enrollment) or third (48 h) blood draw. CTnI showed a less strong association with 30-day outcome than cTnT. When cTnI was put in a logistic multiple-regression model first, cTnT did add significant information. CONCLUSION: By using the defined threshold values and the employed test systems, single testing for cTnI and cTnT within 12 h after symptom onset was appropriate for risk stratification. Despite the lower cardiac specificity for cTnT, it appears to have a stronger association with the patients' outcome, whereas, as previously shown, the ability to identify patients who benefit from treatment with a GP IIb/IIIa receptor antagonist is similar.     

Prognostic value of combination of cardiac troponin T and B-type natriuretic peptide after initiation of treatment in patients with chronic heart failure

BACKGROUND: Recent studies have suggested that cardiac troponin T (cTnT) and troponin I may detect ongoing myocardial damage involved in the progression of chronic heart failure (CHF). This study was prospectively designed to examine whether the combination of cTnT, a marker for ongoing myocardial damage, and B-type natriuretic peptide (BNP), a marker for left ventricular overload, would effectively stratify patients with CHF after initiation of treatment. METHODS: We measured serum cTnT, plasma BNP, and left ventricular ejection fraction (LVEF) on admission for worsening CHF [New York Heart Association (NYHA) functional class III to IV] and 2 months after initiation of treatment to stabilize CHF (n = 100; mean age, 68 years). RESULTS: Mean (SD) concentrations of cTnT [0.023 (0.066) vs 0.063 (0.20) micro g/L] and BNP [249 (276) vs 753 (598) ng/L], percentage increased cTnT (>0.01 micro g/L; 35% vs 60%), NYHA functional class [2.5 (0.6) vs 3.5 (5)], and LVEF [43 (13)% vs 36 (12)%] were significantly (P <0.01) improved 2 months after treatment compared with admission. During a mean follow-up of 391 days, there were 44 cardiac events, including 12 cardiac deaths and 32 readmissions for worsening CHF. On a stepwise Cox regression analysis, increased cTnT and BNP were independent predictors of cardiac events (P <0.001). cTnT >0.01 micro g/L and/or BNP >160 ng/L 2 months after initiation of treatment were associated with increased cardiac mortality and morbidity rates. CONCLUSION: The combination of cTnT and BNP measurements after initiation of treatment may be highly effective for risk stratification in patients with CHF.     

心肌肌钙蛋白Ⅰ和肌钙蛋白T对急性缺血性心脏病预后相关性分析

目的探讨心肌肌钙蛋白I(cTnI)和肌钙蛋白T(cTnT)对急性缺血性心脏病转归的影响。方法对就诊的急性缺血性心脏病患者定性测定入院时及距胸痛发作间隔10h的cTnI和定量测定相同时点的cTnT。同时随访患者发病后1、3、6、12个月的疾病转归,以心绞痛、心肌梗死、心力衰竭、心源性猝死为终点评价指标。结果cTnI或cTnT异常患者与正常者相比较,不稳定型心绞痛、心肌梗死、心力衰竭、心源性猝死的发生率具有显著性差异(P<0.01)。cTnI或cTnT异常与终点事件(不稳定型心绞痛、心肌梗死、心力衰竭、心源性心源性猝死)发生率呈正相关。结论cTnI或cTnT对急性心肌梗死,尤其是微小心肌坏死诊断具有高度的敏感性和特异性,并与急性缺血性心脏病的预后密切相关。     

Plasma brain natriuretic peptide and cardiac troponin I concentrations after adult cardiac surgery: association with postoperative cardiac dysfunction and 1-year mortality

OBJECTIVE: The purpose of the present study was to evaluate the prognostic implications of perioperative B-type natriuretic peptide (BNP) and cardiac troponin I concentrations in patients undergoing cardiopulmonary bypass for cardiac surgery. DESIGN: Prospective observational study. SETTING: Biochemistry laboratory and surgical care unit in a university hospital. PATIENTS: A total of 92 consecutive patients undergoing elective coronary artery (43 patients) or valve surgery (49 patients). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BNP and cardiac troponin I concentrations were measured before surgery (day 0), and at day 1 after surgery. Postoperative cardiac dysfunction was defined as low cardiac output or hemodynamic instability requiring inotropic support for >24 hrs or congestive heart failure until day 5. One-year survival was also evaluated. Univariate and multivariate analyses were performed. An important BNP secretion was systematically observed after cardiac surgery. Independent predictors of cardiac dysfunction were preoperative New York Health Association class and BNP and cardiac troponin I concentrations measured at day 1. Patients with an elevation of both markers have a 12-fold increased risk of postoperative heart failure. The use of both markers in combination predicted better postoperative heart failure than each one separately. Age, low preoperative left ventricular ejection fraction, and elevated BNP at day 1 (>352 pg/mL) were associated with an increased mortality rate at 1 yr. In multivariate analysis, only left ventricular ejection fraction was significantly associated with 1-yr survival. CONCLUSIONS: Postoperative plasma BNP and cardiac troponin I levels are independent predictors of postoperative cardiac dysfunction after cardiac surgery. Simultaneous measurement of BNP and cardiac troponin I improve the risk assessment of postoperative cardiac dysfunction. However, the association between BNP levels and 1-yr outcome was no longer significant after adjustment on left ventricular ejection fraction.