Rapid risk stratification in suspected acute coronary syndrome using serial multiple cardiac biomarkers: A pilot study

Objective: To determine the feasibility of using a biomarker panel of myoglobin, creatinine kinase MB (CK‐MB) and cardiac troponin I (cTnI) to identify patients with suspected acute coronary syndrome (ACS) who are suitable for discharge within 2 h. Methods: We took blood at presentation and at 2 h from patients with suspected ACS and non‐diagnostic electrocardiogram who were admitted to the ED short stay ward for serial electrocardiogram and troponin testing. We used a point‐of‐care device that gives rapid estimation of myoglobin, CK‐MB and cTnI (Triage cardiac panel). These results were compared with the results of our standard hospital cardiac troponin T assay. Patients were followed up by telephone at 30 days. Results: The study group comprised 100 patients (61 men) with mean age of 58 years. Six had a troponin‐positive ACS during their ED stay. One additional patient died of a myocardial infarction within the follow‐up period. The Triage panel at 2 h after presentation predicted 12‐h cardiac troponin T elevation (sensitivity 100%, negative predictive value 99%) and 30‐day events (sensitivity 86%, negative predictive value 97%). The majority of patients were ultimately suitable for discharge. Conclusion: Serial myoglobin, CK‐MB and cTnI have the potential to identify patients who are suitable for early discharge and outpatient work‐up. A large multicentre study is required.     

Laboratory diagnosis of patients with acute chest pain.

The enzyme activities of creatine kinase (CK), its isoenzyme MB (CK-MB) and of lactate dehydrogenase isoenzyme 1 (LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction (AMI) from non-AMI patients. These methods are easy to perform as automated analyses, but they are not specific for cardiac muscle damage. During the early 90's the situation changed. First creatine kinase MB mass (CK-MB mass) replaced the measurement of CK-MB activity. Subsequently cardiac-specific proteins troponin T (cTnT) and troponin I (cTnI) appeared on the scene, displacing LD-1 analysis. However, troponin concentrations in blood increase only from four to six hours after onset of chest pain. Therefore a rapid marker such as myoglobin, fatty acid binding protein or glycogen phosphorylase BB could be used in early diagnosis of AMI. On the other hand, CK-MB isoforms alone may also be useful in rapid diagnosis of cardiac muscle damage. Myoglobin, CK-MB mass, cTnT and cTnI are nowadays widely used in diagnosing patients with acute chest pain. Myoglobin is not cardiac-specific and therefore requires supplementation with some other analyses such as troponins to support the myoglobin value. Troponins are very highly cardiac-specific. Only the sera of some patients with severe renal failure, which requires hemodialysis, have elevated cTnT and/or cTnI without there being any evidence of cardiac damage. On the other hand, the latest studies have shown that elevated troponin levels in sera of hemodialysis patients point to an increased risk of future cardiac events in a similar manner to the elevated troponin values in sera of patients with unstable angina pectoris. In addition, the bedside tests for cTnT and cTnI alone or together with myoglobin and CK-MB mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain. These rapid tests are easy to perform and they do not require expensive instrumentation. For routine clinical laboratory practice we suggest that in diagnosis of patients with chest pain, myoglobin and CK-MB mass measurements should be performed whenever they are requested (24 h/day) and cTnT or cTnI on admission to the hospital and then 4-6 and 12 hours later.     

联合检测CTnI、MB和心肌酶学在评价心肌损伤中的应用

目的 探讨人血中心肌肌钙蛋白I(CTnI)、肌红蛋白(MB)和心肌酶学在心肌损伤中的临床意义.方法 对80例急性冠状动脉综合征(ACS)患者血清中CTnI、MB和肌酸激酶同工酶(CK-MB)进行联合检测,CTnI、MB采用化学发光法,CK-MB采用日本OLYMPUS-AU400全自动生化分析仪.结果 在检测的80例ACS患者血清中CTnI增高66例,MB增高46例,CK-MB增高42例,而健康体检组三项检测均正常.结论 联合检测CTnI、MB、CK-MB水平,可提高ACS诊断率.     

Serum and plasma as alternative sample types in analysis of cardiac markers in the clinical routine

There is an increasing demand for the results of cardiac markers (troponin I or T, creatine kinase MB mass and myoglobin) to be made available promptly after sample-taking. In order to shorten the turnaround time, the possibility of using EDTA- or heparin-plasma instead of serum was investigated. The study population comprised 391 patients with acute chest pain. Four different instruments and systems routinely used in Finland giving quantitative results were studied for the assays of creatine kinase isoenzyme MB mass, myoglobin, and troponin I or troponin T. In addition to serum samples, heparin-plasma seems to be useful for all three assays using the Access and Immulite systems, while EDTA-plasma seems to be useful for all three assays with the Access and Elecsys systems. For the AxSYM assays, serum samples seem to be the best alternative. In conclusion, it is possible to use a single EDTA- or heparin-plasma sample for Access, Elecsys and Immulite analysers, and thereby to shorten the turnaround time. In this way the quantitative analyses from plasma can be performed 30 min after taking the sample.     

Serum and plasma as alternative sample types in analysis of cardiac markers in the clinical routine

There is an increasing demand for the results of cardiac markers (troponin I or T, creatine kinase MB mass and myoglobin) to be made available promptly after sample-taking. In order to shorten the turnaround time, the possibility of using EDTA- or heparin-plasma instead of serum was investigated. The study population comprised 391 patients with acute chest pain. Four different instruments and systems routinely used in Finland giving quantitative results were studied for the assays of creatine kinase isoenzyme MB mass, myoglobin, and troponin I or troponin T. In addition to serum samples, heparin-plasma seems to be useful for all three assays using the Access and Immulite systems, while EDTA-plasma seems to be useful for all three assays with the Access and Elecsys systems. For the AxSYM assays, serum samples seem to be the best alternative. In conclusion, it is possible to use a single EDTA- or heparin-plasma sample for Access, Elecsys and Immulite analysers, and thereby to shorten the turnaround time. In this way the quantitative analyses from plasma can be performed 30 min after taking the sample.     

Increased troponin I is associated with fatal outcome in acquired thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) has >90% mortality without therapeutic plasma exchange (TPE). Despite TPE, approximately 10% of patients still die, presumably from cardiac ischemia. We sought clinical or laboratory parameters associated with death by reviewing the records of all patients hospitalized with acquired TTP in our institution for 10 years, and collect demographics and results for hemoglobin, platelet count, creatinine, lactate dehydrogenase, transaminases, total bilirubin, creatinine kinase (CK), CK‐MB, and troponin I. Sixty‐eight patients were admitted 88 times, and 11 died. Survivors and non‐survivors were similar in terms of sex, ethnicity, thrombocytopenia, and degree of anemia at presentation, while the latter were older, had worse renal function and higher CK, CK‐MB, and troponin I (univariate analysis). However, only troponin I remained significant on multivariate analyses. We propose that patients with TTP should be monitored with troponin I to detect significant myocardial ischemia that could predict death despite TPE.     

心肌标志物在心脏手术后的应用价值

目的　观察两组心脏外科手术患者术后 4 8h内各心肌标志物测定值的变化 ,评价其对判断心肌损伤程度的应用价值。方法　两组心脏外科手术患者术后 4 8h内不同时间分别采集静脉血 ,测定心肌肌钙蛋白T(cTnT)、肌红蛋白 (Myo)、肌酸激酶MB同工酶 (CK MB)活性、CK MB蛋白量等心肌标志物浓度 ,评价他们在心脏手术后的应用价值。结果　微创冠脉搭桥手术组术后CK MB出现轻度增高 ,cTnT基本不出现增高 ;在心肌损伤较大的换瓣手术组术后CK MB、cTnT出现明显增高。两组术后Myo都出现明显增高。对照组 (胸外科手术 )中cTnT均未升高 ,而其他各标志物都有不同程度升高。结论　cTnT在判断心脏外科手术后心肌损伤程度上最具应用价值     

Validation of NACB and IFCC guidelines for the use of cardiac markers for early diagnosis and risk assessment in patients with acute coronary syndromes

BACKGROUND: International guidelines have been established for the use of cardiac markers in the early diagnosis and risk assessment of patients with acute coronary syndromes. METHODS: A single center, prospective observational study was conducted in a tertiary care university hospital on 200 consecutive patients with suspected acute myocardial infarction (AMI). Blood was drawn on admission and after 2, 4, 8, 12 and 24 h for the measurement of CK-MB/CK activity, myoglobin, CK-MB mass and troponin I. A 6-week follow-up was undertaken for the combined end point of acute coronary syndrome and death. RESULTS: Myoglobin showed an early diagnostic sensitivity of 0.65 on admission, 0.90 after 2 h and 0.92 after 4 h compared with 0.46, 0.74 and 0.88 for CK-MB/CK activity. The combination of myoglobin and cTnI increased the diagnostic value compared with myoglobin alone on admission, 2 and 4 h later. In multivariate analysis, cTnI and CK-MB/CK mass, but not myoglobin and CK-MB/CK activity, were shown to be independent predictors on the 6-week follow-up. CONCLUSIONS: Repetitive myoglobin measurements within 4 h of admission, combined with at least one early troponin test, was shown to be the strategy of choice in early AMI diagnosis and prognosis assessment.     

手足口病患儿联合检测肌酸激酶同工酶MB、心肌肌钙蛋白Ⅰ在合并病毒性心肌炎诊断中的价值

目的探讨手足口病患儿联合检测血清中肌酸激酶同工酶MB（CK—MB）、心肌肌钙蛋白Ⅰ（cTnI）水平对诊断合并病毒性心肌炎的价值。方法将188倒HFMD患儿分为确诊合并精毒性心肌炎组、疑似舍并病毒性心肌炎组、无合并病毒性心肌灸组。所有惠儿清晨空腹采集静脉血,检测血清中的肌酸激酶同工酶MB（CK—MB）、心肌肌钙蛋白Ⅰ（cTnI）水平,对结果进行统计分析。结果确诊合并病毒性心肌炎组与疑似合并病毒性心肌炎组血清中CK—MB、cTnI均高于无合并病毒性心肌炎组,差异有统计学意义（P〈0．05）;确诊合并病毒性心肌炎组血清中CK—MB、cTnI与疑似合并病毒性心肌炎组比较差异无统计学意义（P〉0．05）。确诊组与疑似组两项检测中的总异常率均分别高于两纽中CK—MB、cTnI单独检测异常率（P〈0．05,P〈0．05）。结论CK—MB、cTnI在HFMD中诊断合并病毒性心肌炎有重要意义;HFMD患儿同时检测血清中CK—MB、cTrI水平,可以提高合并病毒性心肌炎的捡出率。     

Asystole and increased serum myoglobin levels associated with ‘packing blackout’ in a competitive breath‐hold diver

Many competitive breath‐hold divers use ‘glossopharyngeal insufflation’, also called ‘lung packing’, to overfill their lungs above normal total lung capacity. This increases intrathoracic pressure, decreases venous return, compromises cardiac pumping, and reduces arterial blood pressure, possibly resulting in a syncope breath‐hold divers call ‘packing blackout’. We report a case with a breath‐hold diver who inadvertently experienced a packing blackout. During the incident, an electrocardiogram (ECG) and blood pressure were recorded, and blood samples for determinations of biomarkers of cardiac muscle perturbation (creatine kinase‐MB isoenzyme (CK‐MB), cardiac troponin‐T (TnT), and myoglobin) were collected. The ECG revealed short periods of asystole during the period of ‘packing blackout’, simultaneous with pronounced reductions in systolic, diastolic, and pulse pressures. Serum myoglobin concentration was elevated 40 and 150 min after the incident, whereas there were no changes in CK‐MB or TnT. The ultimate cause of syncope in this diver probably was a decrease in cerebral perfusion following glossopharyngeal insufflation. The asystolic periods recorded in this diver could possibly indicate that susceptible individuals may be put at risk of a serious cardiac incident if the lungs are excessively overinflated by glossopharyngeal insufflation. This concern is further substantiated by the observed increase in serum myoglobin concentration after the event.     

心肌肌钙蛋白I、肌钙蛋白T、肌酸激酶同工酶MB早期诊断 急性心肌梗死敏感性及特异性比较分析

目的 探讨心肌肌钙蛋白Ⅰ（cTnI)、 肌钙蛋白T（cTnT)、 肌酸激酶同工酶MB（CK－MB）早期诊断急性心肌梗死的临床应用价值。方法 对60例急性心肌梗死（AMI）和40例不稳定型心绞痛（UA）患者的同一血样标本检测cTnI、cTnT、CK－MB3项指标,分别进行两组间比较,并对 AMI组和UA组各指标作对比分析。结果 cTnI、cTnT早期诊断急性心肌梗死灵敏度高于CK－MB,阳性率分别为63.3%、46.7%、18.3％,P＜0.01;cTnI和cTnT无显著差别,P＞0.05;cTnI、cTnT、CK－MB特异性相当。结论 心肌肌钙蛋白I和肌钙蛋白T对于AMI的早期诊断具有较高灵敏度和较强特异性,是心肌损伤特异笥标志物,cTnI检测方便、快捷、准确,具有较好的临床价值。     

Ability of myoglobin to predict mortality in patients admitted for exclusion of myocardial infarction

Background

Myoglobin can be used as an early marker to diagnose myocardial infarction (MI); and although nonspecific for myocardial necrosis, it seems to be a strong mortality predictor. Because myoglobin elevations are often present in patients with renal insufficiency, it is possible that the predictive value of myoglobin is secondary to identifying patients with renal insufficiency.

Methods

Consecutive patients admitted for MI exclusion without ST elevation on the initial electrocardiogram underwent serial assessment of cardiac markers (creatine kinase [CK], CK–myocardial band [MB], and troponin I [TnI]). Myoglobin was assessed at the time of admission and/or 3 hours later. Renal insufficiency was defined as a creatinine clearance <60 mL/min. Multivariate analysis was performed to identify predictors of 30-day and 1-year all-cause mortality.

Results

A total of 3461 patients were included in the analysis. Overall 30-day and 1-year mortality was 2.4% and 9.7%. Myoglobin was elevated in 675 (20%), CK-MB in 421 (12%), and TnI in 517 (15%). Among the 993 patients with renal insufficiency, myoglobin was elevated in 43%, CK-MB in 17%, and TnI in 21%. Independent predictors of 30-day and 1-year mortality were similar and included age ≥65 years, prior MI, and an ischemic electrocardiogram, whereas myoglobin was the strongest multivariate predictor (odds ratio [OR] 2.8, 95% confidence interval [CI] 2.1-3.7), including those with renal insufficiency (OR 2.3, 95% CI 1.6-3.4). Troponin I had borderline predictive value (P = .08, OR 1.4, 95% CI 0.96-2.0), whereas CK-MB was not predictive in either group.

Conclusions

Despite the absence of cardiac specificity, an elevated myoglobin strongly predicts mortality, even in patients with renal insufficiency.     

不同抗凝剂对5种特定蛋白检测结果的影响

目的观察常见的4种血样采集管对C3、C4、IgA、IgG、IgM这5项生化项目检测结果的影响,探讨能否用抗凝血浆替代血清用于生化检测。方法对43名体检人员的静脉血管,连续用乙二胺四乙酸二钾(EDTA-K_2)抗凝管、肝素锂抗凝管、普通血清管、枸橼酸钠抗凝管各抽取一管血液,经混匀、离心分离后提取血清或血浆在仪器上同时用C3、C4、IgA、IgG、IgM试剂盒进行测定。结果在相同条件下,5个项目中肝素锂抗凝管与普通血清管比较差异无统计学意义(P0.05),枸橼酸钠抗凝管与用普通血清管的结果比较差异有统计学意义(P0.05),EDTA-K_2抗凝管与用普通血清管的结果比较,IgA、IgM、IgG差异无统计学意义(P0.05),C3、C4差异有统计学意义(P0.05)。结论 IgA、IgM、IgG生化检验项目可用肝素锂抗凝血浆和EDTAK2血浆代替血清,C3和C4生化检验项目可用肝素锂抗凝血浆代替血清,但C4应建立血浆参考区间。     

心肌标志物检测在早期诊断急性心肌梗死中的价值

目的探讨胶体金免疫层析法检测血清肌钙蛋白Ⅰ、肌酸激酶同工酶（CK-MB）、肌红蛋白在急性心肌梗死（AMI）患者早期不同时间段的诊断价值。方法收集该院2011年1月至2012年12月收治的89例AMI病例,根据发病时间分为两组,2～〈6h组42例,6～12h组为47例,非心肌梗死对照组70例。采用血清肌钙蛋白Ⅰ、CK-MB、肌红蛋白三合一诊断试剂对选取的病例进行测定。结果AMI患者肌钙蛋白Ⅰ、CK-MB、肌红蛋白的阳性率均高于对照组（P〈0．05）,在2～〈6h时间段内三者的敏感度分别为35．7％、64．3％、52．4％,均低于6～12h时间段的48．9％、85．1％、76．6％,结果差异有统计学意义（P〈0．05）。CK-MB用于诊断的敏感度在两个时间段内分别为：64．3％、85．1％,较肌钙蛋白I（35．7％、48．9％）、肌红蛋白（52．4％、76．6％）高,差异有统计学意义（P〈0．05）,而肌红蛋白敏感度较肌钙蛋白Ⅰ高（P〈0．05）。将三者联合测定时,阳性率高于单独测定时的阳性率,2～6h组阳性率为69．0％,6～12h组阳性率为89．4％。结论在AMI早期,肌钙蛋白Ⅰ、CK-MB、肌红蛋白单独测定阳性率较低,不能满足临床需要,而采用胶体金法心肌三合一诊断试剂盒,对肌钙蛋白Ⅰ、CKMB、肌红蛋白进行联合测定能提高AM1的早期诊断阳性率,以便为临床提供可靠的实验信息,及时采取有效的治疗措施,从而降低患者的病死率。     

3种血清心肌标志物联合检测在急性冠状动脉综合征诊断中的应用

目的：探讨肌红蛋白（Mb）、心肌肌钙蛋白I（cTnI）、肌酸激酶同工酶 MB型（CK-MB）联合检测在急性冠状动脉综合征（ACS）诊断中的价值。方法选取85例ACS患者[其中不稳定型心绞痛（UA）25例、心肌梗死60例]作为ACS组,除ACS外的冠心病（CHD）患者68例作为CHD组,60例健康体检者作为健康组进行血清 Mb、cTnI、肌酸激酶（CK）、CK-MB检测,并进行统计学分析和评价。结果 ACS组患者血清Mb、cTnI、CK-MB水平均高于CHD组及健康组,差异有统计学意义（P＜0．05）。结论血清 Mb是ACS诊断中敏感且较特异的生化指标,Mb、cTnI、CK-MB联合检测有助于ACS早期的快速诊断和鉴别诊断,具有重要的临床意义。     

Early Diagnostic Efficiency of Cardiac Troponin I and Troponin T for Acute Myocardial Infarction

Objective : To compare the early diagnostic efficiency of the cardiac troponin I (cTn-I) level with that of the cardiac troponin T (cTn-T) level, as well as the creatine kinase (CK), CK-MB, and myoglobin levels, for acute myocardial infarction (AMI) in patients without an initially diagnostic ECG presenting to the ED within 24 hours of the onset of their symptoms. Methods : A prospective, observational, cohort study was performed involving chest pain patients admitted to a large urban community hospital. Participants were consecutive consenting ED chest pain patients ≥30 years of age. Exclusions included duration of symptoms >24 hours, inability to complete data collection, receipt of CPR, and ST-segment elevation on the initial ECG. Measurements included levels of cTn-I, cTn-T, CK, CK-MB, and myoglobin at the time of presentation and 1, 2, 6, and 12–24 hours after presentation as well as presenting ECG and clinical follow-up. Confirmation of the diagnosis of AMI was based on World Health Organization criteria. Results : Of the 177 patients included in the study, 27 (15%) were diagnosed as having AMIs. The sensitivities of all 5 biochemical markers for AMI were poor at the time of ED presentation (3.7–33.3%) but rose significantly over the study period. The sensitivity of cTn-T was significantly better than that of cTn-I over the initial 2 hours, but both markers' sensitivities were low (<60%) during this time frame. The cTn-I was significantly more specific for AMI than was the cTn-T, but not significantly better than CK-MB or myoglobin. Likelihood ratio analysis showed that the biochemical markers with the highest positive likelihood ratios for AMI during the first 2 hours following ED presentation were myoglobin and CK-MB. From 6 through 24 hours, the positive likelihood ratios for cTn-I, CK-MB, and myoglobin were superior to those of CK and cTn-T. Conclusions : cTn-I, CK-MB, and myoglobin are significantly more specific for AMI than are CK and cTn-T. Myoglobin is the biochemical marker having the highest combination of sensitivity, specificity, and negative predictive value for AMI within 2 hours of ED presentation. Neither cTn-I nor cTn-T offers significant advantages over myoglobin and CK-MB in the early (≤2 hours) initial screening for AMI. The cardiac troponins are of benefit in identifying AMI ≤6 hours after presentation.     

3项指标早期联合筛查小儿病毒性心肌炎效果分析

目的探讨心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)及超敏C反应蛋白(hs-CRP)联合诊断筛查小儿病毒性心肌炎(VMC)的效果。方法选取75例VMC患儿作为心肌炎组,另选取同期健康体检儿童75例作为健康对照组;比较两组cTnI、CK-MB、hs-CRP水平,分析cTnI、CK-MB、hs-CRP、cTnI+CK-MB+hs-CRP筛查VMC的灵敏度、特异度及准确度。结果心肌炎组CTnI、CK-MB、hs-CRP水平均明显高于健康对照组,差异有统计学意义(P0.05);cTnI筛查VMC的灵敏度、特异度、准确度分别为68.0%、98.7%、83.3%,CK-MB分别为56.0%、88.0%、72.0%,hs-CRP分别为73.3%、76.0%、74.7%,cTnI+CK-MB+hs-CRP分别为89.3%、94.7%、92.0%。结论 cTnI、CK-MB、hs-CRP单独筛查VMC缺乏较为全面的灵敏度和特异度,而采取联合筛查可获取较高的灵敏度、特异度和准确度。     

Heparin plasma sampling as an alternative to EDTA for BNP determination on the Access-Beckman Coulter--effect of storage at -20 degrees C

To determine BNP, EDTA plasma is the only suitable specimen recommended by the manufacturer. Since many laboratories, especially in Europe, use heparin plasma rather than EDTA plasma for many or most of their clinical assays and in particular for determination of cardiac markers (cTnI, myoglobin), it appeared critical to evaluate the use of heparin plasma samples, in comparison to EDTA plasma, for BNP determination on a automated immunochemiluminescent analyzer. The aim of this study was first, to evaluate the use of heparin plasma samples for Biosite BNP testing on the Beckman Coulter Access Immunoassay System (n=88) and second, to evaluate the effect of storage at -20 degrees C, without protease inhibitors, on the Biosite BNP assay. We obtained acceptable imprecision results with CVs ranging from 1.7 to 11.7% regardless of the anticoagulant used. The linearity of EDTA samples was good and comparable to the results observed with heparin plasma. The concentration of BNP was categorized according to the classification of the New York Heart Association (NYHA). With EDTA fresh samples as reference anticoagulant, 90% vs. 89% of subjects were classified as "concordant" with heparin fresh vs heparin frozen plasma samples, respectively. After storage at -20 degrees C, only 86% of the values of EDTA frozen were concordant with values of EDTA fresh. No subject varied by two NYHA classes. Heparin plasma is an attractive alternative to the established EDTA samples which can be used for BNP determination. This flexibility allows the simultaneous determination of CK, CK-MB, cTnI and BNP on a single heparin specimen, which facilitates blood collection for clinicians and nursing staff in an emergency unit. In addition, our results suggest that BNP could be stored at -20 degrees C for at least one month in order to perform retrospective studies.     

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.     

Elevation of creatine kinase in acute severe asthma is not of cardiac origin

OBJECTIVE: To study prospectively if, when plasma creatine kinase (CK) and plasma myoglobin are elevated, the origin of these abnormalities is cardiac or not, by measuring cardio-specific troponin T (cTT). METHOD: Fifteen patients with acute severe bronchial asthma (ASBA) were prospectively studied in the intensive care unit (ICU) with continuous electrocardiograph (ECG). Plasma CK, CK-MB, myoglobin and cTT were measured at 0, 4, 8, 12, 16 and 20 h in the ICU. RESULTS: Five out of 15 ASBA patients had elevated CK, four of them presenting with an increase in CK-MB. Plasma cTT was normal in every patient, including those with CK and/or myoglobin elevation. At admission to the ICU, myoglobin and CK were positively correlated (r = 0.760; p < 0.001). No patient was intubated. There was no difference in clinical signs or symptoms, medical history, laboratory values or ECG in patients with or without CK elevation. CONCLUSION: Patients admitted to an ICU for ASBA may present with an elevation of plasma CK, CK-MB and myoglobin not related to any heart injury. CK and CK-MB are not good markers of myocardial injury in ASBA patients due to the multitude of potential confounders. Therefore, troponin should be measured instead.