CK-MB Results Research Articles

Prediction and Classification of COVID-19 Admissions to Intensive Care Units (ICU) Using Weighted Radial Kernel SVM Coupled with Recursive Feature Elimination (RFE).

Healthcare systems have been under immense pressure since the beginning of the COVID-19 pandemic; hence, studies on using machine learning (ML) methods for classifying ICU admissions and resource allocation are urgently needed. We investigated whether ML can propose a useful classification model for predicting the ICU admissions of COVID-19 patients. In this retrospective study, the clinical characteristics and laboratory findings of 100 patients with laboratory-confirmed COVID-19 tests were retrieved between May 2020 and January 2021. Based on patients’ demographic and clinical data, we analyzed the capability of the proposed weighted radial kernel support vector machine (SVM), coupled with (RFE). The proposed method is compared with other reference methods such as linear discriminant analysis (LDA) and kernel-based SVM variants including the linear, polynomial, and radial kernels coupled with REF for predicting ICU admissions of COVID-19 patients. An initial performance assessment indicated that the SVM with weighted radial kernels coupled with REF outperformed the other classification methods in discriminating between ICU and non-ICU admissions in COVID-19 patients. Furthermore, applying the Recursive Feature Elimination (RFE) with weighted radial kernel SVM identified a significant set of variables that can predict and statistically distinguish ICU from non-ICU COVID-19 patients. The patients’ weight, PCR Ct Value, CCL19, INF-β, BLC, INR, PT, PTT, CKMB, HB, platelets, RBC, urea, creatinine and albumin results were found to be the significant predicting features. We believe that weighted radial kernel SVM can be used as an assisting ML approach to guide hospital decision makers in resource allocation and mobilization between intensive care and isolation units. We model the data retrospectively on a selected subset of patient-derived variables based on previous knowledge of ICU admission and this needs to be trained in order to forecast prospectively.

Identifying early stages of doxorubicin-induced cardiotoxicity in rat model by 7.0 tesla cardiovascular magnetic resonance combining hematological and pathological parameters

PurposeTo identify early doxorubicin-induced cardiotoxicity by applying 7.0 T cardiac magnetic resonance (CMR) combined with creatine kinase isoenzymes (CKMB) from rat models, using pathological results as a reference standard. MethodsThe 48 male rats included in the study were divided into a doxorubicin (DOX) group (n = 32) and a control group (n = 16). Each group was further divided into four subgroups according to the interval weeks between the first administration and CMR examination. DOX group and the controls were injected with DOX (2.5 mg/kg) or physiological saline (2.5 mg/kg) through vena caudalis weekly. The rats in first subgroup received 4 weekly injections and were sacrificed after CMR examination at week 4. Rats in the second, third and fourth DOX or control subgroups underwent 6 weekly injections and were sacrificed after CMR examination at weeks 6, 8 and 10, respectively. The conventional cardiac function parameters, myocardial strain, standardized myocardial T2 value, late gadolinium enhancement, CKMB and pathological results of each rat were analyzed. ResultsThe LV mass index was reduced and CKMB was increased in the first subgroup (week 4), global circumference strain was decreased and normalized myocardial T2 relaxation time was prolonged in the second subgroup (week 6). At these early point of time, LVEF remained unaffected. Myocardial fibrosis was observed in the third and fourth subgroups (in week 8 and 10, respectively) and the collagen volume fraction was significantly negatively correlated with the LVEF and myocardial strain. ConclusionsCMR can be used to identify doxorubicin-induced cardiotoxicity at early stage, with the LV mass index, global circumference strain, normalized myocardial T2 relaxation time as the early markers. CKMB can indicate the optimal timing for CMR examination of chemotherapy recipients to improve medical efficiency. Myocardial fibrosis persists in the advanced stage of doxorubicin-induced cardiotoxicity which comprises the main cause of LV dysfunction.

Comparison of the Efficacy of Danhong Injections at Different Time-points During the Perioperative Period of Acute Myocardial Infarction: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Objectives: Danhong injections (DHI) are widely used in the treatment of acute myocardial infarction (AMI). As there are no guidelines for the timing of DHI in the peri-percutaneous coronary intervention (PCI) period for AMI, we investigated the effects of DHI timing. Methods: We reviewed reports published before September 30, 2020 in PubMed, embase, the Cochrane Central Register of Controlled Trials, the Chinese BioMedical database, Chinese VIP database, Wanfang database, and Chinese National Knowledge Infrastructure database. Only randomized controlled trials of DHI with percutaneous coronary intervention for AMI were included. Methodological quality was assessed using the Cochrane evaluation manual 5.3.3 criteria. A meta-analysis was performed, and forest plots were drawn. Results: We included 23 studies which all revealed that patients in DHI groups had better efficacy than control groups. Subgroup analysis revealed that DHI administered intraoperatively and continued postoperatively was more effective in increasing left ventricular ejection fraction when compared to other time-points (p < 0.001). The pre- and intraoperative use of DHI could improve reflow more effectively than conventional treatment, while the effect was not significant in the postoperative intervention study (p = 0.654). The 16 postoperative interventions revealed that the effect of DHI at 14 days was better than that at 7 and 10 days for hs-CRP (p = 0.013), the 10-days treatment produced better results for CK-MB than for the other treatments (p < 0.001) and a dosage of 30 ml proved most effective for IL-6 (p < 0.001). Conclusion: DHI proved to be superior to conventional Western medicine in reducing the incidence of adverse cardiac events, promoting reperfusion, improving cardiac function, reducing inflammatory factors, and protecting the myocardium. DHI should be administered early in the perioperative period and continued postoperatively because of its ability to improve cardiac function. Furthermore, in the PCI postoperative, 30 ml is recommended to inhibit IL-6 levels, for patients with high hs-CRP, a course of 14 days is most effective, for patients with obvious abnormalities of CK-MB, a 10-days course of treatment is recommended. However, due to the limited number and quality of the original randomized controlled trials, our conclusions need large, multi-centre RCTs to validation.

Association between prostate specific antigen levels and coronary artery angioplasty.

Introduction: Prostate-specific antigen (PSA) is a protein, whose serum levels changes during various physiologic and pathologic situations. Recently, the relationship between PSA and cardiologic disorders has been assessed. Objectives: The purpose of this study was to assess the association of percutaneous coronary intervention (PCI) complications with PSA serum levels. Patients and Methods: In this study, 100 eligible patients undergoing PCI were included. The total PSA serum values were analyzed pre- and post-procedure. The association between PSA levels with age, gender, inflammatory (C-reactive protein [CRP] and white blood cell [WBC]), cardiogenic (troponin, CK-MB, echocardiography and angiography results), and nephrology (creatinine) properties was investigated. Results: Changes in the level of PSA pre- and post-PCI was not significant (P=0.2). However, based on the pathology, patients with acute coronary syndrome (ACS) had a significant difference in the levels of PSA compared to cases of stable ischemic heart disease (SIHD) (P=0.008). Moreover, the effect of gender on the changes in PSA level following PCI was conclusive. There was no association between the direct effect of PCI parameters or PCI complications on PSA level changes. Conclusion: The results showed that PSA levels were affected by the etiology of cardiac disorders instead of therapeutic methods like PCI.

The clinical utility of CK-MB measurement in patients suspected of acute coronary syndrome

BackgroundThis study aims to assess the clinical utility of CK-MB measurement in patients suspected of acute coronary syndrome (ACS). MethodsAll CK-MB and troponin T measurements performed <1h apart during the study period were obtained and analyzed for concordance. A total of 1214 cases with discordant biomarkers results were found. Retrospective review of electronic health records (EHRs) was performed to assess the clinical impact, if any, of the discordant biomarkers results. ResultsIn 401 cases, CK-MB concentrations were increased whereas troponin T concentrations were negative at <0.01ng/ml. In this group, clinical interpretations included, rhabdomyolysis, demand ischemia, and drug intoxication. No additional investigations for ACS were conducted in this group. Among the remaining 813 cases, troponin T concentrations were increased in the presence of a normal CK-MB result. In this group, the discordant normal CK-MB lowered suspicion for ACS in only 22 cases (2.7%). Most common interpretations for isolated positive troponin were demand ischemia and impaired renal function. In most cases, discordant CK-MB results were not considered a significant finding. ConclusionsIn the setting of suspected ACS, CK-MB has limited clinical impact when contemporary troponin assay results are available.

A rare cause of elevated CK: quality investigation requires analytical understanding

Introduction Creatine kinase (CK) is usually used to detect and monitor muscle damage, particularly skeletal and cardiac. The three dimeric isoforms (CK-MM, CK-MB and CK-BB) have different tissue distributions. Clinical presentation A 7-year-old girl presented with severe pain and tenderness in the right hip after a minor fall. Results Right hip X-ray showed femoral neck fracture and diffuse sclerosis in the sacrum, pelvis and femur suggesting osteopetrosis. Calcium, phosphate, PTH, electrolytes and creatinine were normal. Lactate dehydrogenase was 667* U/L (100–200), AST 89* U/L (20–60). Creatine kinase (CK) was 615* U/L (0–190) and CK-MB (immunoinhibition method) was 760* U/L (0–24). CK isoenzyme electrophoresis done due to the discrepant total and CK-MB results showed CK-BB 87% with CK-MB Discussion In osteopetrosis, CK-BB is released by the defective osteoclasts. However the CK-MB immunoinhibition assay assumes all non-M activity is from CK-MB and therefore the result is multiplied by 2 to give ‘total MB’ activity. In conditions with elevated CK-BB, this technique would give falsely high ‘CK-MB’. This is overcome by using immu-noassay measuring CK-MB by mass or isoenzyme electro-phoresis. Conclusion The quality of biochemical investigations can be very significantly impacted by the appropriateness of the methodology employed to investigate a specific condition. Analytical understanding is crucial.

Outcomes associated with small changes in normal-range cardiac markers

Introduction Troponin concentrations rising above an institutional cutpoint are used to define acute myocardial necrosis, yet it is uncertain what outcomes are associated with fluctuations in troponin that do not exceed this level. We evaluate the association between troponin fluctuations below an institutional upper limit of normal and acute coronary syndrome (ACS). Materials and methods This was a post hoc analysis of the Internet tracking registry of ACS (i*tr ACS), which describes patients presenting to emergency departments (EDs) with suspected ACS across the spectrum of risk. Patients were included in this registry if they were at least 18 years old and had suspected ACS at the time of their ED visit. Inclusions in this analysis required that patients had at least 1 cardiac marker (creatine kinase-MB [CK-MB], troponin T, or troponin I) drawn twice within 6 hours of presentation, with both measures being below the institution's upper limit of normal. A marker change was defined as either an increase or decrease that exceeded 15% of the institutional upper limit of normal. Acute coronary syndrome was defined as a positive stress test, documented myocardial infarction, coronary revascularization, or death within 30 days of their ED admission. Results Of 17 713 patient visits, 2162 met inclusion and exclusion criteria. There were 1872 patient visits with 2 troponin results and 1312 with 2 CK-MB results. Patient visits with increasing troponin had increased odds of ACS compared with those with stable troponin levels (odds ratio, 3.6; 95% confidence interval, 1.4-9.2). Changing CK-MB and decreasing troponin were not associated with increased odds of ACS. Conclusions Small increases in troponin concentration below the upper limit of normal are associated with increased odds of ACS.

Clinically effective CK-MB reporting

The clinical utility of measuring the Muscle Brain (MB) isoenzyme of creatine kinase (CK) in the diagnosis of myocardial injury is well established. CK/CK-MB measurement in combination or CK-MB alone is widely used and reporting the results of CK-MB in absolute unit is the common current practice. CK-MB is widely measured by "Immunoinhibition" in India, which gives falsely elevated CK-MB results in the following circumstances: Central nervous system damage, childbirth, macro CK-immunoglobulin complex, in patients with carcinoma of various organs, such as prostate carcinoma and other adenocarcinomas. But, reporting %CK-MB rather than the absolute CK-MB results assists in detection of macroCK (or CK variants), associated proliferative and autoimmune pathologies and their prognosis.

Comparison of Site-Reported and Core Laboratory-Reported Creatine Kinase-MB Values in Non–ST-Segment Elevation Acute Coronary Syndrome (from the International Trial SYNERGY)

The effect of nonstandardized creatine kinase (CK)-MB assays on the assessment of myocardial infarction (MI) end points in multicenter international trials has not been evaluated. We compared the site-reported and corresponding core laboratory CK-MB measures from 5 countries participating in the Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial. Samples for CK-MB were collected locally, with corresponding samples sent to a core laboratory at enrollment and after recurrent ischemic events, percutaneous coronary intervention, or coronary artery bypass grafting. The measured values were compared to the reported assay upper limits of normal (ULN) used at the site (or core laboratory for the core laboratory samples). The CK-MB results were available locally and from the core laboratory for 913 patients, constituting 4,693 time-matched laboratory values. The agreement between the core and site laboratory CK-MB/ULN ratio was moderate (concordance correlation coefficient 0.45) and varied considerably by geographic location and site. The CK-MB values were elevated (>or=2 times the ULN) by the core laboratory but normal (<2 times the ULN) by local standards in 708 instances (15%). There were 162 MI end points according to the core laboratory values versus 91 MI end points using the site-reported CK-MB data (kappa statistic 0.48). Compared with patients with no MI by the core or site laboratory values, patients with MI, as determined by both the core and the site laboratories, had significantly lower unadjusted 1-year survival rates (80.6% vs 93.5%, p <0.0001). Patients with MI, as determined by the core laboratory but not by the site laboratory, showed a trend toward a lower 1-year survival rate (89.8% vs 93.5%, p = 0.20). In conclusion, a substantial variation in CK-MB ratios and MI outcomes between the site and core laboratory data was observed in the SYNERGY trial. More MI outcomes were identified by the core laboratory, and patients with MI as defined by core laboratory data had lower 1-year survival, making these events potentially clinically important.

A Rapid Point-of-Care Cardiac Marker Testing Strategy Facilitates the Rapid Diagnosis and Management of Chest Pain Patients in the Emergency Department

We compared a rapid, point-of-care multimarker protocol with a single and serial troponin I (TnI)-only protocol in 5,244 patients admitted to the emergency department with chest pain. The diagnosis of acute myocardial infarction (AMI) was based on a doubling myoglobin level accompanied by at least a 50% increase in the creatine kinase (CK)-MB level with no detectable TnI; a doubling of myoglobin level together with any detectable TnI; or a TnI level of 0.4 ng/mL (0.4 microg/L) or more, irrespective of myoglobin or CK-MB results. By using these new criteria, 145 of 148 cases were positive for AMI (positive predictive value [PPV], 92.4%) and 3 were negative, which were also negative by the core laboratory TnI assay. Twelve confirmed non-AMI cases were positive by the new protocol, with 10 of 12 confirmed by the core laboratory as positive for TnI. The negative predictive value (NPV) was 99.9% the overall diagnostic accuracy was 99.7%. The TnI-only protocol had a sensitivity of 68.2% with an NPV of 99.1%. With lower TnI-only cutoffs, 4 patients had false-negative results, and a PPV of 36.4% was observed. Our rapid multimarker protocol seems superior to a TnI-only approach for rapidly triaging patients with chest pain or AMI.

Discordant Cardiac Biomarkers: Frequency and Outcomes in Emergency Department Patients With Chest Pain

We evaluate associations between pairs of discordant cardiac biomarkers (positive MB band of creatine kinase [CKMB] with negative creatine kinase, positive CKMB with negative cardiac troponin, and positive troponin with negative CKMB) and the presence of acute coronary syndromes in emergency department (ED) chest pain patients. This was a secondary analysis of a prospective registry. Data were obtained from the multicenter Internet Tracking Registry of Acute Coronary Syndromes, which included 17,713 ED visits for possible acute coronary syndrome between June 1999 and August 2001. First visits and first ED cardiac biomarker results from the 9 sites, 8 in the United States and 1 in Singapore, were included. Subjects were excluded for incomplete information or an initial ECG consistent with ST-segment elevation myocardial infarction. Acute coronary syndrome was defined by diagnosis-related group code indicating myocardial infarction, positive invasive or noninvasive diagnostic testing, revascularization, or death during hospitalization or within 30 days. Of 8,769 eligible patients, 1,614 (18.4%) had acute coronary syndrome. The CKMB and cardiac troponin results were discordant in 7% of patients (CKMB+/cardiac troponin-, 4.9%, CKMB-/cardiac troponin+ 2.1%), whereas increased CKMB with normal creatine kinase levels occurred in 239 (3.1%) patients. The unadjusted odds ratios with 95% confidence intervals for acute coronary syndrome in patients with and without discordant markers were: CKMB+/CK- 5.7 (4.4-7.4), CKMB+/CK+ 4.4 (3.6-5.2), CKMB-/cTn+ 4.8 (3.4-6.8), CKMB+/cTn- 2.2 (1.7-2.8), CKMB+/cTn+ 26.6 (18.0-39.3). For the group with cardiac troponin, the reference category was negative troponin and negative CKMB; for the group with creatine kinase, the reference category was negative CKMB but either a positive or negative creatine kinase. Among the spectrum of ED patients with chest pain, an increased CKMB level with a normal creatine kinase level identifies patients at increased risk for acute coronary syndrome. Similarly, an increased troponin level regardless of CKMB level and an increased CKMB level regardless of troponin level identify patients at higher risk for acute coronary syndrome than those with uniformly normal cardiac biomarker levels. Our data suggest that discordant cardiac biomarkers may identify patients at increased risk for acute coronary syndrome.

Elevated creatine kinase-MB with normal creatine kinase predicts worse outcomes in patients with acute coronary syndromes: Results from 4 large clinical trials

The degree to which elevated creatine kinase (CK)-MB in the presence of normal CK is predictive of outcome is not well understood despite having been studied for decades. This analysis examined whether normal CK with elevated CK-MB in patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS) is an independent predictor of worse outcomes. A concomitant goal was to contribute insight to the debate over how patients with NSTE ACS should be managed. Data for 25,960 patients from the GUSTO IIb, PARAGON A and B, and PURSUIT trials were analyzed. Of these patients, 6402 were excluded from primary analysis because of missing (unmeasured) biomarkers. Patients with complete laboratory data (n = 19,558) were grouped by CK and CK-MB results. To confirm the primary analysis results, data from patients with missing biomarkers were used in an imputation model. Patients were categorized in 1 of 4 groups: normal CK + normal CK-MB; normal CK + elevated CK-MB; elevated CK + normal CK-MB; or elevated CK + elevated CK-MB. For the primary outcome, 180-day death, or myocardial infarction, Kaplan-Meier estimates were 14.9%, 20.8%, 14.5%, and 18.2%, respectively. Regardless of total CK, elevated CK-MB was associated with a 25% to 49% increased relative risk of worse outcomes. Findings from the analyses were verified by the multivariable model. CK-MB remains a reliable marker for myocardial necrosis and a strong predictor of worse prognosis. All patients with ACS should have CK-MB measurement to search for cardiac ischemia. Patients with elevated CK-MB should receive aggressive management commensurate with their increased risks.

Impact of redefining acute myocardial infarction on incidence, management and reimbursement rate of acute coronary syndromes

Background Although redefinition for acute myocardial infarction (AMI) has been proposed few years ago, to date it has not been universally adopted by many institutions. The purpose of this study is to evaluate the diagnostic, prognostic and economical impact of the new diagnostic criteria for AMI. Methods Patients consecutively admitted to the emergency department with suspected acute coronary syndromes were enrolled in this study. Troponin T (cTnT) was measured in samples collected for routine CK-MB analyses and results were not available to physicians. Patients without AMI by traditional criteria and cTnT ≥ 0.035 ng/mL were coded as redefined AMI. Clinical outcomes were hospital death, major cardiac events and revascularization procedures. In-hospital management and reimbursement rates were also analyzed. Results Among 363 patients, 59 (16%) patients had AMI by conventional criteria, whereas additional 75 (21%) had redefined AMI, an increase of 127% in the incidence. Patients with redefined AMI were significantly older, more frequently male, with atypical chest pain and more risk factors. In multivariate analysis, redefined AMI was associated with 3.1 fold higher hospital death (95% CI: 0.6–14) and a 5.6 fold more cardiac events (95% CI: 2.1–15) compared to those without AMI. From hospital perspective, based on DRGs payment system, adoption of AMI redefinition would increase 12% the reimbursement rate [Int $3552 per 100 patients evaluated]. Conclusions The redefined criteria result in a substantial increase in AMI cases, and allow identification of high-risk patients. Efforts should be made to reinforce the adoption of AMI redefinition, which may result in more qualified and efficient management of ACS.

Prognostic value of isolated troponin elevation across the spectrum of chest pain syndromes

The risk of death or recurrent myocardial infarction (MI) in patients with chest pain and baseline isolated troponin elevation is unclear. To determine the early and short-term risk of death or MI associated with isolated troponin elevation across a spectrum of chest pain syndromes, we used baseline creatine kinase (CK)-MB and troponin data from the Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON) B troponin substudy, the Global Utilization of Strategies To Open Occluded Coronary Arteries (GUSTO) IIa troponin substudy, and the Chest Pain Evaluation by Creatine Kinase-MB, Myoglobin, and Troponin I (CHECKMATE) study. Patients were grouped into 1 of 4 categories based on marker status (troponin-positive/CK-MB-positive, troponin-positive/CK-MB-negative, troponin-negative/CK-MB-positive, or troponin-negative/CK-MB-negative). The adjusted odds of death or MI occurring at 24 hours and 30 days was assessed by baseline marker status using multivariable logistic regression, with the group negative for both markers used as the reference. Patients who were positive for both markers had the highest odds of the 24-hour and 30-day end point. The adjusted odds of the 30-day end point for patients with isolated troponin elevation were 1.3 (95% confidence interval 0.7 to 2.3) and 4.8 (95% confidence interval 1.4 to 16.0) for high- and low-risk patients, respectively. The risk for 24-hour and 30-day death or MI with isolated positive CK-MB results was lower than with isolated positive troponin results, and it was not significantly greater than if the 2 markers were negative. For patients with high- and low-risk chest pain, baseline troponin elevation without CK-MB elevation was associated with increased risk for early and short-term adverse outcomes. This suggests that these patients should be admitted to the hospital and monitored in either an intensive care or step-down unit.

Troponin I as expression of myocardial damage after major vascular surgery

In the perioperative period different levels of Troponin I (TnI) increase allow the identification of different severity degrees of myocardial damage [1]. Aim of the present study was to verify the correlation of TnI increase with clinical, ECG and Echo TT data and with the stratification of risk in patients submitted to major vascular surgery. A prospective observational study was performed on 51 patients submitted to major vascular surgery and then admitted to ICU. Preoperative measurements of TnI, CK-MB isoform, ECG and Echo TT were obtained. Then blood samples for TnI and CK-MB were obtained every 6 hours for 72 hours after surgery and then once daily. Twelve-leads ECG was registered daily. A new echocardiogram was obtained 48-72 hours after surgery. According to our laboratory and to NACB [2], two cut-off values for TnI were used as follows: normal values = 0.11 to 1.5 ng/ml. Patients were then subdivided into three groups in relation to TnI levels: Group T0 = normal values ( 0.11 to 1.5 ng/ml. In every group TnI values were related to CK-MB, ECG and echo TT results. Patients were reassessed 3 months after surgery by means of telephone survey, ECG, echo TT and clinical evaluation.

A proposed strategy for utilization of creatine kinase-MB and troponin I in the evaluation of acute chest pain

In recent years, cardiac troponins have attracted great interest as a marker for myocardial injury. However, there are limited data on strategies for use of creatine kinase (CK)-MB and troponin I (cTnI) in clinical practice. We sought to develop a testing strategy using prospectively collected clinical data including serial CK-MB and cTnI levels from 1,051 patients aged ≥30 years admitted to a teaching hospital for acute chest pain. Diagnostic performance was evaluated for peak values of CK-MB and cTnI obtained during the first 24 hours for the combined end point of acute myocardial infarction and/or major cardiac events within 72 hours. The overall diagnostic accuracy was similar for both cardiac markers alone, and for the combination of cTnI and CK-MB (receiver-operating characteristic curve 0.84, 0.86, and 0.87, respectively). In the multivariate analysis, models including cardiac markers showed that both CK-MB and cTnI added information to clinical data to predict the combined end point, but cTnI added significantly less. Using recursive partitioning analysis, we developed a strategy that would restrict routine cTnI use to patients with normal CK-MB results and findings on the electrocardiogram consistent with ischemia. This strategy would divide patients with suspected myocardial ischemia into 4 groups with risks for the combined end point of 4%, 13%, 26%, and 85%. Thus, cTnI adds information to CK-MB mass and clinical data for predicting major cardiac events, but this contribution is mainly in patients with evidence of myocardial ischemia on their electrocardiograms.

Clinical evaluation of the CARDIAC STATus, a rapid immunochromatographic assay for simultaneous detection of elevated concentrations of CK-MB and myoglobin in whole blood.

We studied the performance of the CARDIAC STATus, a new rapid, easy to perform qualitative whole blood bedside test for detection of elevated CK-MB and myoglobin in the emergency room. Blood samples from 182 consecutive patients with chest pain were drawn on admission and at five and seven hours after the onset of symptoms. The CARDIAC STATus tests were performed by coronary care unit nurses and, independently, by a trained laboratory technician. The results were compared with quantitative assays for CK-MB mass and myoglobin. At the end of the study, a second test series using a new lot number of cartridges was performed on the same blood samples because of possible elution buffer contamination. Nurses produced more false negative results than the technician (CK-MB 43 vs. 27 %, p=0.01, myoglobin 31 vs. 13%, p<0.0001), but the technician produced more false positive myoglobin results (9.3 vs. 5.5%, p=0.0001). In the second test series, the nurses produced significantly fewer false negative tests both for CK-MB (19%, p<0.0001) and myoglobin (13%, p=0.0002). The false negative rate for the technician was not different between the first and the second test series. The CARDIAC STATus yields a substantial number of false negative results both for CK-MB and myoglobin when compared to a quantitative assay, and therefore at present has limited value for ruling out an acute myocardial infarction.

Ectopic Production of Creatine Kinase MB: Updated Evaluation by Mass Assays

There have been several reports of apparently high concentrations of creatine kinase (CK)-MB in the sera of cancer patients (1)(2)(3)(4). In several of these cases, the high activity resulted from the presence of macro CK types 1 and 2 (5). False-positive results for CK-MB can occur if nonspecific assays such as immunoinhibition are used (6). These atypical isoenzymes are not inhibited by anti-CK-B antibodies, and high apparent CK-MB activities are produced. Macro CK type 1 (CK-BB bound to IgG) migrates between CK-MM and -MB, whereas type 2 (polymeric mitochondrial CK) migrates cathodic to CK-MM and can be readily differentiated from CK-MB by electrophoresis (7). However, macro CK-BB linked to IgA can comigrate with CK-MB, and false-positive detection of MB is possible even with electrophoresis (8). Annesley and McKenna (9) published the one clear case of ectopic CK-MB production by a tumor, by demonstrating high concentrations of CK-MB in homogenized tumor tissue and ruling out the presence of macro CK forms by heat stability tests. We describe a second case in which persistently high concentrations of CK-MB were detected in a patient with metastatic cancer. CK isoforms, myoglobin, lactate dehydrogenase isoenzymes, and cardiac troponins T and I were used to rule out the presence of acute myocardial injury. A 71-year-old white man with a past medical history of coronary artery disease, acute myocardial infarction (AMI), hypertension, congestive heart failure, cerebrovascular accident, carotid stenosis, and atrial fibrillation presented to the Hospital of St. Raphael with a 4-day history …

Prognostic Value of Cardiac Troponin T After Noncardiac Surgery: 6-Month Follow-Up Data

Objectives. We sought to evaluate the prognostic significance of cardiac troponin T (TnT) serum levels after noncardiac surgery.Background. Cardiac TnT has been found to be a marker for myocardial injury, but elevations of TnT are common in patients undergoing noncardiac surgery without clinical evidence of severe ischemia.Methods. We studied 772 patients who underwent major noncardiac procedures and did not have major cardiovascular complications during their inpatient course. Total serum creatine kinase (CK) and cardiac TnT were measured according to a protocol that included sampling in the recovery room and during the next 2 days. A 6-month follow-up interview was performed for 722 (94%) of the patients.Results. Elevated cardiac TnT and CK-MB results were detected for 92 (12%) and 211 (27%) patients, respectively. During the follow-up period, there were 19 (2.5%) major cardiac complications, including 14 cardiac deaths, 3 nonfatal myocardial infarctions and 2 admissions for unstable angina. Compared with patients with cardiac TnT values <0.1 ng/ml, patients with elevated TnT had a relative risk for cardiac events of 5.4 (95% confidence interval: 2.2 to 13, p = 0.001), whereas CK-MB was not correlated with postdischarge cardiac events. In multivariate logistic regression analysis adjusting for preoperative clinical and CK-MB data, a cardiac TnT value >0.1 ng/ml was an independent correlate of cardiac events (adjusted odds ratio 4.6, p < 0.05). This correlation was a function of the relation of elevated TnT levels with postoperative in-hospital congestive heart failure and new sustained arrhythmias, suggesting that elevated postoperative TnT levels detected myocardial ischemia during these clinical events.Conclusions. We conclude that an abnormal TnT level in patients undergoing noncardiac surgery may be a useful marker of ischemic disease and a predictor of 6-month prognosis.(J Am Coll Cardiol 1997;29:1241–5)

Evaluation of the cardiac STATus ™ CK-MB/Myoglobin Card Test to diagnose acute myocardial infarctions in the ED

A study was undertaken to evaluate a Card Test called “Spectral Diagnostics Inc Cardiac STATus ™ CK-MB/Myoglobin” (Toronto, Canada), which is distributed by Dade International Inc, Miami, FL, for the simultaneous qualitative determination of CK-MB and myoglobin levels in human serum. The Card Test is advertised by the manufacturer as an aid in diagnosing acute myocardial infarction (AMI) in the emergency department (ED). Fifty-eight consecutive serum samples were obtained from 25 patients being evaluated for AMI in an ED. Qualitative CK-MB and myoglobin results from the Card Test were compared with quantitative CK-MB and myoglobin results using the ACS-180 instrument (Ciba Corning Diagnostics, Medfield, MA) and Stratus® Ilntellect T (Dade International Inc, Miami, FL), respectively. Qualitative results from the STATus ™ CK-MB/Myoglobin Card Test were similar, diagnostically, to quantified results using these automated instruments.