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 IIntellect 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.

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions.

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB.

We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.

Creatine kinase MB in cases of skeletal muscle trauma.

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.