Radioimmunoassay of serum myoglobin: evaluation and modification of a commercial kit and assessment of its usefulness for detecting acute myocardial infarction.

Abstract We evaluated a modified procedure for a commercially available myoglobin radioimmunoassay kit (Nuclear Medical Systems). Within-run and run-to-run precision was acceptable. Normal ranges were established and paralelism studies performed. Clinical usefulness was assessed in 100 consecutive patients admitted to our coronary-care facility. The determinations were done daily, along with creatine kinase and its isoenzymes, and lactate dehydrogenase and its isoenzymes. Fifty of the 100 patients ultimately were shown to have had acute myocardial infarction. Myoglobinemia was present in most of the patients with acute myocardial infarction, but information on its presence was less usefull clinically than was detection of creatine kinase isoenzyme MB.

Download Full-text

Comparable detection of acute myocardial infarction by creatine kinase MB isoenzyme and cardiac troponin I

Clinical Chemistry ◽

10.1093/clinchem/40.7.1291 ◽

1994 ◽

Vol 40 (7) ◽

pp. 1291-1295 ◽

Cited By ~ 197

Author(s):

J E Adams ◽

K B Schechtman ◽

Y Landt ◽

J H Ladenson ◽

A S Jaffe

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Creatine Kinase ◽

Cardiac Troponin ◽

Troponin I ◽

Characteristic Curve ◽

Cardiac Injury ◽

Cardiac Troponin I ◽

Creatine Kinase Mb ◽

Coronary Care

Abstract Although measurement of cardiac troponin I (cTnI) is, in some situations, more specific for detection of cardiac injury than is measurement of the MB isoenzyme of creatine kinase (MBCK), its sensitivity and specificity relative to MBCK for detection of myocardial infarction has not been established. Accordingly, we studied prospectively 199 consecutive patients admitted to the coronary care unit. Values of MBCK and cTnI mass were determined in all samples. Of the 188 patients admitted with a suspicion of acute myocardial ischemia, 89 were diagnosed as having an acute myocardial infarction on the basis of the patterns of MBCK values. Eighty-six of these patients also had increased cTnI (concordance, 96.6%); three did not. Of the patients diagnosed as without infarction, five with unstable angina and symptoms in the day(s) prior to admission had increased cTnI, for a cTnI specificity of 94.9%. Receiver operating characteristic curve analysis indicated that cTnI and MBCK had statistically indistinguishable diagnostic accuracies for the detection of acute myocardial infarction.

Download Full-text

Clinical evaluation of an immunoinhibition procedure for creatine kinase-MB.

Clinical Chemistry ◽

10.1093/clinchem/26.1.0150 ◽

1980 ◽

Vol 26 (1) ◽

pp. 150-152

Author(s):

D Obzansky ◽

J A Lott

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Creatine Kinase ◽

Sensitivity And Specificity ◽

Clinical Evaluation ◽

Creatine Kinase Isoenzyme ◽

Creatine Kinase Mb ◽

Diagnostic Sensitivity And Specificity ◽

Creatine Kinase Isoenzyme Mb

Abstract We have clinically evaluated the Dade "Cardiozyme" immunoinhibition procedure for determination of creatine kinase isoenzyme MB (CK-MG) in 71 patients who were suspected of having had an acute myocardial infarction. Electrophoresis for CK-MB was also carried out. On the basis of diagnostic sensitivity and specificity for myocardial infarction, we found the Dade procedure for CK-MB to be somewhat inferior to electrophoresis. In 11 patients for whom the time of infarction was known, we observed normal CK-MB results for two of them by both immunoinhibition and electrophoresis during the first 24 h, but subsequently could detect abnormal CK-MB results by both methods. Thus in some patients such data are not helpful for making a diagnosis in the first 24 h. The Dade procedure is easy to perform, but lacks sensitivity in the region of low CK-MB activity, requires a very stable spectrophotometer, is imprecise, and produces negative numerical results in patients without myocardial infarction.

Download Full-text

Diagnosis of acute myocardial infarction from two measurements of creatine kinase isoenzyme MB with use of nonparametric probability estimation.

Clinical Chemistry ◽

10.1093/clinchem/35.3.444 ◽

1989 ◽

Vol 35 (3) ◽

pp. 444-447 ◽

Cited By ~ 6

Author(s):

L H Bernstein ◽

I J Good ◽

G I Holtzman ◽

M L Deaton ◽

J Babb

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Creatine Kinase ◽

Bayes Factors ◽

Probability Estimation ◽

Posterior Odds ◽

Creatine Kinase Isoenzyme ◽

Time Of Admission ◽

Bivariate Probability ◽

Creatine Kinase Isoenzyme Mb

Abstract By using bivariate probability estimation for the diagnosis of acute myocardial infarction (AMI) we show how to overcome the difficulties encountered for patients whose clinical presentation is atypical and those encountered when multiple isoenzyme determinations are treated by univariate methods. We use the values for creatine kinase isoenzyme MB measured at the time of admission and 12 h later to estimate the Bayes factors in favor of AMI. The Bayes factors are compiled into a table that the clinician can use to estimate the posterior probability that a patient has AMI. The table of Bayes factors is based on data for a sample of 802 non-AMI patients and 180 AMI patients. Further to validate the method, we randomly chose 200 of the non-AMI and 50 of the AMI patients as an evaluation sample, then used the remaining 602 non-AMI and 130 AMI patients to recompute the Bayes factors. These Bayes factors were used to find the probability of AMI for each of the 250 patients in the evaluation sample. The method resulted in only one false positive and no false negatives. For the misclassified patient the measurements at admission and 12 h later were 1 and 11 U/L; the posterior odds were 15 to 1 in favor of AMI, but in fact the patient was non-AMI.

Download Full-text

Increased activity of creatine kinase isoenzyme MB in a theophylline-intoxicated patient.

Clinical Chemistry ◽

10.1093/clinchem/31.10.1741 ◽

1985 ◽

Vol 31 (10) ◽

pp. 1741-1742 ◽

Cited By ~ 2

Author(s):

R H Ng ◽

C Roe ◽

D Funt ◽

B E Statland

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Creatine Kinase ◽

Time Course ◽

Clinical Findings ◽

Creatine Kinase Isoenzyme ◽

Increased Activity ◽

Theophylline Intoxication ◽

Creatine Kinase Isoenzyme Mb

Abstract A 78-year-old woman had increased activities of creatine kinase (CK; EC 2.7.3.2) and CK-MB isoenzyme in her serum, associated with severe theophylline intoxication. The time course for CK-MB activity was similar to that from an acute myocardial infarction. Clinical findings, however, including electrocardiograms, did not support the diagnosis of myocardial infarction. We suggest caution in interpreting CK-MB results in severe theophylline intoxication.

Download Full-text