[The MB Iso-enzyme of creatine phosphokinase in myocardial infarction (author's transl)]
Abstract:
CPK and its MB iso-enzymatic fraction were measured in 240 patients, 180 of whom suffered from myocardial infarction. MB iso-enzyme was expressed as a percentage of total CPK and a minimum figure of 4 per cent of MB isoenzyme was taken as indicative of a diagnosis of myocardial infarction. In the 180 patients with an infarction, the average MB level as a percentage of total CPK was 12.1 +/- 5.4 per cent. Five patients with a proven infarct had an MB iso-enzyme level of less than 4 per cent. Amongst the 60 patients without a myocardial infarction who were included in view of a pathological level of CPK, the average maximum level of MB was 1 +/- 2.5 per cent. Five of these 60 patients (false positives: 8.3%) had an MB iso-enzyme level of greater than 4 per cent. It is concluded that the estimation of MB iso-enzyme of CPK using a chromatographic technic is a highly valuable laboratory method for confirming or eliminating a diagnosis of myocardial infarction in the numerous clinical circumstances when such a diagnosis is difficult or even impossible on the basis of standard data.
Insights
Measuring creatine phosphokinase (CPK) MB iso-enzyme levels helps diagnose myocardial infarction. This chromatographic technique accurately confirms or excludes heart attacks, especially in complex cases.
Area of Science:
- Biochemistry
- Clinical Diagnostics
- Cardiology
Context:
- Myocardial infarction diagnosis can be challenging with standard data.
- Creatine phosphokinase (CPK) and its MB iso-enzyme are key cardiac biomarkers.
- Accurate diagnostic tools are crucial for timely patient management.
Purpose:
- To evaluate the diagnostic utility of CPK MB iso-enzyme estimation using chromatography for myocardial infarction.
- To determine the sensitivity and specificity of a 4% MB iso-enzyme threshold.
Summary:
- A chromatographic technique for CPK MB iso-enzyme measurement was assessed in 240 patients (180 with myocardial infarction).
- An MB iso-enzyme level of 4% of total CPK was used as the diagnostic cutoff.
- The method demonstrated high value in confirming or excluding myocardial infarction, with a false positive rate of 8.3%.
Impact:
- This laboratory method offers a reliable approach for diagnosing myocardial infarction, particularly in ambiguous clinical situations.
- Improved diagnostic accuracy can lead to more effective treatment strategies.
- The study supports the use of CPK MB iso-enzyme analysis in routine clinical practice.
