Immunochemical CK-MB assay for myocardial infarction

Area of Science:

• Clinical Chemistry
• Cardiology
• Biochemical Diagnostics

Background:

• Acute myocardial infarction (MI) diagnosis relies on sensitive and specific biomarkers.
• Creatine kinase-MB (CK-MB) isoenzymes are crucial cardiac markers.
• Evaluating novel diagnostic assays against established methods is essential for clinical practice.

Purpose of the Study:

• To compare the diagnostic efficiency of an immunochemical CK-MB (I-MB) assay with an electrophoretic CK-MB (E-MB) procedure.
• To assess the sensitivity, specificity, and overall efficiency of I-MB assay in patients with suspected acute MI.
• To evaluate the concordance between I-MB and E-MB assays.

Main Methods:

• A prospective study involving 215 patients with suspected acute MI.
• Serial assays of total creatine kinase (CK), lactic dehydrogenase (LD), CK-MB, and LD1 isoenzymes.
• Comparison of I-MB assay results with E-MB results at established decision values.
• Calculation of sensitivity, specificity, and test efficiency rates.

Main Results:

• The I-MB assay showed high intra-assay (2.05%) and inter-assay (7.2%) precision.
• Concordance between I-MB and E-MB was 94.4% (203/215 patients).
• At 10 U/L cut-off, I-MB was 95.5% sensitive and 95.3% specific for acute MI, outperforming E-MB (93.3% sensitivity, 94.7% specificity).
• Test efficiency was 95.3% for I-MB versus 94.4% for E-MB.

Conclusions:

• The immunochemical CK-MB assay is a highly efficient, sensitive, and specific diagnostic tool for acute MI.
• I-MB assay demonstrates comparable or superior diagnostic performance to the electrophoretic method.
• The findings support the utility of I-MB assay in the diagnostic protocol for suspected acute myocardial infarction.