Biological variation of cardiac markers: analytical and clinical considerations

Area of Science:

• Clinical Biochemistry
• Biomarker Analysis
• Analytical Chemistry

Background:

• Cardiac marker interpretation often relies on population-based reference values.
• Understanding biological variation is crucial for accurate clinical decision-making.
• Individual variability in biomarkers can impact diagnostic sensitivity.

Purpose of the Study:

• To estimate analytical and biological variation components for key cardiac markers.
• To assess the utility of population-based reference values versus individual variability.
• To establish objective criteria for monitoring cardiac marker changes in individuals.

Main Methods:

• Quantification of serum total creatine kinase (TCK) activity, CK-MB activity, CK-MB mass, and myoglobin concentration.
• Analysis of within-subject and between-subject variation over a 5-day period in healthy subjects.
• Comparison of analytical goals with biological variation to assess methodological needs.

Main Results:

• Significant within-subject and between-subject variation was observed for most cardiac markers.
• Methodological improvements are recommended for all markers except CK-MB mass.
• High individual variability was noted for all cardiac markers, questioning the universal applicability of reference values.
• Critical differences for serial result changes vary significantly between markers.

Conclusions:

• Conventional population-based reference values may be insufficient for interpreting individual cardiac marker results.
• The marked individuality of cardiac markers necessitates personalized monitoring strategies.
• Objective criteria derived from biological variation data can enhance the monitoring of individuals.