Troponin levels

• Become elevated within 2 - 3 hours after the onset of chest pain (50-60%)
• Peaks at 18-24 hours
• Remain elevated for up to 14 days
• Half-life of circulating troponin is ≈ 2 hours.
• Elevated troponin is found in 30-40% of patients with Unstable Angina.

High-sensitive troponin assays

While high-sensitivity cardiac troponin assays measure the same analyte as their predecessors, they are more precise in analytical sensitivity. A high-sensitive troponin test can measure lower levels of troponin in blood, obtaining limits of detection (LoD) in ranges that were previously undetectable. This allows for the measurement of troponin levels in normal healthy individuals. The high precision offers several advantages:

• Rapid diagnosis or exclusion of AMI within one hour—compared to 12 hours with previous troponin assays
• Confident results reporting due to a low coefficient of variation (CV—<10% at 99th percentile of the reference population; measurements are reproducible and indicate that rising and falling troponin patterns are due to a patient’s biology, not test imprecision)
• More accurate calculation of the 99th percentile upper reference limit (URL) with a 95% confidence interval
• An LoD that is in the single-digit ng/L range and markedly lower than the URL—determined by measuring troponin levels in a healthy reference population
• Sex-specific reference ranges to address troponin level differences in men and women
• Flexibility to use serum or plasma, depending upon the test