High Sensitivity Troponin Reference Values and Interpretation

Assay-Specific Reference Values

The American College of Cardiology recommends that the normal value for high sensitivity troponin (hs-troponin) is below the 99th percentile upper reference limit, which varies by assay type and sex, with common cutoffs being <14 ng/L for hs-cTnT and <26 ng/L for hs-cTnI 1, 2, 3
For high-sensitivity cardiac troponin T (hs-cTnT), the 99th percentile upper reference limit is generally established at 14 ng/L 1, 2
For high-sensitivity cardiac troponin I (hs-cTnI), the 99th percentile upper reference limit is approximately 26 ng/L when using the Abbott ARCHITECT assay 1, 2
The limit of detection varies among different hs-cTn assays, typically between 1 ng/L and 5 ng/L 4, 5

The American College of Cardiology states that a value above the 99th percentile does not automatically indicate myocardial infarction - serial measurements showing a rise and/or fall pattern are required 6, 7
For diagnosis of acute myocardial necrosis, evidence of a serial increase or decrease ≥20% is required if the initial value is elevated 6
For values below or close to the 99th percentile, evidence for acute myocardial necrosis is indicated by a change of ≥3 standard deviations around the initial value 6
Absolute changes in ng/L have higher diagnostic accuracy for AMI than relative changes 6, 7

The American College of Cardiology notes that solitary elevations of troponin should not be assumed to be due to myocardial infarction - many conditions can cause troponin elevation including tachyarrhythmias, heart failure, hypertensive emergencies, sepsis, and renal insufficiency 6, 7
Patients with end-stage renal disease frequently have elevated cardiac troponin levels even without clinical evidence of acute coronary syndrome 6
High-sensitivity assays can detect troponin in the blood of most healthy people, making serial changes more important than absolute values 6
The U.S. FDA has restricted reporting of hs-cTnT results to concentrations of 6 ng/L (limit of quantification) or greater, which affects some diagnostic protocols 1, 2

High-sensitivity troponin values are reported in nanograms per liter (ng/L) rather than the fractional results (ng/mL) used with conventional assays 8
This change results in whole numbers (e.g., 25 ng/L) rather than decimal values (0.025 ng/mL), which improves clarity and safety in interpretation 8