IFCC Task Force Recommendations
Supports 99th Percentile
- 99th percentile cut-off universally endorsed
- Determined in a healthy population for male and female
- Derived from peer-reviewed literature, or manufacturer
- Analytical precision should be ≤ 10% CV
Defines High-Sensitivity Troponin
High-sensitivity refers to the assay's performance characteristics, not a difference in the form of cardiac troponin being measured
- %CV at the 99th percentile should be ≤10%1
- Measureable concentrations below the 99th percentile should be attainable with a concentration above the assay's LoD for at least 50% of healthy individuals1
- The guidelines have been extended on this second point by requiring both men and women individually attain measurable concentrations, with at least 50% measurable concentrations above the assay's LoD.2
1) Apple F., Sandoval Y., Jaffe A., and Ordonez-Llanos J. Cardiac Troponin Assays: Guide to Understanding Analytical Characteristics and Their Impact on Clinical Care. Report of the IFCC Task Force on Clinical Applications of Cardiac Biomarkers. Clinical Chemistry 63:01 (2016) ; Not available for sale in the U.S. Product availability varies by country
2) Alan H.B. Wu, Clinical Chemistry 64:4 645 -655 (2018)
2020 ESC Guidelines for the Management of Acute Coronary Syndromes in Patients Presenting Without Persistent ST-segment Elevation*
Due to the higher sensitivity and diagnostic accuracy for the detection of MI at presentation, the time interval to the second cardiac troponin assessment can be shortened to 0-1h or 0-2h with the use of hs-cTn assays. This has been derived and well-validated in large multicentre diagnostic studies using central adjudication of the final diagnosis.
Optimal thresholds for rule-out were selected to allow for a minimal sensitivity and NPV of 99%. Optimal thresholds for rule-in were selected to allow for a minimal positive predictive value (PPV) of 70%. The algorithms were developed in large derivation cohorts and then validated in large independent validation cohorts (APACE, High STEACS, HIGH US).
(*) European Heart Journal (2020) 00, 179 ESC GUIDELINES NSTE-ACS doi:10.1093/eurheartj/ehaa575
Additional sources:
Boeddinghaus J, et al. Clin Chem. 2018;64:1347-1360. (APACE)
Chapman AR, et al. Heart 2018;0:1 -7. doi:10.1136/heartjnl-2018-314093. (High STEACS)
Nowak R, et al.: Results From the HIGH-US Study, https://doi.org/10.1016/j.annemergmed.2019.12.008. (HIGH US)