High Sensitivity Cardiac Troponin T

1. See Also
   1. Troponin
   2. Troponin I
   3. Troponin T
   4. Serum Cardiac Markers
2. Background
   1. Not yet available in United States as of 2013
3. Efficacy: Where negative hs-cTnT <3 ng/L
   1. Test Sensitivity: 100%
   2. Test Specificity: 34%
   3. Positive Predictive Value: 25%
   4. Negative Predictive Value: 100%
4. Advantages
   1. Highly sensitive assays are 1,000 to 10,000 more sensitive than older assays (measured in pg/ml instead of ng/ml)
   2. Test Sensitivity is considerably better (97% sensitive) with high sensitivity assays (fewer False Negatives, NPV 99.1%)
   3. Less imprecision at discriminatory values (i.e. abnormal values are highly reproducible on repeat measurement)
   4. Abnormal rise is detected more quickly than with older assays
   5. Time to run high sensitivity assay is shorter
5. Disadvantages
   1. Significantly worse Test Specificity than with older assays (with significantly higher False Positive Rate)
      1. See Troponin for False Positive causes
6. Protocol
   1. hs-Troponin at 0 hours (presentation)
   2. hs-Troponin at 3 hours
      1. Markedly elevated baseline Troponin
         1. Discriminatory Troponin Increase at 3 hours: 20% over hsTn at time 0
      2. Near normal range baseline Troponin
         1. Discriminatory Troponin Increase at 3 hours: 50% over hsTn at time 0
   3. hs-Troponin at 6 hours
      1. Indicated if hsTn fails to reach discriminatory levels at 3 hours despite high clinical suspicion of ACS
   4. References
      1. Newby (2012) J Am Coll Cardiol 60(23): 2427-63 [PubMed]
7. References
   1. Lazarides (2013) Crit Dec Emerg Med 27(11): 2-8
   2. Body (2011) J Am Coll Cardiol 58(13): 1332-9 [PubMed]
   3. Mueller (2016) T Ann Emerg Med 68(1): 76-87 +PMID: 26794254 [PubMed]