High-sensitivity Troponin-T

The U.S. FDA approved the first high-sensitivity troponin assay, the Roche Diagnostics Elecsys Troponin T (TnT) Gen 5 Stat test, in March 2017.

Yukon-Kuskokwim Delta Regional Hospital (YKDHR) adopted this high-sensitivity cardiac troponin-T (Hs-cTnT) assay on November 12, 2019.

The high-sensitivity and contemporary troponin-T assays can be distinguished by the units in which they are reported: Hs-cTnT is reported in ng/L whereas the contemporary assay (cTnT) is reported in ng/mL.

Cutoffs

Hs-cTnT is considered "positive" when above the gender-specific 99th percentile URL (upper reference range). Per eMail from Scott Cox (YKDHR Director of Diagnostic Services) on 11/10/2019, the following cutoff are recommended for our assay:

Positive Values

Women	>= 14 ng/L
Men	>= 22 ng/L

A delta (i.e. a change over time, either increase or decrease) >= 3 ng/L is considered positive for acute myocardial injury (AMI).

Per the ACC white paper (see below):

• A single Hs-cTnT >= 100 ng/L is diagnostic of AMI (in the appropriate clinical context).
  
• When chest pain has been present for >= 2 hours, a single Hs-cTnT < 6 ng/L has been reported to rule out AMI with essentially 100% negative predictive value.

Diagnostic Algorithm

Currently there are no experimentally validated diagnostic algorithms using Hs-cTnT. However, the internet contains several somewhat similar algorithms on reputable medical sites. In particular, the ACEP Webinar (see below, page 16) displays the following diagnostic algorithm:

Helpful Links

ACC (American College of Cardiology)

High-Sensitivity Cardiac Troponin in the Evaluation of Possible AMI (July 16, 2018)

SUMMARY: Fourth Universal Definition of Myocardial Infarction (Aug 25, 2018)

ACEP

Webinar: Incorporating High-Sensitivity Troponin into Your ED

MD Calc

HEART Score for Major Cardiac Events