Effective May 02, 2022, Clinical Pathology Laboratories is pleased to announce the conversion of troponin testing from the current troponin T assay to the enhanced generation 5 cardiac troponin T (Roche, cTnT GEN5) for the comprehensive evaluation of AMI. The new assay is a high-sensitivity cardiac troponin that enables more sensitive and precise detection at low troponin concentrations.
Troponin T (TnT) is a component of the contractile apparatus of the striated musculature. Although the function of TnT is the same in all striated muscles, the cardiac isoform of TnT originating exclusively from the myocardium (cardiac TnT, molecular weight 39.7 kDa) clearly differs from skeletal muscle TnT. As a result of its high tissue-specificity, cardiac troponin T (cTnT) is a cardio-specific, highly sensitive marker for myocardial damage.
Rapid, precise, and accurate detection of clinical, imaging, electrophysiological, and biomarker findings are the foundation for the diagnosis of acute myocardial infarction (AMI). Although current cardiac-specific assays are effective, they are often limited by decreased sensitivity and impression.
The Universal Definition of Myocardial Infarction (UDMI) recommends as an “optimal precision” the coefficient of variation (CV) at the 99th percentile upper reference limit to be less than 10%. The Roche Generation 5 Cardiac Troponin T meets the UDMI criteria for “guideline acceptable” precision and the International Federation of Clinical Chemistry (IFCC) definition of a high sensitivity assay.
Important points
- Units of Measure: Results are currently reported in ug/L. The new troponin 5th generation will be reported in ng/L.
- Sex-Specific Reference Ranges: < 14 ng/L for females, < 22 ng/L for males, and < 19 ng/L for not specified.
- Critical Value Has Changed: The new critical value for the 5th generation troponin assay will be >14 ng/L for Females, > 22 ng/L for Males, and > 19 ng/L for not specified.
- Only Li-Heparin Plasma Specimens: Test is not FDA approved on serum. Serum specimens will be rejected.
| Name | Order Code |
| Troponin T | 4017 |
Changes in reporting
| Assay | Order Code | Previous Clinical Reporting Range | New Clinical Reporting Range |
| Troponin T | 4017 | 0.010 - 250 ug/L | 6-10,000 ng/L |
| Assay | Order Code | Previous Reference Range | New Reference Range |
| Troponin T | 4017 | < 0.010 ug/L |
< 14 ng/L for females < 22 ng/L for males < 19 ng/L for not specified |
| Assay | Order Code | Previous Critical Range | New Critical Range |
| Troponin T | 4017 | > 0.010 ug/L |
14 ng/L for females < 22 ng/L for males < 19 ng/L for not specified |
| Order-Unit Codes and Test Names | 4017 Troponin T |
| Specimen Requirements | 1 ML LI-HEPARIN PLASMA. LI-HEPARIN PLASMA TUBES CONTAINING SEPARATING GEL CAN BE USED. CENTRIFUGE SAMPLE WITHIN 2 HRS OF COLLECTION. TRANSFER PLASMA TO A PLASTIC TRANSPORT TUBE. CLEARLY LABEL AS HEPARIN PLASMA. FREEZE. CRITICAL FROZEN (CFZ). WHEN MULTIPLE TESTS ARE ORDERED, SUBMIT SEPARATE TUBE FOR THIS TEST. NOTE: DO NOT COLLECT SAMPLES FROM PATIENTS RECEIVING THERAPY WITH HIGH BIOTIN DOSES (>5 MG/DAY) UNTIL AT LEAST 8 HOURS FOLLOWING THE LAST BIOTIN ADMINISTRATION. |
| Transport Temperature | Critical Frozen |
| Stability (collection to initiation of testing) |
Ambient, 15-25°C: N/A |
| Performed | Monday through Friday / PM Shift |
| Analytic Time | 1 day |
| CPT Code | 84484 |