Time is Muscle – Earlier MI Diagnosis with Sensitive Troponin Assays
The detection of a rise and/or fall of cardiac troponin (cTn) plays a key role in the earlier diagnosis of myocardial infarction (MI). Cardiac troponins are markers of myocardial necrosis, and, because of their high cardiac-specificity, are the preferred biomarker for the diagnosis of MI.
Reliable Answers for Critical Needs
As a recognized worldwide leader in CVD testing, Siemens Healthineers High-Sensitivity Troponin I assays provide the clinical sensitivity and precision needed for earlier detection of necrosis and MI versus less-precise assays.
Preferred Biomarker of Cardiac Injury
Troponin is a complex of three contractile regulatory proteins, troponin C, T and I, that control the calcium mediated interactions between actin and myosin in cardiac and skeletal muscles.
- Troponin I and T are specific to cardiac muscles, unlike troponin C which is associated with both cardiac and skeletal muscles.
- Troponin C is not used in the diagnosis of myocardial damage.
- Both Troponin I and Troponin T are released into circulation at the time of injury following the same release pattern in the system. However, cardiac Troponin I is slightly more differentiated from skeletal Troponin I than cardiac Troponin T is from skeletal Troponin T.
Cardiac troponins are released into circulation in response to myocardial necrosis. As such, cardiac troponins are the preferred biomarkers for the detection of cardiac injury, and have long assisted physicians in improving diagnostic strategies for the effective management of patients with chest pain.
- Relatively non-specific markers of myocardial damage, such as creatine kinase (CK), creatine kinase-MB (CK-MB), and myoglobin (MYO), were used in diagnostic laboratories prior to the commercial release of the troponin assays.
- Numerous clinical studies on troponin have indicated its superior cardiac specificity in comparison to CK, CK-MB, or MYO.
- Troponin levels remain elevated in the blood longer than CK-MB or MYO, providing an extended diagnostic window for MI.
High-Sensitivity Troponin I
High-Sensitivity Troponin I is the latest addition to Siemens Healthineers’ comprehensive cardiac menu to assist clinicians with the diagnosis and treatment of chest pain patients. Designed to aid in diagnosing acute myocardial infarctions (AMI) through the quantitative measurement of cardiac troponin I in serum or plasma, high-sensitivity troponin plays a critical role in the timely diagnosis of AMI, or heart attacks.
High-sensitivity Troponin I is now available on the Atellica® IM Analyzer, ADVIA Centaur® Immunoassay System, Dimension® EXL™* and Dimension Vista® Integrated Systems.
- Offers improved patient care with a high-sensitivity cardiac troponin assay that meets current guideline recommendations.
- Allows you to measure slight, yet critical, changes between serial troponin I values, giving you confidence in patient results at the low end of the assay range.
- Delivers reliable results from proven, trusted technology coupled with three new monoclonal antibodies.
Compared to traditional troponin assays, the Siemens Healthineers Atellica IM, ADVIA Centaur, Dimension EXL and Dimension Vista TNIH assays are able to detect lower levels of troponin and smaller changes to a patient’s troponin levels, which may be an early indication of AMI. This design affords clinicians greater confidence in patient results at the low end of the assay range by delivering precision that provides the ability to measure slight, yet critical, changes between serial troponin I values.
Precision at the low end is important to minimize analytic variation that could confuse a clinician’s assessment of a clinically significant change. With this data in hand, clinicians have the ability to more quickly diagnose and treat patients with suspected AMI, in some cases in as little as one to three hours.
Atellica IM High-Sensitivity Cardiac Troponin I Assay
ADVIA Centaur High-Sensitivity Cardiac Troponin I Assay
Dimension EXL High-Sensitivity Cardiac Troponin I Assay*
Dimension Vista High-Sensitivity Cardiac Troponin I Assay
Guideline-Acceptable Troponin I
Dimension EXL and Dimension Vista Cardiac Troponin I Assay
The LOCI® Cardiac Troponin I assay on the Dimension® EXL™ and Dimension Vista® systems meets the standard of performance for accurate and rapid results required for timely AMI diagnosis. Employing unique oxygen channeling technology provides greater precision and low background signal with minimal noise improves sensitivity.
- Supports rapid triage of chest pain patients and improves acute care workflow between serial measurements (6h reduced to 3h protocols) with a time to first result in 12 minutes or less.
- Reduces the risk of interference with a low sample volume.
- Improves laboratory workflow with same tube troponin testing with other STAT chemistry assays.
- Delivers confidence in the earlier detection of AMI with demonstrated clinically equivalent to high-sensitive cardiac troponin assays, meeting the guidelines criterion for ≤10%CV at the 99th percentile.
4th Universal Definition of Myocardial Infarction
The 2018 Fourth Universal Definition of MI (ESC/ACC/AHA/WHF Expert Consensus Document) elaborates on the use of hs-cTn assays for differentiating myocardial injury due to ischemic MI and myocardial injury due to nonischemic conditions, both of which can cause elevated cTn concentrations.1
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AHA/ACC Guidelines - Cardiac Troponin Highlights
- 99th percentile for cardiac troponin is appropriate cutoff for considering myocardial necrosis
- For contemporary assays, serial cardiac troponin levels should be measured at presentation and 3 to 6 hours after symptom onset in all patients who present with chest pain symptoms. This identifies a rising and/or falling pattern
- In evaluating serial changes, absolute changes appear to have a significantly higher diagnostic accuracy for AMI than relative changes
ESC Guidelines for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-segment Elevation
- The 99th percentile for cTn is the single decision limit for both AMI and risk in patients presenting with symptoms of cardiac ischemia (either cTnI or cTnT can be used)
- Labs may establish a decision limit for each biomarker based on a normal, healthy population with no evidence of heart disease or use the manufacturer’s established value.
- Imprecision (CV) at the 99th percentile decision point should be ≤ 10%
- Small myocardial injury can be detected using sensitive assay or imaging
- Rising or falling kinetics helps discriminate acute from chronic illness
European Heart Journal (2016) 37, 267-315
IFCC Task Force Recommendations
Supports 99th Percentile
- 99th percentile cut-off universally endorsed
- Determined in a healthy population
- Derived from peer-reviewed literature, or manufacturer
- Analytical precision should be ≤ 10% CV
Defines High-Sensitivity Troponin
- High-sensitivity assays (hs-assays) should measure cTn > limit of detection (LoD) in ≥ 50% of the healthy subjects used to determine the 99th percentile
- Results reported in ng/L or pg/mL instead of µg/L (gives whole number values instead of decimals for easier interpretation)
* Not available for sale in the U.S.
§ Defined by the ESC/ACC committee as an imprecision level of ≤10% at the 99th percentile of normal.
1. Thygesen K, Alpert JS, Jaffe AS, et al. Fourth universal definition of myocardial infarction (2018). J Am Coll Cardiol. 2018.