Cardiac Troponinfor Earlier Diagnosis of Myocardial Infarctions

Time is Muscle – Earlier MI Diagnosis with High-Sensitivity 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

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.

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.

Siemens Healthineers offers a proven, true high-sensitivity cardiac troponin I assays with fast, accurate, and actionable test results:

  • Demonstrates clinical proof that the Siemens Healthineers' are true high-sensitivity troponin I assays according to the IFCC guidelines.1
  • Offers fast, accurate, and actionable results to leverage faster protocols
  • Provides confidence in results due to minimal assay interferences

High-sensitivity Troponin I is now available on the Atellica® IM Analyzer, ADVIA Centaur® Immunoassay Systems, Dimension® EXL™ and Dimension Vista® Integrated Systems.

Compared to traditional troponin assays, the Siemens Healthineers Atellica IM, ADVIA Centaur, Dimension EXL and Dimension Vista high-sensitivity troponin I 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 below the 99th percentile by delivering precision that provides the ability to measure slight, yet critical, changes between serial troponin I values.

Precision between the limit of quantification and the 99th percentile 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.


Sample Type

Serum, lithium heparin plasma

Sample Volume

100 µL

Assay Range

2.50 - 25,000.00 pg/mL (ng/L)

Time to First Result

10 minutes

On-board Stability

31 days

Calibration Interval

47 days

LoB

0.50 pg/mL (ng/L)

LoD

1.6 pg/mL (ng/L)

LoQ (20% CV)

2.51 pg/mL (ng/L)

LoQ (10% CV)

6 pg/mL (ng/L)
99th Percentile

45.2 pg/mL (ng/L)

Male: 53.5; Female 34.1

Sample Type

Human serum, plasma (lithium heparin)

Sample Volume

100 µL

Assay Range

2.50 – 25,000.00 pg/mL (ng/L)

Time to First Result

XP/XPT: 18 minutes CP: 15 minutes

Throughput

Up to 240 tests/hour

On-board Stability

28 days

Calibration Interval

14 days

LoB

0.50 pg/mL (ng/L)

LoD

1.60 pg/mL (ng/L)

LoQ (20% CV)

2.50 pg/mL (ng/L)

LoQ (10% CV)

6.0 pg/mL (ng/L)

99th Percentile

47.34 ng/L (ng/L) 

Male 57.3; Female 37

Sample Type

Human serum, plasma (lithium heparin)

Sample Volume

10 µL

Assay Range

4.0 - 25,000.00 pg/mL (ng/L)

Time to First Result

10 minutes

Throughput

Up to 200 tests/hour

On-board Stability

7 days open well
30 days onboard unpunctured

LoB

1.1 pg/mL (ng/L)

LoD

2.7 pg/mL (ng/L)

LoQ (20% CV)

4.0 pg/mL (ng/L)

LoQ (10% CV)

12.0 pg/mL (ng/L)

99th percentile (n = 2010)

Combined: 60.4 pg/mL (ng/L)
Male: 76.2 pg/mL (ng/L)
Female: 51.4 pg/mL (ng/L)

Sample Type

Human serum, plasma (lithium heparin)

Sample Volume

10 µL

Assay Range

3.0 - 25,000.00 pg/mL (ng/L)

Time to First Result

10 minutes

Throughput

Up to 200 tests/hour

On-board Stability

7 days open well
30 days onboard unpunctured

LoB

1.0 pg/mL (ng/L)

LoD

2.0 pg/mL (ng/L)

LoQ (20% CV)

3.0 pg/mL (ng/L)

LoQ (10% CV)

10.0 pg/mL (ng/L)

99th percentile (n = 2010)

Combined: 58.9 pg/mL (ng/L)
Male: 78.5 pg/mL (ng/L)
Female: 53.7 pg/mL (ng/L)


Contemporary Sensitive Troponin I Assays

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. 


Dimension EXL Systems
Dimension Vista Systems

Sample Type

Serum, Plasma (Na or Li Heparin)

Serum, Plasma (Na or Li Heparin)

Sample Volume

20 μL
20 μL

Assay Range

17 – 40,000 ng/L
15 - 40,000 ng/L

Time to First Result

10 minutes

10 minutes

On-board Stability

Sealed on-board (at 2-8° C): 30 days
Open well stability: 3 days
Sealed on-board (at 2-8° C): 30 days
Open well stability: 7 days

Calibration Interval

21 days
30 days

Diluent

Manual dilution – 1:5
1:5

Limit of Detection

17 ng/L
15 ng/L

10% CV (Limit of Quantitation)

50 ng/L
40 ng/L

99th Percentile

56 ng/L
45 ng/L

Clinical Guidelines

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

Fourth Universal Definition of Myocardial Infarction Guidelines

Download white paper:

High-Sensitivity Troponin Testing in Accordance with the 2018 Fourth Universal Definition of Myocardial Infarction

AHA/ACC Guidelines - Cardiac Troponin Highlights

  • 99th percentile for cardiac troponin is appropriate cutoff for considering myocardial necrosis
  • For contemporary sensitive 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

2014 AHA/ACC Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes

2015 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 high-sensitivity assay or imaging
  • Rising or falling kinetics helps discriminate acute from chronic illness

European Heart Journal (2016) 37, 267-315

https://academic.oup.com/eurheartj/article/37/3/267/2466099

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)