Guidance
2 The diagnostic tests
Clinical need and practice
2.1 Chest pain and suspected myocardial infarction were the cause of about 5% of all emergency hospital admissions in 2017 to 2018. However, myocardial infarction will have occurred in only about 20% of those admissions. Tests that can quickly tell whether a person is having a myocardial infarction or not could mean that unnecessary hospital admissions are avoided, reducing waiting time and anxiety for many people.
2.2 Cardiac troponins I and T are biological markers of cardiac muscle death (cardiomyocyte necrosis). They are released into the circulation, so rise when the cardiac muscle is damaged. They are used as markers of acute myocardial infarction along with clinical history taking and electrocardiography (ECG) monitoring. ST-segment elevation myocardial infarction (STEMI) can usually be diagnosed by ECG alone. So, the main diagnostic challenge is detecting or ruling out non-ST-segment elevation myocardial infarction (NSTEMI).
2.3 The optimum sensitivity of older (non-high-sensitivity) troponin tests (referred to here as standard troponin tests) for acute myocardial infarction is 10 to 12 hours after the onset of symptoms. For many people, this means hospital admission and observation while serial troponin testing is done. To overcome this, high-sensitivity troponin tests have been developed. These can detect lower levels of troponin in the blood earlier than standard troponin tests, so enable early rule out of NSTEMI after the onset of acute chest pain. This could lead to fewer people being admitted to hospital, earlier discharge for people with normal troponin levels and earlier intervention for those with a confirmed NSTEMI.
2.4 NICE's 2014 guidance on high-sensitivity troponin tests recommended the Elecsys troponin T-high sensitive test and ARCHITECT STAT High Sensitive Troponin‑I test as options for the early rule out of NSTEMI in people presenting to an emergency department with chest pain and suspected acute coronary syndrome. Since that guidance was published, NICE's guideline on recent-onset chest pain of suspected cardiac origin has been updated to include high-sensitivity troponin tests. But stakeholder feedback suggests that high-sensitivity troponin testing used with early rule-out strategies has not been routinely adopted in the NHS and, if it has, there is wide variation in how it is being done. This updated assessment is being done to ensure that guidance is based on evidence including new high-sensitivity tests developed and marketed since publication of the NICE guidance. It is also to provide more detailed recommendations on how to use high-sensitivity tests (for example, timing of testing and using sequential testing strategies) when possible.
The interventions
2.5 All tests included in the assessment are CE marked and available to the NHS.
Access High-Sensitivity Troponin I Assay (Beckman Coulter)
2.6 The Access test is designed to be used in a laboratory with the Beckman Coulter Access 2 and DxI/DxC analysers. The company says that the test's performance is the same regardless of analyser. It is a paramagnetic particle chemiluminescent immunoassay for in-vitro quantitative determination of troponin I in serum and plasma samples. Results are available in 17 minutes. Recommended 99th percentile cut-offs are:
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17.5 ng/litre for the whole population
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11.6 ng/litre for women
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19.8 ng/litre for men.
Each 99th percentile has a coefficient of variation (CV) of less than 10%. The test can detect troponin I in more than 97% of the reference population.
ARCHITECT STAT High Sensitive Troponin‑I assay (Abbott Diagnostics)
2.7 The ARCHITECT test is designed to be used in a laboratory with the Abbott ARCHITECT i2000SR and i1000SR analysers. The test is a chemiluminescent microparticle immunoassay for in-vitro quantitative determination of troponin I in serum and plasma samples. Results are available in 18 minutes. The ARCHITECT test can detect troponin I in 96% of the reference population. Recommended 99th percentile cut-offs are:
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26.2 ng/litre for the whole population with a CV of 4%
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15.6 ng/litre for women (CV 5.3%)
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34.2 ng/litre for men (CV 3.5%).
Alinity High Sensitive Troponin‑I assay (Abbott Diagnostics)
2.8 The Alinity test is designed to be used in a laboratory with the Alinity i analyser. It is a chemiluminescent microparticle immunoassay for the quantitative determination of troponin I in plasma and serum samples. Results are available in 18 minutes. Recommended 99th percentile cut-offs are:
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26.2 ng/litre for the whole population with a CV of 4.6%
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15.6 ng/litre for women (CV 5.0%)
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34.2 ng/litre for men (CV 4.5%).
ADVIA Centaur High-Sensitivity Cardiac Troponin I Assay (Siemens Healthineers)
2.9 The ADVIA Centaur test is designed to be used in a laboratory with the Siemens ADVIA Centaur XP and ADVIA Centaur XPT analysers. It is a magnetic latex particle chemiluminescent immunoassay for the in-vitro quantitative determination of troponin I in serum and plasma samples. Test results are available in 18 minutes. Recommended 99th percentile cut-offs are:
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47.34 ng/litre in lithium heparin and 46.47 ng/litre in serum for the whole population
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36.99 ng/litre in lithium heparin and 39.59 ng/litre in serum for women
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57.27 ng/litre in lithium heparin and 58.05 ng/litre in serum for men.
Each 99th percentile has a CV of less than 10%. The test can detect troponin I in more than 50% of the reference population.
Atellica IM High-Sensitivity Cardiac Troponin I Assay (Siemens Healthineers)
2.10 The Atellica test is designed to be used in a laboratory with the Siemens Atellica IM analyser. It is a magnetic latex particle chemiluminescent immunoassay for the in-vitro quantitative determination of troponin I in serum and plasma samples. Test results are available in 10 minutes. Recommended 99th percentile cut-offs are:
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45.2 ng/litre in lithium heparin and 45.43 ng/litre in serum for the whole population
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34.11 ng/litre in lithium heparin and 38.64 ng/litre in serum for women
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53.48 ng/litre in lithium heparin and 53.53 ng/litre in serum for men.
Each 99th percentile has a CV of less than 10%. The test can detect troponin I in more than 50% of the reference population.
Dimension EXL High-Sensitivity Cardiac Troponin I Assay (Siemens Healthineers)
2.11 The Dimension EXL test is designed to be used in a laboratory with the Siemens Dimension EXL analyser. It is a magnetic latex particle chemiluminescent immunoassay for the in-vitro quantitative determination of troponin I in serum and plasma samples. Test results are available in 18 minutes. Recommended 99th percentile cut-offs are:
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60.4 ng/litre in lithium heparin and 58.2 ng/litre in serum for the whole population
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51.4 ng/litre in lithium heparin and 47.8 ng/litre in serum for women
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76.2 ng/litre in lithium heparin and 71.8 ng/litre in serum for men.
Each 99th percentile has a CV of less than 10%. The test can detect troponin I in more than 50% of the reference population.
Dimension Vista High-Sensitivity Cardiac Troponin I Assay (Siemens Healthineers)
2.12 The Dimension Vista test is designed to be used in a laboratory with the Siemens Dimension Vista analysers. It is a magnetic latex particle chemiluminescent immunoassay, and is intended for the in-vitro quantitative determination of troponin I in serum and plasma samples. Test results are available in 10 minutes. Recommended 99th percentile cut-offs are:
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58.9 ng/litre in lithium heparin and 57.9 ng/litre in serum for the whole population
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53.77 ng/litre in lithium heparin and 51.1 ng/litre in serum for women
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78.5 ng/litre in lithium heparin and 74.9 ng/litre in serum for men.
Each 99th percentile has a CV of less than 10%. The test can detect troponin I in more than 50% of the reference population.
Elecsys troponin T-high sensitive assay (Roche)
2.13 The Elecsys and Elecsys STAT tests are designed to be used in a laboratory on the Roche cobas e411, e601, and e602 analysers. The company says that performance is the same when used on these analysers. The test can also be run on the cobas e801 analyser, which is designed for very high throughput as both a standard and STAT test. The Elecsys test is a sandwich electrochemiluminescence immunoassay for in-vitro quantitative determination of troponin T in serum and plasma samples. Results are available in 18 minutes with the standard test and in 9 minutes with the STAT test. Both tests can detect troponin T in 57% of the reference population. Recommended 99th percentile cut-offs are:
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14.0 ng/litre for the whole population with a CV of less than 10%
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9.0 ng/litre for women
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16.8 ng/litre for men.
TriageTrue High Sensitivity Troponin I Test (Quidel Cardiovascular)
2.14 The TriageTrue test can be used at point of care or in a laboratory with the Triage MeterPro analyser. It is a fluorescence immunoassay for the in‑vitro quantitative determination of troponin I in EDTA anticoagulated whole blood and plasma samples. Test results are available in less than 20 minutes. Recommended 99th percentile cut-offs are:
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20.5 ng/litre for the whole population with a CV of less than 10%
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14.4 ng/litre for women
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25.7 ng/litre for men.
The test can detect troponin I in more than 50% of the reference population.
VITROS High Sensitivity Troponin I Assay (Ortho Clinical Diagnostics)
2.15 The VITROS test is designed to be used in a laboratory on the following analysers: VITROS ECi/ECiQ/3600 Immunodiagnostic Systems and the VITROS 5600/XT 7600 Integrated System. It is an immunometric immunoassay for the in-vitro quantitative determination of troponin I in serum and plasma samples. Test results are available in 15 minutes. Recommended 99th percentile cut-offs are:
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11 ng/litre in lithium heparin and serum for the whole population
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9 ng/litre in lithium heparin and serum for women
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13 ng/litre in lithium heparin and 12 ng/litre in serum for men.
The test can detect troponin I in more than 50% of the reference population.
VIDAS High sensitive Troponin I assay (bioMérieux)
2.16 The VIDAS test is designed to be used in a laboratory on the following analysers: VIDAS, MINI VIDAS and VIDAS 3. It is for the in-vitro quantitative determination of troponin I in serum and plasma (lithium heparin) samples. Test results are available in 20 minutes. Recommended 99th percentile cut-offs are:
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19 ng/litre for the whole population
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11 ng/litre for women
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25 ng/litre for men.