Understanding our advice ~ December 2003 The use of troponin testing in acute coronary syndromes
The use of troponin testing in acute coronary syndromes Purpose of this document NHS Quality Improvement Scotland (NHS QIS) has issued Advice to NHSScotland on the use of troponin testing in acute coronary syndromes after considering if it is clinically and cost effective, and how it could best be organised in Scotland. We have advised NHSScotland that troponin testing should be available in all hospitals in Scotland that receive patients with heart-related chest pain. This brochure has been produced to explain our Advice on the use of troponin testing to people who do not have specialist knowledge in this area. It explains what the Advice means for people who have undergone, or may have to undergo, a troponin test, how we formed the Advice, and what values we applied to the evidence about troponin testing. The full evidence is discussed in detail in Health Technology Assessment 4: The organisation of troponin testing services in acute coronary syndromes. The words in bold are explained in the Glossary at the end of this document. 1
What is troponin testing? A troponin test is a simple blood test that can help establish if someone with chest pain has had a heart attack (also known as an acute myocardial infarction), or has a high or low risk of further heart damage. It takes its name from proteins, called troponins, that are released into the blood when muscle cells of the heart are damaged. A blood test will show how much troponin is in the blood and provides a quick and accurate measure of heart muscle damage that can help doctors make a diagnosis and inform the patient about potential further risk. In some hospitals the blood sample will be sent to a laboratory to get the results, in others this can be done on the ward (this is called point-of-care testing). A positive result means that people are at high risk of further damage and can get the right treatment sooner. A negative result means that people are at low risk of further damage and can go home earlier safely. However, troponin tests alone cannot be used to make a diagnosis. The doctor will also consider the results of other tests, including an electrocardiogram (ECG), medical history, and signs and symptoms of the patient. 2
The use of troponin testing in acute coronary syndromes Treatment in Scotland About 20-30% of all emergency medical admissions in the UK involve patients with chest pain, but less than one third of those will be kept in hospital because of an acute coronary syndrome, which includes heart attack and unstable angina. Troponin tests can help doctors decide which patients have, or do not have, these conditions. Over the past few years, many hospitals have begun to use troponin testing, but it has been used in different ways and there have been different views about how well it works and confusion about its best use. So, NHS QIS studied the evidence on troponin testing to advise the health service in Scotland on the most effective way to use it. We found that troponin testing is good value for money and recommended that it should be available in all hospitals seeing patients with chest pains. We have recommended that troponin testing should be used with other information so that a proper diagnosis can be made. A doctor will also need to consider the results of an ECG reading, physical symptoms, and a patient s medical history before diagnosing the cause of the chest pain. If, as a result, a patient appears not to have an acute coronary syndrome or other serious illness, the doctor will organise a stress test for the patient. This stress test will complete the assessment and confirm if the patient is at low risk. Currently in Scotland, patients will have their troponin tests taken at different times, depending on the hospital they go to and their condition. We have recommended that most patients with suspected acute coronary syndromes should have a troponin test 12 hours after their symptoms begin. If a patient is not sure when the symptoms began, the test should be taken no later than 12 hours after they are admitted. This will make sure that troponin is measured within the period when it is at its highest. 3
Some patients will have their troponin tested as soon as they get to hospital. This could be because there is uncertainty about the cause of the chest pain following an ECG and examination by the doctor. Alternatively, it may be because the hospital has point-of-care testing and a specialist cardiology or observation unit. In such cases, if the results come back negative, i.e. the troponin level is too low to be detected or it is not present in the blood, the test will be taken again, no later than 12 hours after admission. Sometimes patients will not have a troponin test until after their treatment has begun. For example, if a patient is having a heart attack when they arrive at hospital, treatment will be given immediately. In this case a troponin test will be taken 12 hours after admission to see how the treatment is working and what damage has been done to the heart. Doctors should explain to patients how their diagnosis was made and what treatment options are available. There are many different words used to explain different types of heart damage and heart conditions. From the time a patient is given a diagnosis in a hospital to subsequently seeing their GP, health professionals should use the same terms for the diagnosis. If patients, or their carers, are unclear about any of the terms or any part of their treatment they are encouraged to ask their doctor to explain. When a patient is being discharged, they should be told what to do if the pain comes back. If carers have any concerns, they should raise these with hospital staff or their GP. Doctors and nurses have been advised to make sure that patients and carers understand the information they have been given and provide patients and carers with written information to take away and read. 4
The use of troponin testing in acute coronary syndromes How we formed our Advice We used an internationally recognised process called Health Technology Assessment to form our Advice. The assessment took account of the social, ethical, medical and economic implications of using troponin testing. It brought together: scientific evidence (e.g. journal articles) + expertise of health professionals + needs and preferences of people with acute coronary syndromes while considering the way NHSScotland is organised and how patients are currently managed. We worked with a group of doctors, cardiologists, biochemists, nurses and patients to look at all the evidence. The evidence was recorded in a consultation report. Comments received during consultation were published on the web and taken account of in our scientific document, the Health Technology Assessment Report, and our Advice to the health service in Scotland. 5
Evidence used We gathered evidence from around the world. We use the word evidence to include information collected from a variety of sources, and we use different types of evidence to answer different types of questions. For example: Patient issues What information needs do patients and carers have? Do they understand their diagnosis and what it means? Evidence came from journal articles and discussion groups with patients. Clinical effectiveness Is troponin testing effective and accurate? When should it be used? Is ward-based testing as accurate as laboratory-based testing? Evidence came from journal articles, studies and manufacturers. Costs and benefits How much does a ward-based troponin test cost compared with a laboratory-based test? What savings can NHSScotland make through the early discharge of low-risk patients? What are the costs and benefits of performing a troponin test at different times after a patient arrives? Evidence came from studies we made on costs, savings and incidence of heart disease, and information about clinical effectiveness. Organisational issues Are staff properly trained to carry out a troponin test? Is the equipment they use quality assured? 6
The use of troponin testing in acute coronary syndromes Evidence came from our national surveys, manufacturers, other bodies that ensure the quality of health equipment, and health professionals in Scotland. The following diagram is an example of how all four types of evidence came together to help form our Advice. Clincal Effectiveness Cost and Benefits Troponin testing is not expensive and low-risk patients can be safely sent home sooner, ensuring beds and treatment can be devoted to those in most clinical need. ; Troponin testing, when used with ECG and other examinations, provides an accurate diagnosis of damage to the heart, allowing patients to get the right treatment sooner. It is effective 12 hours after pain begins. ; Advice Troponin testing should be available in all hospitals in Scotland that receive patients with chest pain. It should be measured on admission, 12 hours after admission, or 12 hours after pain begins, depending on patient and the treatment facilities at the hospital. ; Organisational Issues Troponin testing should be laboratory or ward-based, according to local needs, and should be provided by appropriately trained professionals. ; Patient Issues Some patients delay seeing their doctor about their chest pains. Many patients want as much information as possible when they are diagnosed. All healthcare professionals that treat people with chest pain should use the same terminology when giving this information. 7
Sources of support and information Patients and carers should be given the following information, whatever the outcome of their troponin test: what has happened how their diagnosis was made and what terms mean treatment options what could or will happen next why earlier treatment options are no longer being offered what are the chances of further problems what to do and who to contact if pain returns If you, or someone you care for, has an acute coronary syndrome then you can discuss our Advice with your doctor or nurse. Further information about heart disease is available from the British Heart Foundation (www.bhf.org.uk), tel. 08450 70 80 70. Additional advice is available from Chest, Heart and Stroke Scotland (www.chss.org.uk), tel. (0131) 225 6963. The NHS QIS Advice to NHSScotland, Health Technology Assessment Advice 4: The organisation of troponin testing services in acute coronary syndromes (ACS) and full scientific report, Health Technology Assessment Report 4: The organisation of troponin testing services in acute coronary syndromes (ACS) are available from NHS QIS or its website, www.nhshealthquality.org. 8
The use of troponin testing in acute coronary syndromes Glossary Acute coronary syndromes Advice Conditions associated with possible or actual heart damage caused by impaired blood supply. Evidence-based recommendations made by NHS QIS about any aspect of healthcare including medicines, devices, clinical procedures, and healthcare settings. NHS Boards and health professionals are expected to take account of NHS QIS Advice when making decisions about services Biochemist for patients. A person who specialises in biochemical reactions and their measurements in human cells, tissues and organisms. Cardiologist A doctor who specialises in heart disease. Clinical effectiveness The evaluation of benefit against risk in a standard clinical setting using outcomes of importance to the Electrocardiogram Health technology patient. A recording of the electrical activity of the heart using leads placed on the chest. An intervention used to promote health; prevent, diagnose or treat disease; or provide rehabilitation or long-term care. This includes medicines, devices, Incidence NHSScotland clinical procedures and healthcare settings. The frequency with which a disease appears in a particular population or area. The National Health Service in Scotland. 9
Stress test A test where the patient exercises on a treadmill, while its speed and elevation increase. During the test, the patient s electrocardiogram, heart rate, heart rhythm, and blood pressure are continuously Unstable angina monitored. Severe chest pain that is due to an inadequate supply of oxygen to the heart. 10
The use of troponin testing in acute coronary syndromes NHS Quality Improvement Scotland (NHS QIS) Our role is to improve the quality of healthcare in Scotland. We provide clear, authoritative advice on effective clinical practice, set national standards and monitor and publish reports on performance. We also advise on health interventions that are value for money, commission clinical guidelines and support the implementation of clinical governance. To advise on value for money, we must balance how well a treatment works with how much it costs. Feedback Understanding our Advice aims to explain the work of NHS QIS in a way that everyone can understand. We would warmly welcome feedback on this brochure. For example, have we clearly explained our Advice on troponin testing in acute coronary syndromes, and do you have any questions about our Advice that were not answered here. Please give feedback to Rob MacPhail, Communications Officer, NHS Quality Improvement Scotland, Delta House, 50 West Nile Street, Glasgow G1 2NP, tel. 0141 225 6992, email: rob.macphail@nhshealthquality.org 11
The use of troponin testing in acute coronary syndromes
NHS Quality Improvement Scotland, December 2003 ISBN 1-903961-41-6 First published December 2003 NHS Quality Improvement Scotland consents to the photocopying, electronic reproduction by uploading or downloading from the website, retransmission, or other copying of this document for the purpose of implementation in NHSScotland and educational and not for profit purposes. No reproduction by or for commercial organisations is permitted without the express written permission of NHS Quality Improvement Scotland.
This document can be viewed on the NHS Quality Improvement Scotland website. It is also available, on request, from NHS quality Improvement Scotland in the following formats: Electronic Audio cassette Large print NHS Quality Improvement Scotland Glasgow Office ~ Delta House 50 West Nile Street Glasgow G1 2NP Tel 0141 225 6999 Edinburgh Office ~ Elliott House 8-10 Hillside Crescent Edinburgh EH7 5EA Tel 0131 623 4300 comments@nhshealthquality.org www.nhshealthquality.org This document is produced from elemental chlorine-free material and is sourced from sustainable forests