Recent-onset chest pain of suspected cardiac origin: assessment and diagnosis

Check immediately whether people currently have chest pain. If they are pain free, check when their last episode of pain was, particularly if they have had pain in the last 12 hours. [2010]

Determine whether the chest pain may be cardiac and therefore whether this guideline is relevant, by considering:

• the history of the chest pain

• the presence of cardiovascular risk factors

• history of ischaemic heart disease and any previous treatment

• previous investigations for chest pain. [2010]

Initially assess people for any of the following symptoms, which may indicate an ACS:

• pain in the chest and/or other areas (for example, the arms, back or jaw) lasting longer than 15 minutes

• chest pain associated with nausea and vomiting, marked sweating, breathlessness, or particularly a combination of these

• chest pain associated with haemodynamic instability

• new onset chest pain, or abrupt deterioration in previously stable angina, with recurrent chest pain occurring frequently and with little or no exertion, and with episodes often lasting longer than 15 minutes. [2010]

Do not use people's response to glyceryl trinitrate (GTN) to make a diagnosis. [2010]

Do not assess symptoms of an ACS differently in men and women. Not all people with an ACS present with central chest pain as the predominant feature. [2010]

Do not assess symptoms of an ACS differently in ethnic groups. There are no major differences in symptoms of an ACS among different ethnic groups. [2010]

Refer people to hospital as an emergency if an ACS is suspected (see recommendation 1.2.1.3) and:

• they currently have chest pain or

• they are currently pain free, but had chest pain in the last 12 hours, and a resting 12‑lead ECG is abnormal or not available. [2010]

If an ACS is suspected (see recommendation 1.2.1.3) and there are no reasons for emergency referral, refer people for urgent same-day assessment if:

• they had chest pain in the last 12 hours, but are now pain free with a normal resting 12‑lead ECG or

• the last episode of pain was 12 to 72 hours ago. [2010]

Refer people for assessment in hospital if an ACS is suspected (see recommendation 1.2.1.3) and:

• the pain has resolved and

• there are signs of complications such as pulmonary oedema.
  
  Use clinical judgement to decide whether referral should be as an emergency or urgent same-day assessment. [2010]

If a recent ACS is suspected in people whose last episode of chest pain was more than 72 hours ago and who have no complications such as pulmonary oedema:

• carry out a detailed clinical assessment (see recommendations 1.2.4.2 and 1.2.4.3)

• confirm the diagnosis by resting 12‑lead ECG and blood troponin level

• take into account the length of time since the suspected ACS when interpreting the troponin level.
  
  Use clinical judgement to decide whether referral is necessary and how urgent this should be. [2010]

Refer people to hospital as an emergency if they have a recent (confirmed or suspected) ACS and develop further chest pain. [2010]

When an ACS is suspected, start management immediately in the order appropriate to the circumstances (see the section on immediate management of a suspected acute coronary syndrome) and take a resting 12‑lead ECG (see the section on resting 12-lead ECG). Take the ECG as soon as possible, but do not delay transfer to hospital. [2010]

If an ACS is not suspected, consider other causes of the chest pain, some of which may be life-threatening (see recommendations 1.2.6.5, 1.2.6.7 and 1.2.6.8). [2010]

Take a resting 12‑lead ECG as soon as possible. When people are referred, send the results to hospital before they arrive if possible. Recording and sending the ECG should not delay transfer to hospital. [2010]

Follow local protocols for people with a resting 12‑lead ECG showing regional ST‑segment elevation or presumed new left bundle branch block (LBBB) consistent with an acute STEMI until a firm diagnosis is made. Continue to monitor (see recommendation 1.2.3.4). [2010]

Follow the NICE guideline on acute coronary syndromes for people with a resting 12‑lead ECG showing regional ST‑segment depression or deep T wave inversion suggestive of a NSTEMI or unstable angina until a firm diagnosis is made. Continue to monitor (see recommendation 1.2.3.4). [2010]

Even in the absence of ST‑segment changes, have an increased suspicion of an ACS if there are other changes in the resting 12‑lead ECG, specifically Q waves and T wave changes. Consider following the NICE guideline on acute coronary syndromes if these conditions are likely. Continue to monitor (see recommendation 1.2.3.4). [2010]

Do not exclude an ACS when people have a normal resting 12‑lead ECG. [2010]

If a diagnosis of ACS is in doubt, consider:

• taking serial resting 12‑lead ECGs

• reviewing previous resting 12‑lead ECGs

• recording additional ECG leads.
  
  Use clinical judgement to decide how often this should be done. Note that the results may not be conclusive. [2010]

Obtain a review of resting 12‑lead ECGs by a healthcare professional qualified to interpret them as well as taking into account automated interpretation. [2010]

If clinical assessment (as described in recommendation 1.2.1.10) and a resting 12‑lead ECG make a diagnosis of ACS less likely, consider other acute conditions. First consider those that are life-threatening such as pulmonary embolism, aortic dissection or pneumonia. Continue to monitor (see recommendation 1.2.3.4). [2010]

Offer pain relief as soon as possible. This may be achieved with GTN (sublingual or buccal), but offer intravenous opioids such as morphine, particularly if an acute myocardial infarction (MI) is suspected. [2010]

Offer people a single loading dose of 300 mg aspirin as soon as possible unless there is clear evidence that they are allergic to it.

If aspirin is given before arrival at hospital, send a written record that it has been given with the person.

Only offer other antiplatelet agents in hospital. Follow the NICE guideline on acute coronary syndromes. [2010]

Do not routinely administer oxygen, but monitor oxygen saturation using pulse oximetry as soon as possible, ideally before hospital admission. Only offer supplemental oxygen to:

• people with oxygen saturation (SpO₂) of less than 94% who are not at risk of hypercapnic respiratory failure, aiming for SpO₂ of 94% to 98%

• people with chronic obstructive pulmonary disease who are at risk of hypercapnic respiratory failure, to achieve a target SpO₂ of 88% to 92% until blood gas analysis is available. [2010]
  
  Be aware that some pulse oximeters can underestimate or overestimate oxygen saturation levels, especially if the saturation level is borderline. Overestimation has been reported in people with dark skin. See also the NHS England Patient Safety Alert on the risk of harm from inappropriate placement of pulse oximeter probes.

Monitor people with acute chest pain, using clinical judgement to decide how often this should be done, until a firm diagnosis is made. This should include:

• exacerbations of pain and/or other symptoms

• pulse and blood pressure

• heart rhythm

• oxygen saturation by pulse oximetry

• repeated resting 12‑lead ECGs and

• checking pain relief is effective. [2010]

Manage other therapeutic interventions using the NICE guideline on acute coronary syndromes. [2010]

Take a resting 12‑lead ECG and a blood sample for high-sensitivity troponin I or T measurement (see the section on use of biochemical markers for diagnosis of an acute coronary syndrome) on arrival in hospital. [2010, amended 2016]

Carry out a physical examination to determine:

• haemodynamic status

• signs of complications, for example, pulmonary oedema, cardiogenic shock and

• signs of non-coronary causes of acute chest pain, such as aortic dissection. [2010]

Take a detailed clinical history unless a STEMI is confirmed from the resting 12‑lead ECG (that is, regional ST‑segment elevation or presumed new LBBB). Record:

• the characteristics of the pain

• other associated symptoms

• any history of cardiovascular disease

• any cardiovascular risk factors and

• details of previous investigations or treatments for similar symptoms of chest pain. [2010]

Do not use high-sensitivity troponin tests for people in whom ACS is not suspected. [2016]

For people at high or moderate risk of MI (as indicated by a validated tool), perform high-sensitivity troponin tests as recommended in the NICE diagnostics guidance on myocardial infarction. [2016]

For people at low risk of MI (as indicated by a validated tool):

• perform a second high-sensitivity troponin test as recommended in the NICE diagnostics guidance on myocardial infarction if the first troponin test at presentation is positive.

• consider performing a single high-sensitivity troponin test only at presentation to rule out NSTEMI if the first troponin test is below the lower limit of detection (negative). [2016]

Ensure that patients understand that a detectable troponin on the first high-sensitivity test does not necessarily indicate that they have had an MI. [2016]

Do not use biochemical markers such as natriuretic peptides and high-sensitivity C-reactive protein to diagnose an ACS. [2010]

Do not use biochemical markers of myocardial ischaemia (such as ischaemia-modified albumin) as opposed to markers of necrosis when assessing people with acute chest pain. [2010]

When interpreting high-sensitivity troponin measurements, take into account:

• the clinical presentation

• the time from onset of symptoms

• the resting 12‑lead ECG findings

• the pre-test probability of NSTEMI

• the length of time since the suspected ACS

• the probability of chronically elevated troponin levels in some people

• that 99th percentile thresholds for troponin I and T may differ between sexes. [2010, amended 2016]

When diagnosing MI, use the universal definition of myocardial infarction. This is the detection of rise and/or fall of cardiac biomarkers values [preferably cardiac troponin (cTn)] with at least one value above the 99th percentile of the upper reference limit and at least one of the following:

• symptoms of ischaemia

• new or presumed new significant ST‑segment‑T wave (ST‑T) changes or new LBBB

• development of pathological Q waves in the ECG

• imaging evidence of new loss of viable myocardium or new regional wall motion abnormality

• identification of an intracoronary thrombus by angiography. [2010, amended 2016]

When a raised troponin level is detected in people with a suspected ACS, reassess to exclude other causes for raised troponin (for example, myocarditis, aortic dissection or pulmonary embolism) before confirming the diagnosis of ACS. [2010]

When a raised troponin level is detected in people with a suspected ACS, follow the NICE guideline on acute coronary syndromes until a firm diagnosis is made. Continue to monitor (see recommendation 1.2.3.4). [2010]

When a diagnosis of ACS is confirmed, follow the NICE guideline on acute coronary syndromes. [2010]

Reassess people with chest pain without raised troponin levels and no acute resting 12‑lead ECG changes to determine whether their chest pain is likely to be cardiac.

If myocardial ischaemia is suspected, follow the recommendations on stable chest pain in this guideline (see the section on people presenting with stable chest pain). Use clinical judgement to decide on the timing of any further diagnostic investigations. [2010, amended 2016]

Do not routinely offer non-invasive imaging or exercise ECG in the initial assessment of acute cardiac chest pain. [new 2016]

Only consider early chest computed tomography (CT) to rule out other diagnoses such as pulmonary embolism or aortic dissection, not to diagnose ACS. [2010]

Consider a chest X‑ray to help exclude complications of ACS such as pulmonary oedema, or other diagnoses such as pneumothorax or pneumonia. [2010]

If an ACS has been excluded at any point in the care pathway, but people have risk factors for cardiovascular disease, follow the appropriate guidance, for example, the NICE guideline on cardiovascular disease and the NICE guideline on hypertension in adults. [2010]

Take a detailed clinical history documenting:

• the age and sex of the person

• the characteristics of the pain, including its location, radiation, severity, duration and frequency, and factors that provoke and relieve the pain

• any associated symptoms, such as breathlessness

• any history of angina, MI, coronary revascularisation or other cardiovascular disease and

• any cardiovascular risk factors. [2010]

Carry out a physical examination to:

• identify risk factors for cardiovascular disease

• identify signs of other cardiovascular disease

• identify non-coronary causes of angina (for example, severe aortic stenosis, cardiomyopathy) and

• exclude other causes of chest pain. [2010]

Assess the typicality of chest pain as follows:

• Presence of three of the features below is defined as typical angina.

• Presence of two of the three features below is defined as atypical angina.

• Presence of one or none of the features below is defined as non-anginal chest pain.
  
  Anginal pain is:

• constricting discomfort in the front of the chest, or in the neck, shoulders, jaw or arms

• precipitated by physical exertion

• relieved by rest or GTN within about 5 minutes. [2010, amended 2016]

Do not define typical and atypical features of anginal chest pain and non-anginal chest pain differently in men and women. [2010]

Do not define typical and atypical features of anginal chest pain and non-anginal chest pain differently in ethnic groups. [2010]

Take the following factors, which make a diagnosis of stable angina more likely, into account when estimating people's likelihood of angina:

• age

• whether the person is male

• cardiovascular risk factors including:

  • a history of smoking

  • diabetes

  • hypertension

  • dyslipidaemia

  • family history of premature coronary artery disease (CAD)

• other cardiovascular disease

• history of established CAD, for example, previous MI, coronary revascularisation. [2010]

Unless clinical suspicion is raised based on other aspects of the history and risk factors, exclude a diagnosis of stable angina if the pain is non-anginal (see recommendation 1.3.3.1). Features which make a diagnosis of stable angina unlikely are when the chest pain is:

• continuous or very prolonged and/or

• unrelated to activity and/or

• brought on by breathing in and/or

• associated with symptoms such as dizziness, palpitations, tingling or difficulty swallowing.
  
  Consider causes of chest pain other than angina (such as gastrointestinal or musculoskeletal pain). [2010]

Consider investigating other causes of angina, such as hypertrophic cardiomyopathy, in people with typical angina-like chest pain and a low likelihood of CAD. [2010, amended 2016]

Arrange blood tests to identify conditions which exacerbate angina, such as anaemia, for all people being investigated for stable angina. [2010]

Only consider chest X‑ray if other diagnoses, such as a lung tumour, are suspected. [2010]

If a diagnosis of stable angina has been excluded at any point in the care pathway, but people have risk factors for cardiovascular disease, follow the appropriate guidance, for example, the NICE guideline on cardiovascular disease and the NICE guideline on hypertension in adults. [2010]

For people in whom stable angina cannot be excluded on the basis of the clinical assessment alone, take a resting 12‑lead ECG as soon as possible after presentation. [2010, amended 2016]

Do not rule out a diagnosis of stable angina on the basis of a normal resting 12‑lead ECG. [2010]

Do not offer diagnostic testing to people with non-anginal chest pain on clinical assessment (see recommendation 1.3.3.1) unless there are resting ECG ST‑T changes or Q waves. [2016]

A number of changes on a resting 12‑lead ECG are consistent with CAD and may indicate ischaemia or previous infarction. These include:

• pathological Q waves in particular

• LBBB

• ST‑segment and T wave abnormalities (for example, flattening or inversion).
  
  Note that the results may not be conclusive.
  
  Consider any resting 12‑lead ECG changes together with people's clinical history and risk factors. [2010]

For people with confirmed CAD (for example, previous MI, revascularisation, previous angiography) in whom stable angina cannot be excluded based on clinical assessment alone, see recommendation 1.3.4.4 about functional testing. [2010, amended 2016]

Consider aspirin only if the person's chest pain is likely to be stable angina, until a diagnosis is made. Do not offer additional aspirin if there is clear evidence that people are already taking aspirin regularly or are allergic to it. [2010]

Follow the NICE guideline on stable angina while waiting for the results of investigations if symptoms are typical of stable angina. [2010]

Include the typicality of anginal pain features (see recommendation 1.3.3.1) in all requests for diagnostic investigations and in the person's notes. [2010, amended 2016]

Use clinical judgement and take into account people's preferences and comorbidities when considering diagnostic testing. [2010]

Offer 64‑slice (or above) CT coronary angiography if:

• clinical assessment (see recommendation 1.3.3.1) indicates typical or atypical angina or

• clinical assessment indicates non-anginal chest pain but 12‑lead resting ECG has been done and indicates ST‑T changes or Q waves. [2016]

For people with confirmed CAD (for example, previous MI, revascularisation, previous angiography), offer non-invasive functional testing when there is uncertainty about whether chest pain is caused by myocardial ischaemia. See the section on use of non-invasive functional testing for myocardial ischaemia for further guidance on non-invasive functional testing. An exercise ECG may be used instead of functional imaging. [2010]

See also NICE's medical technologies guidance on HeartFlow FFRCT for estimating fractional flow reserve from coronary CT angiography. Using HeartFlow FFR_CT may avoid the need for invasive coronary angiography and revascularisation for some patients

Offer non-invasive functional imaging (see the section on use of non-invasive functional testing for myocardial ischaemia) for myocardial ischaemia if 64‑slice (or above) CT coronary angiography has shown CAD of uncertain functional significance or is non-diagnostic. [2016]

Offer invasive coronary angiography as a third-line investigation when the results of non-invasive functional imaging are inconclusive. [2016]

When offering non-invasive functional imaging for myocardial ischaemia use:

• myocardial perfusion scintigraphy with single photon emission computed tomography (MPS with SPECT) or

• stress echocardiography or

• first-pass contrast-enhanced magnetic resonance (MR) perfusion or

• MR imaging for stress-induced wall motion abnormalities.
  
  Take account of locally available technology and expertise, the person and their preferences, and any contraindications (for example, disabilities, frailty, limited ability to exercise) when deciding on the imaging method. [This recommendation updates and replaces recommendation 1.1 of NICE's technology appraisal guidance on myocardial perfusion scintigraphy for the diagnosis and management of angina and myocardial infarction]. [2016]

Use adenosine, dipyridamole or dobutamine as stress agents for MPS with SPECT and adenosine or dipyridamole for first-pass contrast-enhanced MR perfusion. [2010]

Use exercise or dobutamine for stress echocardiography or MR imaging for stress-induced wall motion abnormalities. [2010]

Do not use MR coronary angiography for diagnosing stable angina. [2010]

Do not use exercise ECG to diagnose or exclude stable angina for people without known CAD. [2010]

Confirm a diagnosis of stable angina and follow the NICE guideline on stable angina when:

• significant CAD (see box 1) is found during invasive or 64‑slice (or above) CT coronary angiography or

• reversible myocardial ischaemia is found during non-invasive functional imaging. [2016]

Investigate other causes of chest pain when:

• significant CAD (see box 1) is not found during invasive coronary angiography or 64‑slice (or above) CT coronary angiography or

• reversible myocardial ischaemia is not found during non-invasive functional imaging. [2016]

Consider investigating other causes of angina, such as hypertrophic cardiomyopathy or syndrome X, in people with typical angina-like chest pain if investigation excludes flow-limiting disease in the epicardial coronary arteries. [2010]