Cardiac Type Chest Pain Presenting in Primary Care

It is often difficult to be certain as to whether chest pain is of cardiac or non-cardiac cause.¹ Any doubt should lead to referral to secondary care for further assessment, either to the local chest pain clinic or urgent hospital admission.

• 20-40% of all medical admissions are for acute chest pain.²
• CHD remains the principal cause of death in the UK and a fifth of these deaths occur below retirement age.
• The main risk factors are smoking, hypertension, hypercholesterolaemia, diabetes and obesity.

• Patients may present to their GP with a history of angina in the previous few days but are asymptomatic at time of presentation. Angina is likely if chest discomfort or breathlessness are associated with exercise or emotion, symptoms are relieved by rest and/or GTN and one or more risk factors for coronary artery disease are present.³
• It is often difficult to distinguish cardiac from non-cardiac pain.
• Predicting a stable clinical course from symptoms alone is also very difficult but very important as exertional angina can progress to unstable angina, acute myocardial infarction or even death.
• A full history should be taken from the patient to assess the need for either immediate hospital admission or urgent hospital referral.
• Indications for hospital admission: there are no set criteria for admission, but it is important that any patient with either a suspected recent myocardial infarction or unstable angina is admitted to hospital without delay.
• The following should increase the threshold for considering admission to hospital:
  • Symptoms of unstable angina, e.g. angina at rest or nocturnal angina.
  • Pain not immediately relieved by sublingual GTN.
  • Associated symptoms with pain: nausea and/or vomiting, sweating, dizziness, palpitations.
  • Duration of pain longer than hour (even if pain free at time of presentation).
  • Co-morbidity, e.g. diabetes, history of previous myocardial infarction.
• In addition to above, other details should also be obtained:
  • Precipitants of the angina attacks.
  • Smoking history.
  • Amount of exercise taken.
  • Drug history.

• Many patients will have entirely normal examination findings.
• Always check pulse rate and rhythm, blood pressure, auscultate heart sounds (ensure no murmurs, e.g. aortic stenosis can present with angina) and chest (to exclude signs of heart failure).
• Consider findings suggesting non-cardiac chest pain, e.g. tenderness of chest wall.

The main causes of chest pain include:

• Angina, myocardial infarction
• Acute pericarditis
• Oesophageal reflux
• Pneumonia, pulmonary embolus
• Gallstones, cholecystitis
• Acute pancreatitis
• Chest wall pain, e.g. Tietze's syndrome, trauma, shingles
• Aortic dissection
• Anxiety

Patients who present with a clear history suggesting angina, which responds to GTN spray or tablets should be investigated as follows (remembering that many hospitals now have chest pain assessment clinics and investigations should be guided by local policies, if appropriate). The common investigations to perform are:

• Investigations may be required to exclude non-cardiac causes of chest pain, e.g. chest x-ray (pneumonia), abdominal ultrasound (gall stones), serum amylase (acute pancreatitis).
• Fasting lipids (total cholesterol; HDL cholesterol and triglycerides).
• Fasting glucose.
• Full blood count (to exclude anaemia).
• Resting ECG (can be done in near future; remember if urgent ECG is considered on clinical grounds, patient should almost certainly be admitted to hospital). A resting ECG is usually unhelpful in assessing risk, as it is normal in over 90% of patients with recent symptoms of angina.⁴
• Exercise tolerance test (also known as exercise testing or exercise stress testing):
  • Is used routinely in evaluating patients who present with chest pain, in patients who have chest pain on exertion, and in patients with known ischaemic heart disease.⁵ GPs usually only have access to them through referral to chest pain clinics or cardiology clinics.
  • The diagnostic indications are as follows:
    • Assessment of chest pain in patients with intermediate probability for coronary artery disease.
    • Arrhythmia provocation.
    • Assessment of symptoms (for example, presyncope) occurring during or after exercise.
  • Exercise testing has a sensitivity of 78% and a specificity of 70% for detecting coronary artery disease. It cannot therefore be used to rule in or rule out CHD unless the probability of coronary artery disease is taken into account. For example, in a low risk population, such as men aged under 30 years and women aged under 40, a positive test result is more likely to be a false positive than true, and negative results add little new information. In a high risk population, such as those aged over 50 with typical angina symptoms, a negative result cannot rule out ischaemic heart disease, though the results may be of some prognostic value.⁵

Give advice on diet, what to do in the event of further persistent chest pain (dial 999), and all smokers should be offered smoking cessation advice. Drugs to consider:

• Aspirin - patients with a history (or suspected history) of angina should be taking aspirin 75-150mg daily. For patients with contra-indications to aspirin then clopidogrel can be prescribed.
• Beta-blockers - these are effective in reducing symptoms of angina. However they need to be stopped prior to performing an exercise ECG (as maximum heart rate can not be achieved with taking them) so it is not usually appropriate to start a patient on them when they are being referred to a chest pain clinic.
• GTN - All patients with CHD should have either GTN tablets or spray (spray lasts longer so is usually more practical to prescribe). Sublingual GTN is still the best first-line treatment for an acute anginal attack.
• Statins - Once CHD has been confirmed ideally all patients should have statins prescribed (secondary prevention). Those who turn out not to have CHD should have there risk assessed and may be appropriate for a statin.

According to the National Service Framework for coronary heart disease, all patients with symptoms of angina or suspected angina should receive "appropriate investigation":⁶

• There are a growing number of direct access 'chest pain' clinics in the country, with the majority run by secondary care.
• This enables rapid confirmation of the diagnosis, initiation of treatment, and, where considered appropriate, further investigation and intervention.
• Use of such services should be encouraged, although there is no randomised controlled trial to show that prompt assessment and management actually reduces cardiac morbidity and mortality.²
• Patients should understand that further assessment may lead on to a recommendation for more invasive treatment.