Introduction
Epidemiology
- Incidence: 150.00 cases per 100,000 person-years
- Peak incidence: 60-70 years
- Sex ratio: more common in males 2:1
Condition | Relative incidence |
---|---|
Aortic stenosis | 1.33 |
Angina pectoris | 1 |
Pulmonary arterial hypertension | 0.003 |
<1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Clinical features
- Chest pain
- Classically on the left side of the chest
- May radiate to the left arm or neck
- This may not be present in elderly or diabetic patients
- Dyspnoea
- A minority of patients may complain of dyspnoea rather than chest pain. This is sometimes termed 'equivalent' angina
- Patients may also describe nausea, lightheadedness and fatigue
Investigations
NICE define anginal pain as the following:
- 1. Constricting discomfort in the front of the chest, or in the neck, shoulders, jaw or arms
- 2. Precipitated by physical exertion
- 3. Relieved by rest or GTN in about 5 minutes
- Interpretation:
- Patients with all 3 features have typical angina
- Patients with 2 of the above features have atypical angina
- Patients with 1 or none of the above features have non-anginal chest pain
For patients in whom stable angina cannot be excluded by clinical assessment alone NICE recommend the following (e.g. symptoms consistent with typical/atypical angina OR ECG changes):
- 1st line: CT coronary angiography
- 2nd line: Non-invasive functional imaging (looking for reversible myocardial ischaemia)
- 3rd line: Invasive coronary angiography
Examples of non-invasive functional imaging:
- 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
Management
Medication
- All patients should receive aspirin and a statin in the absence of any contraindication
- Sublingual glyceryl trinitrate to abort angina attacks
- NICE recommend using either a beta-blocker or a calcium channel blocker first-line based on 'comorbidities, contraindications and the person's preference'
- If a calcium channel blocker is used as monotherapy a rate-limiting one such as verapamil or diltiazem should be used.
- If used in combination with a beta-blocker then use a long-acting dihydropyridine calcium-channel blocker (e.g. modified-release nifedipine).
- Remember that beta-blockers should not be prescribed concurrently with verapamil (risk of complete heart block)
- If there is a poor response to initial treatment then medication should be increased to the maximum tolerated dose (e.g. for atenolol 100mg od)
- If a patient is still symptomatic after monotherapy with a beta-blocker add a calcium channel blocker and vice versa
- If a patient is on monotherapy and cannot tolerate the addition of a calcium channel blocker or a beta-blocker then consider one of the following drugs: a long-acting nitrate, ivabradine, nicorandil or ranolazine
- If a patient is taking both a beta-blocker and a calcium-channel blocker then only add a third drug whilst a patient is awaiting assessment for PCI or CABG
Nitrate tolerance
- Many patients who take nitrates develop tolerance and experience reduced efficacy
- The BNF advises that patients who develop tolerance should take the second dose of isosorbide mononitrate after 8 hours, rather than after 12 hours. This allows blood-nitrate levels to fall for 4 hours and maintains effectiveness
- This effect is not seen in patients who take modified-release isosorbide mononitrate
Complications
- Acute coronary syndrome
- Myocardial infarction
- Unstable angina
- Arrhythmias
Patients may also develop complications secondary to the medication they are taking.