Introduction
Angina pectoris describes the clinical syndrome of chest pain on exertion secondary to myocardial ischaemia. This is due to narrowing of the arteries secondary to coronary heart disease.
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
Features of stable angina pectoris:
- 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 updated it's guidelines in 2016 on the 'Assessment and diagnosis of recent onset chest pain or discomfort of suspected cardiac origin'.
NICE define anginal pain as the following:
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):
Examples of non-invasive functional imaging:
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
The management of stable angina comprises lifestyle changes, medication, percutaneous coronary intervention and surgery. NICE produced guidelines in 2011 covering the management of stable angina
Medication
Nitrate tolerance
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
Patients with angina pectoris may go on to develop:
Patients may also develop complications secondary to the medication they are taking.
- Acute coronary syndrome
- Myocardial infarction
- Unstable angina
- Arrhythmias
Patients may also develop complications secondary to the medication they are taking.