The new NICE clinical guideline (CG) on Management of stable angina1 (CG126) gives concise and practical recommendations based on systematic reviews of the best available evidence for the treatment of stable angina.
Importance of stable angina
Chronic stable angina pectoris is a common problem in the UK, with a prevalence of approximately 2 million people who have or have had angina and an annual incidence of 28,000.2 Each year about 1% of the population of the UK consult their general practitioners about angina. The greatest proportion of the nearly £700 million annual direct cost of angina relates to hospital bed occupancy and revascularisation procedures.3 Stable angina is associated with a low, but appreciable risk of acute coronary events and increased mortality.1
Need for the guideline
Inconsistencies in the management of stable angina have been documented across Europe and the UK,4 and a guideline that provides clear guidance to reduce the evidence–practice gap is welcome.1
The new guideline on stable angina from NICE, CG126, should be read in conjunction with other recent NICE guidance on Chest pain of recent onset (CG95).5 In my opinion these two guidelines should have been produced together, allowing for inclusion of algorithms encompassing both diagnosis and management, which would have simplified understanding and implementation for clinicians. The diagnostic guideline (CG95) represents a paradigm shift from exercise testing for all, to diagnosis based either on clinical assessment or on additional testing using computerised tomography calcium scoring, functional testing, or invasive coronary angiography guided by a scoring system estimating likelihood of coronary artery disease.5
What does the guidance cover?
Guidance from NICE on the management of stable angina includes:1
- information and support for people with angina
- prevention and treatment of episodes of angina
- pharmacological treatment, including general principles for treatment of patients with stable angina, selecting drugs for symptom control and those for secondary prevention of cardiovascular disease (CVD)
- investigation and revascularisation including when symptoms are and are not controlled satisfactorily on optimal medical treatment, and general principles of revascularisation
- management of stable angina that has not responded to treatment (refractory angina)
- cardiac syndrome X.
Information and support
After confirming a diagnosis of stable angina using NICE CG95,5 the new NICE guideline on the management of stable angina emphasises the importance of patient and carer education, explaining the long-term course and management of stable angina, exploring and correcting misconceptions, and assessing the person’s need for lifestyle advice. They should be advised to seek professional help if there is a sudden worsening in the frequency or severity of their angina.1
Lifestyle changes should include:1
- promotion of a healthy diet with adequate intake of fish, fruit, and vegetables
- exercise as tolerated
- weight loss
- smoking cessation.
Patients should be advised that there is no evidence for any benefit in prescribing fish oil or multivitamins in the treatment of stable angina.1
The Guideline Development Group for CG126 recognised that intermediate outcomes, such as changes in diet and exercise, indicate potential benefit, but considered that harder outcomes were required if they were to recommend rehabilitation to the NHS as standard treatment for people with stable angina6—a statement that may be controversial in the minds of advocates of this service7 and of those healthcare professionals currently providing this service to their patients!
Prevention and treatment
NICE CG126 offers clear and useful tips on preventing and treating episodes of angina. There are recommendations for patients with stable angina on:
- administration of short-acting nitrates, and their use before planned exercise or exertion
- side-effects that might occur after taking a short-acting nitrate—e.g. flushing, headache, or light headedness (sit down or hold on to something in case of light headedness).
Patients with stable angina who are taking a short-acting nitrate should be advised to:
- take a second dose after 5 minutes if the pain has not gone
- call an emergency ambulance if there is still chest pain after two doses of glyceryl trinitrate separated by 5 minute intervals.
This advice should be clearly communicated to patients, and all healthcare staff should adopt it uniformly.
The use of first-line drug therapy, beta blockers or calcium-channel blockers alone or in combination for treatment of stable angina, has been clarified. Doses of all drugs should be titrated to the optimal licensed dose to control symptoms.
There is no evidence that beta blockers are more effective than calcium-channel blockers in stable angina. I believe QOF criteria, which only target beta-blocker use in stable angina, should now be expanded to include calcium-channel blockers.
NICE CG126 recommends consideration (depending on co-morbidities, contraindications, the patient’s preference, and cost) of a long-acting nitrate or one of the newer anti-anginal medications—ivabradine, nicorandil, or ranolazine—as monotherapy when first-line drugs are either contraindicated or not tolerated. These agents may also be considered as an add-on therapy to one of the first-line drugs if symptoms are not controlled with a beta blocker or calcium channel blocker, and the other first-line agent is contraindicated or not tolerated. A third drug should only be offered to a patient whose symptoms remain uncontrolled after two other agents have been tried and if the patient is awaiting revascularisation or the latter is inappropriate or unacceptable. Patients whose symptoms are well controlled on optimal drug treatment (one or two anti-anginal drugs) should not be offered a third anti-anginal drug.1
Guidelines from the American College of Cardiology and American Heart Association Task Force go as far as suggesting target heart rates of 55–60 beats per minute (bpm) (and 50 bpm for severe angina) with beta blockade in stable angina.8 I believe heart rate control9 should be considered in symptom relief of stable angina, but this has not been addressed in the NICE guideline.
Secondary prevention of cardiovascular disease
The guideline recommends consideration of:
- 75 mg/day aspirin for patients with stable angina—any risk of bleeding must be taken into account
- the use of statins in line with recommendations (CG6710)
- treatment of hypertension (CG12711).
The above recommendations are uncontroversial. However, the suggestion that angiotensin-converting enzyme inhibitors should only be offered to patients with stable angina and diabetes (or other indicated conditions, e.g. heart failure, in line with appropriate NICE guidance) may surprise some clinicians, but does accurately reflect the existing evidence base. Patients with suspected cardiac syndrome X should not be routinely offered drugs for secondary prevention, although treatment for stable angina should be continued for these patients if it improves their symptoms.
Patients whose angina is well controlled on therapy should have the opportunity to discuss: their prognosis before and after further investigation; the benefits of such investigations; possible revascularisation; and the likelihood that they may have left main stem disease or three-vessel disease.1 In these latter cases, coronary artery bypass graft (CABG) should be considered, as well as the process and risks of investigations, possible benefits and gains, as well as potential survival gains. There is no randomised trial evidence that revascularisation is better than optimal medical therapy, but cohort studies suggest benefit for revascularisation in the latter two groups.6 I do not think the guideline is very clear about how to predict prognosis, communicate it to patients, or when GPs should refer patients on to a multidisciplinary team for further investigation or management.
NICE CG126 highlights the importance of optimising medical therapy before considering revascularisation. It recommends optimal drug treatment comprising one or two anti-anginal drugs as needed, with the addition of drugs as necessary for secondary prevention of CVD. Revascularisation (CABG or percutaneous coronary intervention [PCI] as appropriate) should be considered for patients with stable angina whose symptoms are not satisfactorily controlled after optimal medical treatment. This may come as a shock to many interventionalist cardiologists who need to recognise that the evidence base for revascularisation on prognostic grounds is based on old trials conducted before the introduction of secondary prevention, which also improves prognosis.
For those patients who remain symptomatic after optimal medical therapy, and who have diabetes, or are aged >65 years, or who have anatomically complex three-vessel disease (with or without left main stem involvement), a review of the diagnosis together with re-appraisal of anatomical and/or functional tests is needed before offering revascularisation with CABG or PCI. This is best decided by a multidisciplinary team, which should include a cardiologist and a cardiac surgeon.1
Refractory stable angina
The section on stable angina that has not responded to treatment provides useful guidance on comprehensive re-evaluation and advice for the patient.
Many clinicians running refractory angina clinics may not agree with advice not to use transcutaneous electrical nerve stimulation, enhanced external counterpulsation, or acupuncture for patients with stable angina, but the guidance is based on the lack of evidence that these procedures reduce frequency of angina.6
The guideline and executive summary clearly outline key priorities for implementation. This guideline is unlikely to result in significant increases in resource use in the NHS. Conversely, it may reduce NHS costs by reducing the need for revascularisation when symptoms are satisfactorily controlled with optimal medical treatment, and increasing awareness of and reduction of inappropriate use of newer more expensive drugs.
Full implementation of the NICE guideline for the benefit of our patients with stable angina will require education of healthcare professionals, modification of attitudes in favour of optimal medical management as the initial treatment strategy, and urgent revision of QOF criteria to reflect guideline recommendations and inform current evidence-based practice in community and secondary care CHD clinics.
The NICE guideline on Management of stable angina recognises limitations in the evidence base, and this is demonstrated by the number of clear research recommendations that have been made in order to inform future updates of the guideline.
This guideline is concise, comprehensive, practical, and user friendly. It is very relevant for primary care, and GPs and practice nurses undertaking stable angina management should at least read the guideline summary in the full guideline, which contains detailed and useful information to aid patient education and management.6
The challenges GPs face in managing stable angina include:
- achieving an accurate and expedient diagnosis
- educating patients and their carers
- establishing patients on evidence-based therapy
- improving quality of life and prognosis
- keeping patients out of hospital.
I believe this guideline addresses these challenges.
- National Institute for Health and Care Excellence. Management of stable angina. Clinical Guideline 126. London: NICE, 2011. Available at: nice.org.uk/guidance/CG126
- British Heart Foundation Health Promotion Research Group. Coronary heart disease statistics: 2010 edition. Available from: www.heartstats.org.uk
- Stewart S, Murphy N, Walker A et al. The current cost of angina pectoris to the National Health Service in the UK. Heart 2003; 89 (8): 848–853.
- Daly C, Clemens F, Sendon J et al on behalf of the Euro Heart Survey Investigators. The initial management of stable angina in Europe, from the Euro Heart Survey. Eur Heart J 2005; 26: 1011–1022.
- National Institute for Health and Care Excellence. Chest pain of recent onset. Clinical Guideline 95. London: NICE, 2010. Available at: nice.org.uk/guidance/CG95
- National Clinical Guidelines Centre. Stable angina: methods, evidence and guidance. London: NCGC, 2011. Available at: www.nice.org.uk/guidance/CG126/Guidance
- Lewin R, Furze G, Robinson J et al. A randomised controlled trial of a self-management plan for patients with newly diagnosed angina. Br J Gen Pract 2002; 52 (476): 194–201.
- Gibbons RJ, Chatterjee K, Daley J. ACC/AHA/ACP-ASIM guidelines for the management of patients with chronic stable angina: executive summary and recommendations. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (committee on management of patients with chronic stable angina). Circulation 1999; 99 (21): 2829–2848.
- Purcell H. Heart rate as a therapeutic target in ischaemic heart disease. Eur Heart J 1999; 1: 58–63.
- National Institute for Health and Care Excellence. Lipid modification: cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. Clinical Guideline 67. London: NICE, 2010. Available at: www.nice.org.uk/guidance/CG67
- National Institute for Health and Care Excellence. Hypertension: clinical management of primary hypertension in adults. Clinical Guideline 127. London: NICE, 2011. Available at: www.nice.org.uk/guidance/CG127 G