Stable angina is a chronic condition which may persist for years. It affects a significant proportion of the population, and is more common with advancing age. According to the 2006 Health Survey for England, angina affects 8% of men and 3% of women aged 55-64 increasing to 14% and 8% respectively for men and women aged 65-74.1

Symptoms of angina can be alarming and distressing and it is therefore important that patients understand the underlying problem and what therapies are available to improve or abolish their symptoms.

The management of stable angina in all patients should include appropriate lifestyle changes and optimal medical therapy - and in some patients revascularisation. It is important to reassure patients with clinically significant coronary artery disease, both symptomatic and asymptomatic, that for most a combination of lifestyle modification and optimal medical therapy will prove sufficient treatment. However, a minority of patients may also require intervention either by stents or surgery.

In discussions with patients, it is useful to involve appropriate friends or family and to adapt recommendations to the patient’s individual circumstances. For example, whereas some limitation of strenuous exercise in an elderly patient may be appropriate this might be less attractive to younger patients.

Two important evidence-based guidelines have recently been published in this area. In 2010, the European Society of Cardiology

and the European Association for Cardio-Thoracic Surgery (ESC/EACTS) published joint guidelines for myocardial revascularisation.2 In July 2011, NICE published guidelines on the management of stable angina.3

Lifestyle modification

It is vital that patients with obvious precipitating factors that may promote or aggravate underlying coronary artery disease address these with appropriate lifestyle changes.

Cigarette smoking should be stopped and a balanced diet and regular exercise should be encouraged. Weight loss should be strongly advised for those who are significantly overweight and its additional benefits of reducing the risk of developing diabetes (or improving its control) and musculoskeletal problems emphasised.

Patients should also be given general advice about factors that aggravate angina for example:

• cold weather

• heavy exercise

• emotional stress

Advice on appropriate physical exertion and sexual activity should also be included. Patients may have to adapt their expectations to the severity of their symptoms.

Optimal medical therapy

What defines optimal therapy in an individual patient will be dependent on the burden and severity of the underlying coronary artery disease.

A short-acting nitrate for angina prevention and treatment of episodes of angina is recommended. It should be used prophylactically in advance of any exertion.

In terms of secondary prevention, basic therapy includes aspirin and a statin and antihypertensive agents for those with higher blood pressure.

Optimal drug therapy consists of two anti-anginal drugs, such as a beta-blocker or calcium channel blocker as first-line treatment and in preference to other drug therapy unless there are side-effects or contraindications to these.

A third anti-anginal drug is not necessary in those patients whose angina is adequately controlled on dual therapy but should be considered if symptoms remain intrusive. In such situations advice from a cardiologist may be useful.

Investigations

Some consideration should be given to the need for further investigation in patients with angina even if symptoms are appropriately controlled by lifestyle changes and optimal medical therapy. This is because the severity of symptoms does not necessarily correlate with the severity of the underlying disease process.

It is of critical importance to understand that the prognosis of coronary artery disease is strongly linked to the volume of underlying myocardial ischaemia and this cannot be determined simply by the level of symptoms. This should be explained to patients who should be offered further investigation if they wish and should certainly be encouraged in younger patients. It is mandatory in those with obvious changes in their level of symptoms.

A relatively normal exercise test provides considerable reassurance that the patient is at low risk of subsequent adverse cardiac events. In patients who have positive exercise tests further investigation, usually by angiography, should be undertaken.

This can define the number of diseased coronary arteries and in association with simultaneous fractional flow reserve measurements can quantify the functional significance of any particular stenoses in causing ischaemia.

Unless a significant volume of myocardium (>10%) is at risk from ischaemia, there may be no prognostic benefit from revascularisation. However, even in patients in whom there is no significant burden of ischaemia, revascularisation can be justified on symptomatic grounds if the patient remains highly symptomatic despite optimal medical therapy or is intolerant of maximal medical therapy.

Revascularisation

The choice of revascularisation, whether by stents or surgery, has been the subject of much debate and recent guidelines produced jointly by the ESC and EACTS have helped clarify recommendations on when stents or coronary artery bypass grafting (CABG) should be carried out (see tables 1 and 2, opposite).

The guidelines emphasise that the recommendations apply where both therapies are potentially suitable and where the patient is at low risk for surgical intervention.

As the SYNTAX trial24 shows, for the majority of patients with three-vessel coronary artery disease (around 79%) and for almost two thirds of patients with left main stem disease, there is still a clear survival advantage associated with CABG rather than stents and in such patients stents are contraindicated unless the patient is unfit for, or refuses, surgery, see table 2 opposite.

However, for patients with less severe three-vessel coronary artery disease and less severe anatomical forms of left main disease there now appears to be equivalence in terms of survival between CABG and stents, although CABG still remains far more effective in reducing the need for further interventions.

Ongoing management

NICE emphasises the importance of the role of the multidisciplinary team. This should include a non-interventional cardiologist, a cardiac surgeon and an interventional cardiologist. It recommends the team meet regularly to discuss

the risks and benefits of continuing drug treatment or the revascularisation strategy.

Even after intervention, it is mandatory to ensure that the patient remains on optimal medical therapy, usually consisting of at least one antiplatelet agent, a beta-blocker and a statin. Additional therapy may be necessary depending on the severity of the coronary artery disease.

Conclusion

Most patients with chronic stable angina can be treated satisfactorily these days with a combination of lifestyle changes and optimal medical therapy. For a smaller cohort of patients with more severe disease, revascularisation may be appropriate. For patients with the most severe forms of coronary artery disease there is still a prognostic benefit from coronary artery bypass grafting while stents may be appropriate in less severe forms of disease.