Angina module 7: revascularisation in stable coronary artery disease

Click any image to enlarge

The revascularisation option in stable angina

Various European,1 UK2 and US3 guidelines have been published advising on the use of revascularisation, i.e. percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) in patients with occlusive coronary artery disease (CAD) (see practice point). In most European countries, angioplasty now accounts for at least 70% of all revascularisations.4 PCI has become one of the most frequently performed therapeutic interventions in medicine, and progress has resulted in a steady decline of periprocedural adverse events, resulting in excellent outcomes.1

General recommendations on revascularisation

National Institute for Health and Clinical Excellence (NICE) guidance on the treatment of stable angina2 highlights, in its list of key priorities for implementation:

  • The use of revascularisation (CABG or PCI) for patients whose symptoms are not satisfactorily controlled using optimal medical treatment (OMT).

When either procedure would be appropriate, the guidance recommends, it is important to explain to the patient “the risks and benefits of PCI and CABG for people with anatomically less complex disease whose symptoms are not satisfactorily controlled with [OMT]”. If the patient does not express a preference, NICE points to evidence suggesting that “PCI may be the more cost-effective procedure in selecting the course of treatment”.

Practice point

In cases where either procedure would be appropriate, the guidelines also recommend considering the potential survival advantage of CABG over PCI for patients with multi-vessel disease whose symptoms are not satisfactorily controlled with OMT, and who:

  • have diabetes
  • are over 65 years or
  • have anatomically complex three-vessel disease, with or without involvement of the left main stem.

There is much current interest in which patients are likely to benefit more from PCI, or from coronary artery bypass graft (CABG) surgery.  Figure 1 shows a flow-chart of revascularisation strategies in chronic stable angina.5  As angioplasty techniques, and in particular equipment, have continued to develop, e.g. drug eluting stents, the distinction between these two treatment options for patients with two- or three-vessel disease has become less clear.

Figure 1. Flow chart of revascularisation strategies in chronic stable angina.

In summary

Coronary revascularisation should be considered in patients with stable angina pectoris who either remain symptomatic despite or intolerant of OMT. High-risk patient groups with stable CAD who may especially derive benefit from coronary artery bypass grafting (CABG) include those with:

  • lesions involving the left main stem or proximal left anterior descending (LAD) coronary arteries, particularly where there is left ventricular systolic dysfunction
  • a large territory of reversible ischaemia demonstrated on functional testing, such as myocardial perfusion imaging.
Figure 2. Rates of PCI and CABG procedures in the UK from 1991–2013

In the UK, 92,589 PCI and nearly 16,791 CABG procedures were performed in 2013 (figure 2). Approximately 34.4% of the PCI procedures were performed on patients with stable CAD.6 Recent data points also towards a wide variability in PCI rates throughout Europe (figure 3).7

US studies have shown a steady decline in annual CABG utilisation rates between 2001 and 2008, despite there being no significant change in PCI rates.8 Data from hospitals in the Nationwide Inpatient Sample showed that the annual CABG surgery rate decreased by over 600 per million adults per year in that period.

Figure 3. Coronary angioplasty as a share of total revascularisation procedures, 2000 to 2012 (or nearest year)