Revascularisation to treat symptoms of angina
Revascularisation involves either percutaneous coronary intervention (PCI) or coronary-artery bypass surgery (CABG).
Revascularisation is most frequently performed for symptom relief but a small percentage of patients also have a prognostic
benefit (usually those who are at high risk). Stress testing or similar further risk stratification is required in all
patients with stable angina unless co-morbidities would prohibit revascularisation.
Patients who may benefit from revascularisation include:
- Those at high-risk, e.g. patients with symptomatic multi-vessel disease, proximal left anterior descending or left
main artery disease, left ventricular systolic dysfunction, diabetes or a large ischaemic burden (referring to all angina
episodes, including silent angina).2
- Those who have failed to respond to pharmacological treatment, i.e. patient is still experiencing symptoms while
on two anti-anginal drugs.
Secondary prevention measures are still important because PCI does not change the natural history of coronary artery
disease where non-obstructive plaques may suddenly progress to high grade stenosis or even total vessel occlusion.21 Repeat
revascularisation may be necessary after PCI or CABG, but is more common after PCI.21
Optimal medical treatment or revascularisation?
Clinical trial evidence suggests that revascularisation initially provides better symptom control than pharmacological
treatment,21 but in the long-term, it appears that there is little difference between the two approaches to
angina symptom control.
Two large, recent clinical trials have compared the effectiveness of pharmacological treatment to revascularisation
in the management of chronic stable angina. Earlier trials may no longer be relevant to modern clinical practice due
to advances in PCI techniques (e.g. the use of stents) and improvements in the optimal use of medicines for both symptom
control and risk factor reduction.
The Clinical Outcomes Utilising Revascularisation and Aggressive Drug Evaluation (COURAGE) trial was a randomised controlled
trial (RCT) which randomly assigned 2287 patients with angina and significant coronary artery disease to either optimal
medical treatment alone or PCI and optimal medical treatment.22 High-risk patients who were likely to have
a survival benefit from revascularisation (usually CABG) were excluded from the trial. Optimal medical treatment included
medicines to prevent angina; beta blockers, calcium channel blockers, nitrates individually or in combination and an
ACE inhibitor or angiotensin receptor blocker (ARB), as well as an antiplatelet medicine and a statin. The results showed
no significant difference in the risk of death, myocardial infarction, or rates of hospitalisation between the two groups.
Significantly more patients in the PCI group were free of angina at one and three year follow-up, however, by five years
there was no significant difference between the groups.22
A follow-up study using an angina specific health questionnaire compared the quality of life for patients in each group
and found marked improvement in the health status of patients in both groups.23 Although patients in the PCI
group initially reported greater benefit, by three years there was no significant difference in health status between
the two groups. The most benefit with PCI, as indicated by quality of life measures, was in a subgroup of patients who,
at baseline, had the most severe angina.23
The Bypass Angioplasty Revascularisation Investigation 2 Diabetes (BARI) trial, also a RCT involving 2368 patients
randomised to PCI and intensive medical treatment or intensive medical treatment alone, reported similar results to those
reported for the COURAGE trial, with no significant difference in the primary outcome of death from any cause or in the
rate of major cardiovascular events.24