The role of percutaneous coronary intervention (PCI) in patients with ST elevation myocardial infarction (STEMI) is clear (European Society of Cardiology STEMI Guideline 2008).1 Randomised trials comparing primary PCI with fibrinolytic therapy have consistently demonstrated better outcomes and reduced bleeding complications with primary PCI, although data on prehospital lysis versus primary PCI are still awaited (STREAM study). Similarly, non-ST elevation acute coronary syndromes guidelines recommend the use of PCI.2 The guidance is based upon a pooled analysis of randomised trials and the evidence is most compelling in higher-risk patients, but there is no evidence of benefit, and perhaps harm, in low-risk patients.2 3

However, world wide, most PCIs are performed for patients without acute myocardial infarction (MI) and unassociated with a recent acute coronary syndrome. For example, data from the United States indicate that among more than 1–2 million PCI procedures, the majority were performed in patients with stable coronary artery disease.4 In stable coronary disease, as in other clinical conditions, it is appropriate that invasive interventions may be used to relieve symptoms. It is critical that the decision-making process is robust and transparent and that clinicians and patients have a reliable assessment of risks versus benefits of the treatment options. However, evidence suggests that clinicians are overoptimistic about the potential outcome benefits of PCI and overpessimistic about medical management.5 At least half of clinicians surveyed believed that with medical management the outcome for two- and three-vessel disease was worse than the lower 95% confidence boundary based on the evidence.5 Recent data from patients in the USA discloses serious misconceptions. Some patients believed that the PCI in stable angina was being performed as an emergency (33% of patients surveyed), that it would prevent MI (71%) and that it would extend life (66%).6

The …