Refractory angina pectoris is a major clinical problem characterised by unremitting symptoms of angina (equivalent to severity score class III-IV on the Canadian Cardiovascular Society classification), which are resistant to conventional treatments including nitrates, calcium channel and β adrenoceptor blockade, percutaneous coronary interventions, and coronary artery bypass grafting.1 Although there are limitations in current surveillance systems worldwide, estimates from data on revascularisation and hospital admission suggest a prevalence of refractory angina somewhere between 600 000 and 1.8 million in the United States and an incidence of 30-50 000/year in continental Europe.1 2

Patients with refractory angina experience persistent anginal pain, poor general health status, psychological distress, restriction of activity, and inability to self manage their symptoms—all of which have a negative effect on health related quality of life.1 …