Inclusion Criteria:  Refractory Angina Pectoris:  Stable angina pectoris CCS class III or IV, with a minimum of 5 episodes of angina pectoris over the course of one week, during a minimum period of three months prior to screening Coronary angiogram (CAG) performed within the last 12 months showing significant coronary artery disease defined as at least one coronary artery stenosis of >75% or 50 - 75% with proven ischaemia (see below), not suitable for revascularisation. Confirmed by one (or two in case of doubt) interventional cardiologist based on CAG images. Optimal anti-anginal medication. Patients should at least use the maximal tolerable dose of a b-blocker, calcium channel blocker and short- and/or long-acting nitrate. If the patient doesn't use one of these groups of medication the reason (side-effects) should be clear.  Proven ischemia:  MIBI-SPECT: summed stress score (SSS) of at least 1, in combination with summed difference score (SDS) of at least 1 (1-4 mild ischaemia, > 4 moderate to severe ischaemia). FFR: < 0.75, with no intervention options (determined by interventional cardiologist) MRI perfusion: ≥ 1 segment of subendocardial hypoperfusion during stress perfusion, not present at rest and no matching fibrosis (using 16 segment AHA heart model) PET: SSS score of at least 1, in combination with SDS score of at least 1 (1-4 mild ischaemia, > 4 moderate to severe ischaemia). No revascularisation (PCI and/or CABG) performed between ischaemia testing and study inclusion. Age > 18 years  Exclusion Criteria:  Acute coronary syndrome (ACS) during the three month period prior to screening Life expectancy less than 12 months Inability to perform a 6-minute walking test Inability to give informed consent No proven ischemia Spinal cord disease which could prevent correct positioning of the lead in the epidural space; to be determined by the anaesthesiologist performing the implantation Anticoagulation therapy that cannot be stopped/bridged prior to spinal cord stimulator implantation Inadequate paraesthesia coverage, during implantation, of the thoracic region where angina complaints are localized Pregnancy Mild Cognitive Impairment or dementia Concomitant symptomatic valvular heart disease including severe aortic stenosis and/or regurgitation, severe mitral valve stenosis and/or regurgitation or severe tricuspid valve regurgitation.