Study of Lesion-Specific Invasive Haemodynamic Angina Thresholds

Inclusion Criteria: 1. Eligibility for PCI due to angina or angina-equivalent symptoms on exertion 2. 2 severe epicardial stenoses in a major coronary artery, defined as: 1. ≥70% stenosis in a coronary artery with ≥2.5mm diameter, on invasive coronary angiography (ICA) 2. Severe stenosis in a vessel with ≥2.5mm diameter, on CTCA 3. Evidence of ischaemia on an invasive or non-invasive test, including: 1. Physiological test during invasive coronary angiography (ICA) 2. Dobutamine stress echocardiography (DSE) 3. Stress perfusion cardiac magnetic resonance (CMR) 4. Myocardial perfusion scintigraphy (MPS) 5. Fractional flow reserve computed-tomography (FFR-CT) Exclusion Criteria: 1. Age \<18 years 2. Acute coronary syndrome within 3 months 3. Previous coronary artery bypass graft 4. Significant left main stem disease 5. Single lesion amenable to PCI 6. Chronic total occlusion of the target artery 7. Moderate to severe valve disease 8. LVEF ≤40%, contraindication to PCI or drug-eluting stents 9. PCI performed with drug-eluting balloons without stenting 10. Contraindication to antiplatelet therapy 11. Contraindication to adenosine 12. Physical inability to exercise with an ergometer 13. Femoral artery access 14. Pregnancy 15. Inability to consent