Active_comparator: Intervention Group - Stratified Medicine

All randomised participants will receive stratified medicine. The subjects will undergo functional coronary angiography involving guidewire-based coronary function tests (interventional diagnostic procedure, IDP) as an adjunct to invasive coronary angiography. The IDP results will be disclosed to the catheter laboratory clinician to clarify endotypes and re-evaluate the clinical diagnosis. Linked guideline-directed medical therapy and lifestyle measures will be recommended based on the endotype. The patient and clinicians responsible for downstream care will not be informed of the randomised group but they will be informed of the endotype and linked treatment plan, in the same way as in the Standard Care control group. They will be blinded to the allocated study arm and IDP findings.

Sham_comparator: Standard Care Group

All randomised participants in this arm will receive standard angiography-guided care. The endotype will be determined based on the angiogram and all of the available clinical information. The participants in this group will also receive the IDP at time of the angiogram. The results of the IDP will be concealed from the catheter laboratory clinician who will be blinded. The cardiac physiologist / clinical scientist will remain unblinded for the purpose of data recording and quality assurance. The sham procedure is intended to be the same as in the Intervention Group. Management of the patient is as per standard of care, with therapy linked to the diagnosis (endotype). The patient and clinicians responsible for downstream care will not be informed of the randomised group but they will be informed of the endotype and linked treatment plan in the same way as in the Intervention Group. They will be blinded to the allocated study arm and IDP findings.