AID Post-PCI Angina is as an observational, prospective, single-cohort, multicenter study designed to investigate the causes and origins of post-PCI angina by using the advance invasive diagnosis (AID) strategy combining with angiography derived physiology (ADP) in an all-comers population of patients with post-PCI angina referred for invasive coronary angiography. An all-comers population of patients with a history of previous percutaneous coronary intervention (PCI), who presented with angina or documented myocardial ischemia by non-invasive testing and are referred for invasive coronary angiography (ICA) will be enrolled. ICA will be performed with the application of the structure AID strategy to evaluate both obstructive and non-obstructive cause of myocardial ischemia. Then, angiography derived physiological assessment of epicardial coronary artery using functional coronary angiography in each vessel will be performed in both index procedure and the previous procedure in all patients. By combining information obtained from both procedures, the causes and origins of post-PCI angina will be made. Treatment will be decided by the operators according to the result. Patients will complete the Seattle Angina Questionnaire (SAQ) at baseline and at 1, 6, and 12 months after the procedure. The main hypothesis of this study states that, in patients with post-PCI angina referred to ICA, the application of the structured AID strategy combining with angiography derived physiology (ADP) will lead to a high diagnostic yield in identifying the origins of obstructive disease and causes of post-PCI angina.

AID Post-PCI Angina is as an observational, prospective, single-cohort, multicenter study intended to investigate for the causes and origins of post-PCI angina by using the advance invasive diagnosis (AID) strategy combining with angiography derived physiology (ADP) in an all-comers population of patients with post-PCI angina referred for invasive coronary angiography. Secondary objective is to investigate the benefits of applying the AID strategy in the improvement of angina symptoms at 6 months, evaluated by the Seattle Angina Questionnaire (SAQ). This study is a multicenter study and will be conducted in 5 hospitals across Spain.

An all-comers population of patients with a history of previous percutaneous coronary intervention (PCI) with drug eluting stent (DES), bare metallic stent (BMS), or drug coated balloon (DCB) due to acute coronary syndrome or chronic coronary syndrome, who presented with angina or documented myocardial ischemia by non-invasive testing and are referred for ICA at participating centers, will be enrolled in the study.

After acquiring patient's informed consent, ICA will be performed with the application of the structure AID strategy to evaluate both obstructive and non-obstructive cause of myocardial ischemia. AID strategy begins with invasive coronary angiography. Angiographically severe-grade stenosis (≥90%) can be safely considered as cause of a myocardial ischemia without further physiological assessment. Conversely, by means of a pressure guidewire, intermediate-grade stenosis would be evaluated with fractional flow reserve (FFR) and/or non-hyperaemic pressure ratios (NHPR) in order to determine if they are physiologically relevant. Those patients with non-obstructive CAD or normal epicardial coronary arteries would undergo functional coronary tests to investigate the presence of microcirculatory and vasomotor coronary disorders, which would account for non-obstructive causes of ischaemia. Patient's angiograms in both index procedure and previous PCI will be assessed by functional coronary angiography using the AngioPlus Core software (Pulse Medical Technology, Shanghai, China) for angiography derived physiology (ADP). By combining the results from the AID strategy and ADP, origin of obstructive disease can be defined as progression of CAD, post-PCI residual disease, suboptimal stenting and in stent restenosis (ISR.

Treatment will be decided by the operators according to the result. Patient will be follow-up at 1, 6, and 12 months after the procedure. At each follow-up, patients will complete the Seattle Angina Questionnaire (SAQ) to evaluate for angina symptom.

Inclusion Criteria:

• Patients with a history of previous percutaneous coronary intervention (PCI) with drug eluting stent (DES), bare metallic stent (BMS), or drug coated balloon (DCB) due to acute coronary syndrome or chronic coronary syndrome, who presented with angina or documented myocardial ischemia by non-invasive testing and are referred for invasive coronary angiography.

Exclusion Criteria:

• Acute myocardial infarction (ST-segment elevation myocardial infarction [STEMI] and non-ST-segment elevation myocardial infarction [NSTEMI]).
• Age < 18 years old.
• Pregnancy.
• Severe left ventricle systolic dysfunction (left ventricular ejection fraction ≤30 %).
• Congestive heart failure with reduced ejection fraction.
• Concomitant severe valvular heart disease.
• Severely decreased renal function (glomerular filtration rate < 30 mL/min/1.73 m2).
• Significant epicardial coronary artery disease unable to be treated by PCI.
• Previous coronary artery bypass grafting (CABG).
• Presence of any anatomic features precluding intracoronary instrumentation with pressure guidewires.
• Contraindications to the administration of adenosine or acetylcholine.

An all-comers population of patients with a history of previous percutaneous coronary intervention (PCI) with drug eluting stent (DES), bare metallic stent (BMS), or drug coated balloon (DCB) due to acute coronary syndrome or chronic coronary syndrome, who presented with angina or documented myocardial ischemia by non-invasive testing and are referred for ICA at participating centers.