Inclusion Criteria:  Inclusion criteria for the STEMI group:  ST segment elevation MI ≥7 days treated by angioplasty of the left anterior descending (LAD) artery Scheduled to undergo angiography for fractional flow reserve (FFR) assessment of a lesion other than the infarct-related artery.  Inclusion criteria for the control group:  patients undergoing non-urgent coronary angiography for stable angina or silent ischemia with measure of the FFR on one or more vessels (intermediate lesion <90% without proven ischemia) absence of any significant lesion on the LAD (as assessed by angiography or FFR>0.8)  Inclusion criteria for both groups:  Written informed consent Affiliation to a social security regimen (or beneficiary thereof).  Exclusion Criteria:  Target vessel (LAD) not permeable. FFR <0.8 in the LAD Coronary spasm Left ventricular ejection fraction <0.50 or a history of anterior MI in patients in the control group Hypertrophic cardiomyopathy Severe valvular heart disease History of coronary artery bypass graft Patients with limited legal capacity or patients under guardianship/tutorship Patients with anticipated poor compliance as assessed by the investigator Patients not affiliated to any social security regime. Pregnant women. Subjects within the exclusion period of another clinical trial as noted in the national registry of research volunteers