Optical Coherence Tomography in Patients With Acute Myocardial Infarction and Nonobstructive Coronary Artery Disease

Inclusion Criteria: * Evidence of myocardial infarction: elevation of troponin to above the laboratory upper limit of normal (ULN) or new ST segment elevation of ≥1mm on 2 contiguous ECG leads or new left bundle branch block * Symptoms of ischaemia (chest pain or anginal equivalent symptoms at rest or new onset exertional anginal equivalent symptoms with concomitant ST-segment depression, T wave inversion or transient ST-segment elevation) * Delivery of an informed consent and compliance with study protocol * Age ≥ 18 years Exclusion Criteria: * Prior diagnosis of obstructive CAD (including history of percutaneous coronary intervention or coronary artery bypass grafting) * Stenosis \>50% of any coronary vessel on invasive angiography * Contraindication to OCT in the opinion of the treating physician * Use of vasospastic agents * Alternate causes of myocardial injury/ischaemia (severe anaemia, hypertensive crisis, acute heart failure, cardiac trauma, pulmonary embolism, etc.) * Severe renal failure (eGFR\<30) * Pregnancy