Insulin Resistance and Coronary Microvascular Dysfunction in Patients with Myocardial Ischemia and Non-obstructive Coronary Artery Disease

Inclusion Criteria: * Aged over 18 years. * Cardiac chest pain with evidence of myocardial ischemia at noninvasive myocardial stress imaging and clinical indication to diagnostic coronary angiography * Willing and able to give informed consent for participation in the study Exclusion Criteria: * Obstructive CAD (defined as more than 70% luminal stenosis and/or FFR ≤0.80 in 1 or more epicardial vessels). * History of previous myocardial infarction, percutaneous revascularization or coronary-aortic bypass graft (CABG) surgery. * Diagnosis of type II diabetes. * BMI ≥ 35 kg/m2. * Stage IV and V of chronic kidney disease (eGFR ≤ 30 ml/min, estimated through CKD - EPI Creatinine Equation). * Allergy or other contraindication to iodinated contrast and/or gadolinium and/or adenosine. * Chronic resting O2 saturation ≤ 85%. * Pregnancy or suspected pregnancy.