Microvascular Dysfunction Assessment to Predict Left Ventricular Reverse Remodeling

Inclusion Criteria: * Male or female, aged \>18 years * First diagnosis of idiopathic DCM (defined according to the most recent ESC Guidelines) with LVEF ≤ 40% 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 angiographically intermediate disease \[50%-70%\] with impaired FFR or as angiographically severe disease \[\>70%\] in 1 or more epicardial vessels) * History of previous myocardial infarction, percutaneous revascularization or coronary-aortic bypass graft (CABG) surgery * Valvular heart disease (rheumatic heart disease, severe aortic stenosis, severe aortic regurgitation, severe primary mitral regurgitation) * Infective endocarditis * Congenital heart disease * Peripartum cardiomyopathy * Acute myocarditis (detected by endomyocardial biopsy - histological criteria - or by CMR - Lake Louis criteria) and pericarditis * Persistent tachyarrhythmias (documented persistent high-rate supraventricular arrhythmias) * Excessive alcohol intake (\>80 g/die for at least five years) * History of chemotherapy (anthracycline therapy, cumulative dosages \>250 mg/m2) * History of uncontrolled arterial hypertension (blood pressure \>160/100 mmHg) * 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 adenosine * Chronic resting O2 sa…