Vascular Effects of Alirocumab in Acute MI-Patients

Inclusion Criteria: * Male or female, age ≥18 years at screening; * Acute myocardial infarction: acute ST-segment elevation myocardial infarction (STEMI) with pain onset within ≤24h, or non-ST segment elevation myocardial infarction (NSTEMI), with at least one coronary segment (culprit lesion) requiring PCI; * LDL-C ≥70 mg/dL (≥1.8 mmol/L) assessed prior to, or during PCI in patients who have been receiving any stable statin regimen within ≥ 4 weeks prior to enrollment; OR LDL-C ≥125 mg/dL (≥3.2 mmol/L) in patients who are statin-naïve or have not been on stable statin regimen for ≥ 4 weeks prior to enrollment; * At least two major native coronary arteries ("target vessels") each meeting the following criteria for intracoronary imaging immediately following the qualifying PCI procedure: Angiographic evidence of \<50% reduction in lumen diameter by angiographic visual estimation; * Target vessel deemed to be accessible to imaging catheters and suitable for intracoronary imaging in the proximal (50mm) segment ("target segment"); * Target vessel may not be a bypass (saphenous vein or arterial) graft or a bypassed native vessel; * Target vessel must not have undergone previous PCI within the target segment; * Target vessel is not candidate for intervention at the time of qualifying PCI or over the following 6 months in the judgment of the Investigator; * Hemodynamic stability allowing the repetitive administration of nitroglycerine; * Ability to understand the requirements of the study and to provide informed consent; * Willingness to undergo follow-up intracoronary imaging. Exclusion Criteria: * Left-main disease, defined as ≥50% reduction in lumen diameter of the left main coronary artery by angiographic visual estimation; * Three-vessel disease, defined as ≥70% reduction in lumen diameter of three major epicardial coronary arteries by angiographic visual estimation or in major branches of one or more of these arteries, irrespective of the localization (proximal 50mm or more distal localization) of the obstructive lesions; * History of coronary artery bypass surgery; * "Thrombolysis In Myocardial Infarction" (TIMI) flow \<2 of the infarct-related artery after PCI; * Unstable clinical status (hemodynamic or electrical instability); * Significant coronary calcification or tortuosity deemed to preclude IVUS, NIRS and OCT evaluation; * Uncontrolled cardiac arrhythmia, defined as recurrent and symptomatic ventricular tachycardia or atrial fibrillation with rapid ventricular response not controlled by medications in the past 3 months prior to screening; * Severe renal dysfunction, defined by estimated glomerular filtration rate \<30 ml/min/1.73m2; * Active liver disease or hepatic dysfunction; * Known intolerance to rosuvastatin OR known statin intolerance; * Known allergy to contrast medium, heparin, aspirin, ticagrelor or prasugrel; * Known sensitivity to any substances to be administered, including known statin intolerance; * Patients who previously received alirocumab or other PCSK9 inhibitor; * Patient who received cholesterol ester transfer protein inhibitors in the past 12 months prior to screening; * Treatment with systemic steroids or systemic cyclosporine in the past 3 months; * Known active infection or major hematologic, metabolic, or endocrine dysfunction in the judgment of the Investigator; * Planned surgery within 12 months; * Patients who will not be available for study-required visits in the judgment of the Investigator; * Current enrollment in another investigational device or drug study; * History of cancer within the past 5 years, except for adequately treated basal cell skin cancer, squamous cell skin cancer, or in situ cervical cancer; * Estimated life expectancy less than 1 year; * Female of childbearing potential (age \<50 years and last menstruation within the last 12 months), who did not undergo tubal ligation, ovariectomy or hysterectomy.