Patient description: A 46-year-old man presents with dizziness and frequent headaches. He has a family history of CAD, but no other cardiovascular risk factors such as smoking, high blood pressure, and diabetes mellitus and is physically active. The patient's LDL-C and HDL-C levels were 545 and 53 mg/dL, respectively. His fasting glucose and triglyceride levels (85 and 158 mg/dL, resp.) were within normal limits. The patient reported no use of lipid-lowering medications. Neck auscultation revealed a systolic murmur 3+/6+ in the neck, radiating to the skull. Ultrasonography of the carotid arteries, revealed severe stenosis in the left internal carotid artery (LICA), as well as moderate stenosis in the right internal carotid artery (RICA) estimated between 40% and 50%. For the LICA, the peak-systolic (PSV) and end-diastolic velocity (EDV) cutoff values were 208.5 cm/s and 54.5 cm/s, respectively; RICA PSV was 91.72 cm/s and RICA EDV was 37.37 cm/s. Plaque was observed in the anterior and posterior walls of the internal carotid artery and common carotid artery, which were characterized as bulky plates extending to the middle third of the internal coronary arteries (ICAs) and as predominantly echogenic and hyperechoic, with less than 50% of the area being echolucent with uneven surfaces.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Hypercholesterolemia Either A, B, C, D, or E below and not adequately controlled with a maximally tolerated dose of statin with or without other LMTs, all at stable doses for at least 4 weeks prior to the screening visit (Week-3): A. Participants suffering from heterozygous familial hypercholesterolemia (heFH) with LDL-C concentrations greater than or equal to (>=)160 mg/dL (4.14 millimoles per liter [mmol/L]) despite treatment. B. Participants suffering from heFH with LDL-C concentrations >=130 mg/dL (3.36 mmol/L) despite treatment and two or more CV risk factors among this list LDL-C greater than (>) 250 milligrams per deciliter (mg/dL) (6.46 mmol/L) at the time of the familial hypercholesterolemia (FH) diagnosis (before treatment) Family history of premature-onset coronary heart disease (CHD; first-degree male relative with onset before age 55 years; first-degree female relative with onset before age 65 years) Metabolic syndrome HDL-C less than (<) 40 mg/dL (1.03 mmol/L) Hypertension (blood pressure >140/90 mmHg or drug treatment) Lipoprotein a (Lp[a]) >=50 mg/dL (1.78 µmol/L) Tendon xanthoma. C. Participants suffering from heFH with LDL-C concentrations >=130 mg/dL (3.36 mmol/L) despite treatment and one of the following characteristics Established CHD or other cardiovascular disease (CVD; history of acute myocardial infarction, ischemic stroke, peripheral arterial disease, coronary or peripheral arterial revascularization, stable or unstable angina, transient ischemic attack, carotid artery stenosis >=50 percent (%), or aortic abdominal aneurysm) Drug-treated type 2 diabetes mellitus or type 1 with target organ damage  Not on a stable dose of LMT (including statin) for at least 4 weeks prior to the screening visit (Week -3) and from screening to enrollment. Use of a fibrate other than fenofibrate within 4 weeks of the screening visit (Week-3) or between screening and enrollment. Daily doses above atorvastatin 80 mg, rosuvastatin 40 mg, or simvastatin 40 mg (except for participants on simvastatin 80 mg for more than one year, who were eligible). Use of statin other than simvastatin, atorvastatin, or rosuvastatin prior to the screening visit (Week-3) or between screening and enrollment, except when there was a documented reason for intolerance to the above mentioned potent statins (in which case the use of a different statin was allowed). Fasting serum TG >400 mg/dL (>4.52 mmol/L) at the screening visit (Week -3). Uncontrolled hypertension (>180 mmHg systolic and/or >110 mmHg diastolic at randomization visit). New York Heart Association Class III or IV congestive heart failure persisting despite treatment. History of hemorrhagic stroke. Liver transaminases >3 times the upper limit of normal. Laboratory evidence of current hepatitis B or C infection. Creatine kinase >3 times the upper limit of normal. Estimated glomerular filtration rate <30 mL/min/1.73 m^2. Pregnant or breastfeeding woman or with childbearing potential without appropriate contraception. Male participant with a female partner of childbearing potential not protected by a highly-effective method(s) of birth control. Participants eligible for enrollment into an ongoing clinical study of alirocumab conducted at the same investigational site. Hypersensitivity to alirocumab or any of the excipients. The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial