Background: The effect of alirocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor, on coronary plaque burden in patients with familial hypercholesterolemia has not been addressed. Our aim was to assess changes in coronary plaque burden and its characteristics after treatment with alirocumab by quantification and characterization of atherosclerotic plaque throughout the coronary tree on the basis of a noninvasive analysis of coronary computed tomographic angiography in asymptomatic subjects with familial hypercholesterolemia receiving optimized and stable treatment with maximum tolerated statin dose with or without ezetimibe. Methods: This study is a phase IV, open-label, multicenter, single-arm clinical trial to assess changes in coronary plaque burden and its characteristics after 78 weeks of treatment with alirocumab in patients with familial hypercholesterolemia without clinical atherosclerotic cardiovascular disease. Participants underwent an initial coronary computed tomographic angiography at baseline and another at 78 weeks. Every patient received 150 mg of alirocumab subcutaneiously every 14 days in addition to high-intensity statin therapy. The main outcome was the change on coronary plaque burden and its characteristics by quantification and characterization of atherosclerotic plaque throughout the coronary tree on the basis of analysis of coronary computed tomographic angiography. Results: The study was completed by 104 patients. The median age was 53.3 (46.2–59.4) years. Of these patients, 54 were women (51.9%). Median low-density lipoprotein cholesterol was 138.9 (117.5–175.3) mg/dL at entry and 45.0 (36.0–65.0) mg/dL at follow-up ( P <0.001). Coronary plaque burden changed from 34.6% (32.5%–36.8%) at entry to 30.4% (27.4%–33.4%) at follow-up ( P <0.001). A significant change in the characteristics of the coronary atherosclerosis was also found: an increase in the proportion of calcified (+0.3%; P <0.001) and mainly fibrous (+6.2%; P <0.001) plaque, accompanied by a decrease in the percentage of fibro-fatty (–3.9%; P <0.001) and necrotic plaque (–0.6%; P <0.001). Conclusions: Treatment with alirocumab in addition to high-intensity statin therapy resulted in significant regression of coronary plaque burden and plaque stabilization on coronary computed tomographic angiography over 78 weeks in these groups of patients with familial hypercholesterolemia without clinical atherosclerotic cardiovascular disease. ARCHITECT (Effect of Alirocumab on Atherosclerotic Plaque Volume, Architecture and Composition) could link and explain ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) results. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05465278.

Familial hypercholesterolemia (FH) is a common genetic disorder, clinically manifested since birth, and associated with very high levels of plasma LDL-cholesterol (LDL-c), xanthomas, and premature coronary heart disease. Its early detection and treatment reduces coronary morbidity and mortality. Despite effective treatment being available, FH is under-diagnosed and under-treated. Identification of index cases and cascade screening using LDL-c levels and genetic testing are the most cost-effective strategies for detecting new cases and starting early treatment. Long-term treatment with statins has decreased the vascular risk to the levels of the general population. LDL-c targets are < 130 mg/dL for children and young adults, <100mg/dL for adults, and < 70 mg/dL for adults with known coronary heart disease or diabetes. Most patients do not to reach these goals, and combined treatments with ezetimibe or other drugs may be necessary. When the goals are not achieved with the maximum tolerated drug treatment, a reduction ≥ 50% in LDL-c levels can be acceptable. Lipoprotein apheresis can be useful in homozygous, and in treatment-resistant severe heterozygous, cases. This Consensus Paper gives recommendations on the diagnosis, screening, and treatment of FH in children and adults, and specific advice to specialists and general practitioners with the objective of improving the clinical management of these patients, in order to reduce the high burden of coronary heart disease.