Abstract 12279: Cardiovascular Disease Progression in Children With Homozygous Familial Hypercholesterolemia Despite Early Diagnosis on a Genetic Cascade Screening Program

Abstract

Introduction: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by extremely elevated low-density lipoprotein cholesterol (LDL-c) and very high risk of premature atherosclerotic cardiovascular (ASCVD) and aortic/supraortic valve heart diseases (VHD). The study aim was to examine clinical and biochemical trajectories of a cohort of HoFH patients since childhood. Methods: In this longitudinal study we assessed the incidence of manifest or subclinical ASCVD (coronary or carotid) and VHD as well as plasma lipids in a cohort of HoFH subjects during a 12.9 ± 9.6 years follow-up. Results: From the 868 individuals ≤19 y-old (at baseline) that were genotyped on a genetic cascade screening program, 420 (48.4%) had an FH mutation. From children bearing mutations, 12 were true homozygotes and 1 was compound heterozygote (53.8% females, mean age 7.5 ± 4.1 years at the first visit). During follow-up all were on statin and ezetimibe therapies, and the mean final dose of atorvastatin was 56 ± 27 mg/d (n=10); and rosuvastatin, 26 ± 17 mg/d (n=3). Initial and on treatment LDL-c were 655 ± 177 mg/dL and 399 ± 150 mg/dL, respectively, with a mean 39.1% reduction (-256 mg/dL). None were under LDL apheresis; 2 patients used mipomersen, 2 lomitapide, and 2 are currently using PCSK9 inhibitors. Subclinical cardiovascular disease, either coronary, carotid or in aortic valve, was identified in 38.5% (n=5; mean age 16.4 ± 9.8 years), whereas 30.8% had a clinical cardiovascular event (n=4; mean age 22.8 ± 6.8 years), with 2 deaths. Therefore, 69.3% had either subclinical or manifest cardiovascular disease. Conclusion: Despite early diagnosis and LDL-c reduction HoFH is still marked by an adverse and premature cardiovascular disease progression. Conventional lipid lowering therapies are not adequate to prevent ASCVD and VHD disease course.