Hospitalized Children With Familial Hypercholesterolemia and COVID-19: A Case for Preventive Anticoagulation.

Abstract

Heterozygous familial hypercholesterolemia (HeFH) affects about one in 200 to 250 persons or over 30 million people worldwide, of whom about 20–25% are children and adolescents (1, 2). In those with HeFH, the level of serum low-density lipoprotein cholesterol (LDL-C) is elevated about two-fold from birth (3). If left untreated, the severe hypercholesterolemia causes pre-mature atherosclerosis. The standard treatment in HeFH children is statin therapy, which should start when the child is between 8 and 12 years of age (4). Homozygous familial hypercholesterolemia (HoFH) is the severe form of familial hypercholesterolemia (FH) affecting approximately 1 in 300,000 persons worldwide and causing four- to five-fold elevated levels of serum LDL-C (5). Despite the availability of multiple lipid-lowering therapies most HoFH patients do not achieve sufficiently low LDL-C levels, and accordingly are at high risk of symptomatic atherosclerotic cardiovascular disease already in childhood (6). In fact, there have been several case reports of sudden cardiac death due to fatal myocardial infarction in children with HoFH before the age of 10 years (7). Of note, the majority of the clinical studies performed on FH patients have included only the much more common form of FH, i.e., HeFH. Accordingly, when we refer to mere “FH,” we refer to studies with HeFH patients, unless specified otherwise.