Coronary artery event-free or resilient familial hypercholesterolemia: what's in a name?

Abstract

Familial hypercholesterolemia (FH) is an autosomal semi-dominant condition, characterized by excessive circulating low-density lipoprotein cholesterol (LDL-C) from birth that substantially accelerates the onset and progression of atherosclerotic cardiovascular disease (ASCVD), classically coronary artery disease (CAD). Elevated plasma LDL-C integrated over time is unequivocally the major determinant of ASCVD in heterozygous FH (HeFH); however, the wide variation in incidence and progression of ASCVD suggests a role for a wide spectrum of risk modifiers. We reviewed recent evidence describing the features of an ASCVD-free entity referred to as resilient FH among patients with HeFH. Compared with nonresilient FH patients, resilient patients are more likely to be female, and have a lower prevalence of ASCVD comorbidities, higher levels of HDL-C and larger HDL particles, as well as a lower level of lipoprotein(a). A lower SAFEHEART risk score is also an independent predictor of resilient FH. Gene expression studies also demonstrate that resilient FH patients are associated with a less atherogenic gene expression profile in relation to HDL metabolism and immune responses, as reflected by higher expression of ABCA1 and ABCG1, and lower expression of STAT2 and STAT3, respectively. A group of HeFH patients, referred as resilient FH, can survive to advance ages without experiencing any ASCVD events. Several key contributors to the event-fee CAD in HeFH patients have been identified. This could not only improve risk stratification and management for FH but also be of major importance for the general population in primary and secondary prevention. However, resilient FH remains an under-investigated area and requires further research.