High-density lipoprotein cholesterol (HDL-C) levels have historically been inversely associated with increased cardiovascular disease (CVD) risk.
1 However, recent studies have questioned the efficacy of therapies designed to increase HDL-C levels. For example, cholesteryl ester transfer protein inhibition that increases HDL-C levels does not reduce CVD risk.
2-7 Additionally, genetic variants associated with HDL-C are not linked to CVD risk.
8 Recent epidemiologic studies in populations free of CVD from northern Europe and Canada have linked very high levels of HDL-C with higher mortality risk.
9,10 Whether very high HDL-C levels in patients with coronary artery disease (CAD) are associated with mortality risk remains unknown. We investigated the association between very high HDL-C levels and all-cause and cardiovascular mortality risk in 2 independent groups of patients with CAD in the UK Biobank (UKB) and the Emory Cardiovascular Biobank (EmCAB) and the association of known HDL-C genetic variants with this risk. Our hypothesis was that very high HDL-C would be associated with greater mortality risk in individuals with CAD, and there may be a genetic association with this risk.