The forgotten lipids: Triglycerides, remnant cholesterol, and atherosclerotic cardiovascular disease risk

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) is a well-established mediator of atherosclerosis and a key target for intervention for the primary and secondary prevention of ASCVD. However, despite substantial reduction in LDL-C, patients continue to have recurrent ASCVD events. Hypertriglyceridemia may be an important contributor of this residual risk. Observational and genetic epidemiological data strongly support a causal role of triglycerides (TGs) and the cholesterol content within triglyceride-rich lipoproteins (TGRLs) and/or remnant cholesterol (RC) in the development of ASCVD. TGRLs are composed of hepatically derived very low-density lipoprotein and intestinally derived chylomicrons. RC is the cholesterol content of all TGRLs and plasma TGs serve as a surrogate measure of TGRLs and RC. Although lifestyle modification remains the cornerstone for management of hypertriglyceridemia, many novel drugs are in development and have shown impressive efficacy in lowering TG levels. Several ongoing, randomized controlled trials are underway to examine the impact of these novel agents on ASCVD outcomes. In this comprehensive review, we provide an overview of the biology, epidemiology, and genetics of TGs and ASCVD; we discuss current and novel TG-lowering therapies under development.