Purpose of review: To review the recent evidence from observational/genetic/interventional studies addressing triglycerides and residual cardiovascular risk (CVRisk).
Recent findings: Large population-based and secondary prevention studies consistently show an association of higher triglycerides with increased CVRisk. This is compounded by genetic studies demonstrating an independent relationship between triglyceride raising or lowering genetic variants affecting triglyceride-rich lipoproteins (TRL) metabolism and CVRisk. Mendelian randomization analysis suggests the benefit of genetic lowering of triglycerides and LDL-cholesterol is similar per unit change in apolipoprotein-B. Among cholesterol-lowering trials, more intensive statin therapy produced greater CVRisk reductions in patients with higher TRL-cholesterol or triglycerides; proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition led to similar triglycerides reduction but greater non-HDL-C or apolipoprotein-B reductions than fibrates or fish oils. Regarding n-3 fatty acids, A Study of Cardiovascular Events in Diabetes (ASCEND) and Vitamin D and Omega-3 Trial (VITAL) primary prevention trials with eicosapentaenoic acid (EPA) and docosahexaenoic acid failed to demonstrate cardiovascular benefits, Conversely, Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) using high-dose icosapent-ethyl (purified EPA) in primary (diabetes) and secondary prevention with hypertriglyceridemia showed significant cardiovascular events reductions (greater than expected by the observed triglycerides or apolipoprotein-B reductions, suggesting potential benefits through non-lipid pathways).
Summary: Evidence suggests higher triglycerides are a marker of CVRisk and may help identify patients who benefit from intensification of therapy. Moreover, genetic studies support a causal link between TRL/triglycerides and cardiovascular disease. Treatment with high-dose EPA may be of benefit in high-risk patients with hypertriglyceridemia to reduce CVRisk.