Very-Low-Density Lipoprotein–Associated Apolipoproteins Predict Cardiovascular Events and Are Lowered by Inhibition of APOC-III

BACKGROUND Routine apolipoprotein (apo) measurements for cardiovascular disease (CVD) are restricted to apoA-I and apoB. Here, the authors measured an unprecedented range of apolipoproteins in a prospective, population-based study and relate their plasma levels to risk of CVD. OBJECTIVES This study sought to measure apolipoproteins directly by mass spectrometry and compare their associations with incident CVD and to obtain a system-level understanding of the correlations of apolipoproteins with the plasma lipidome and proteome. METHODS Associations of 13 apolipoproteins, 135 lipid species, and 211 other plasma proteins with incident CVD (91 events), defined as stroke, myocardial infarction, or sudden cardiac death, were assessed prospectively over a 10-year period in the Bruneck Study (N = 688) using multiple-reaction monitoring mass spectrometry. Changes in apolipoprotein and lipid levels following treatment with volanesorsen, a second-generation antisense drug targeting apoC-III, were determined in 2 human intervention trials, one of which was randomized. RESULTS The apolipoproteins most significantly associated with incident CVD were apoC-II (hazard ratio per 1 SD [HR/SD]: 1.40; 95% confidence interval [CI]: 1.17 to 1.67), apoC-III (HR/SD: 1.38; 95% CI: 1.17 to 1.63), and apoE (HR/SD: 1.31; 95% CI: 1.13 to 1.52). Associations were independent of high-density lipoprotein (HDL) and non-HDL cholesterol, and extended to stroke and myocardial infarction. Lipidomic and proteomic profiles implicated these 3 very-low-density lipoprotein (VLDL)-associated apolipoproteins in de novo lipogenesis, glucose metabolism, complement activation, blood coagulation, and inflammation. Notably, apoC-II/apoC-III/apoE correlated with a pattern of lipid species previously linked to CVD risk. ApoC-III inhibition by volanesorsen reduced plasma levels of apoC-II, apoC-III, triacylglycerols, and diacylglycerols, and increased apoA-I, apoA-II, and apoM (all p < 0.05 vs. placebo) without affecting apoB-100 (p = 0.73). CONCLUSIONS The strong associations of VLDL-associated apolipoproteins with incident CVD in the general community support the concept of targeting triacylglycerol-rich lipoproteins to reduce risk of CVD.