Lipoprotein(a): current perspectives

Recent data from genetic and epidemiological studies strongly support a causal relationship between elevated lipoprotein(a) [Lp(a)] concentrations and the development of atherosclerosis and cardiovascular disease. This relationship is continuous, without an Lp(a) threshold, and it is independent of low density lipoprotein and high density lipoprotein cholesterol (LDL-C and HDL-C, respectively) levels. Although the mechanism(s) through which Lp(a) promotes atherosclerosis are not clearly understood, proposed mechanisms include an increased Lp(a)-associated cholesterol entrapment in the arterial intima, inflammatory cell recruitment, carrying of proinflammatory oxidized phospholipids, impairing fibrinolysis by inhibition of plasminogen activation and enhancing coagulation by inhibition of the tissue factor pathway inhibitor. Phenotypically there are two forms, isolated hyperlipoproteinemia(a) in the presence of normal LDL-C, and combined elevations of Lp(a) and LDL-C. There are no drugs or other therapeutic options available that selectively decrease Lp(a). Those that can lower Lp(a) levels only have a moderate effect and their actions include decreasing LDL-C levels. The strongest effects are seen with niacin at high doses. Nevertheless, there is no convincing evidence that decreasing isolated elevations of Lp(a) offers cardiovascular benefit. This review considers the evidence supporting the association between Lp(a) and atherosclerotic disease, discusses the potential mechanisms involved in the pro-atherosclerotic potential of Lp(a), and evaluates the therapeutic options that decrease elevated Lp(a) levels.