Lipoprotein(a) and mortality—a high risk relationship

Lipoprotein(a) (Lp(a)) is an independent cardiovascular risk factor playing a causal role for atherosclerotic cardiovascular disease (ASCVD). Early or progressive ASCVD or a familial predisposition are key findings which can be associated with Lp(a)-hyperlipoproteinemia (Lp(a)-HLP). The German guideline for the indication of lipoprotein apheresis in patients with Lp(a)-HLP has proved to be of value to identify patients at highest risk, using the composite of a Lp(a) threshold >60 mg/dl (>120 nmol/l) and clinical ASCVD progression despite effective LDL-C lowering therapy. In particular for such patients it appears to be plausible that Lp(a)-associated risk would increase cardiovascular mortality as the most important part of total mortality in Western populations. By the majority of existing investigations an association of Lp(a) concentration on total or cardiovascular mortality was demonstrated. However, inconsistency in the findings between studies exists without a clear trend for any study feature to explain this. Genetic homogeneity of the population, long-term follow-up, and clinically guided selection of patients might be important to further clarify the impact of Lp(a) concentration on progression of ASCVD, and finally total or cardiovascular mortality. LDL and Lp(a) particles exhibit a mutual effect modification on related ASCVD risk. Therefore, LDL-C levels and concomitant LDL-C lowering treatment must be considered in this context. Prospective evaluation is needed to document that specific Lp(a)-lowering additional to targeted LDL-C lowering will in fact reduce cardiovascular or total mortality.