Differenzierung der Indikation zur Lipoproteinapherese bei erhöhtem Lp(a) durch unterschiedliche Messmethoden

Lipoprotein(a) - Marker for cardiovascular risk and target for lipoprotein apheresis

Lipoprotein(a) (Lp(a)) consists of an LDL particle whose apolipoprotein B (apoB) is covalently bound to apolipoprotein(a) (apo[a]). An increased Lp(a) concentration is a causal, independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and a predictor of incident or recurrent cardiovascular events. Although Lp(a) was first described as early as 1963, only the more recent results of epidemiological, molecular, and genetic studies have led to this unequivocal conclusion. More than 20% of Western populations have elevated Lp(a) values. Lp(a) concentrations should be always part of the lipid profile when ASCVD risk is assessed. However, presence of other risk factors, laboratory findings, medical history and family history must be considered to conclude on its clinical relevance in an individual patient. Early or progressive ASCVD or a familial predisposition are key findings which can be associated with elevated Lp(a). The cholesterol portion contained in Lp(a) is also included in the various methods of LDL-C measurement. To assess proximity to the cardiovascular risk related target value for LDL-C, appropriate correction should be applied when high Lp(a) values are obtained to estimate the LDL-C that can actually be treated by lipid lowering drugs. Initial study data show that antisense oligonucleotides, which selectively decrease apolipoprotein(a), are promising as future treatment options. Currently, lipoprotein apheresis, which has a reimbursement guideline in Germany, is the therapy of choice for patients with Lp(a)-associated progressive ASCVD, with the aim of sustained prevention of further cardiovascular events.

Current insights into the German lipoprotein apheresis standard: PCSK9-inhibitors, lipoprotein apheresis or both?

According to current European guidelines, lipid lowering therapy for progressive cardiovascular disease including cardiovascular events has to be focused on a target level for LDL-C. In contrast for Lp(a) a threshold has to be defined with respect to the method of measurement. However, due to new lipid lowering drug developments like PCSK9-inhibitors (PCSK-9-I) a therapeutic algorithm for patients with severe hypercholesterolemia or isolated Lipoprotein(a)-hyperlipoproteinemia with progressive cardiovascular disease may be necessary to manage the use of PCSK9-I, lipoprotein apheresis (LA) or both. The therapeutic approach for patients with homozygous familial hypercholesterolemia is unambiguous: In addition to LA, in order to improve LDL-C reduction, PCSK9-I could be applied. In patients with heterozygous familial hypercholesterolemia, PCSK9-I is to be applied first. If in addition to a pronounced LDL-C elevation, cardiovascular complications exist or if imaging techniques documented atherosclerotic changes pre-disposing for a cardiovascular event while LDL-C reduction is insufficiently reduced (LDL-C > 100 mg/dl (2.6 mmol/l)), LA treatment should then be applied as last resort. In patients with elevated Lp(a) concentrations (Lp(a) > 60 mg/dl (>120 nmol/l)) and established cardiovascular disease, therapy should rely primarily on LA methods. If in addition to high Lp(a) levels insufficiently treated LDL-C concentrations (LDL-C > 100 mg/dl (2.6 mmol/l)) exist, in rare cases PCSK9-I can supplement the lipid lowering concept.