Lp(a) Risk Interpreter.

Lipoprotein(a), pronounced "L-P little a", is an LDL-like particle with an extra protein (apo(a)) attached. It is essentially a more atherogenic, pro-thrombotic, pro-inflammatory cousin of regular LDL. Crucially, your Lp(a) level is ~90% genetically determined — it is set at birth, stays roughly constant through life, and barely responds to diet, exercise, or even most statins.

Despite affecting an estimated 1 in 5 adults globally with clinically elevated values, Lp(a) is still not part of standard cholesterol panels in most countries. The 2022 European Atherosclerosis Society now recommends at least one lifetime measurement for every adult. The 2018 AHA/ACC cholesterol guideline lists elevated Lp(a) as a "risk-enhancing factor" that should tilt borderline statin decisions toward treatment.

Mendelian randomization studies show a causal, dose-dependent relationship between Lp(a) levels and cardiovascular events — including heart attack, stroke, calcific aortic stenosis, and venous thromboembolism. People in the top decile of Lp(a) have roughly 2–3× the lifetime ASCVD risk of those at the population median, independent of LDL, blood pressure, smoking, or diabetes.

Crucially, the standard cardiovascular risk calculators (PCE, PREVENT) do not include Lp(a). So a "low risk" PREVENT score with high Lp(a) is a misleading low number. Always interpret a normal risk-calculator output in the context of your Lp(a).

The 2022 EAS thresholds: low <14 mg/dL (or <30 nmol/L), borderline 14–30 mg/dL, intermediate 30–50 mg/dL, high 50–180 mg/dL, very high ≥180 mg/dL. Units of measurement differ between assays — mg/dL (mass) and nmol/L (particle number) are not interchangeable, and the conversion factor varies by assay because apo(a) particle size varies. Most modern labs report nmol/L; older U.S. labs use mg/dL.

Lp(a) is set at birth and stable for life. One measurement is usually enough — unless the result is in the borderline / intermediate band, in which case a confirmatory re-test is worth doing.

Lp(a) is autosomal codominantly inherited. Each first-degree relative (parent, sibling, child) of someone with elevated Lp(a) has roughly a 50% chance of also being elevated. Cascade family screening — testing siblings and children — is one of the highest-yield preventive interventions you can do.

If your Lp(a) is elevated, get your parents (if alive), siblings, and children tested. The combined family history is much more informative than any one person's number.

Lp(a) itself is largely unresponsive to lifestyle and to most statins (statins can mildly *raise* Lp(a) by ~10%, though the LDL-lowering benefit still nets out positive for cardiovascular outcomes). PCSK9 inhibitors lower Lp(a) by 20–30%. Niacin lowers it ~20% but is no longer recommended due to lack of cardiovascular outcome benefit.

For very high Lp(a) with established disease, lipoprotein apheresis (FDA-approved) reduces Lp(a) by ~70% per session. The bigger story is the pipeline: pelacarsen and olpasiran are Lp(a)-specific antisense / siRNA therapies in Phase 3 trials (HORIZON, OCEAN(a)) that drop Lp(a) by 70–90% per dose. Cardiovascular endpoint data is expected 2026–2028, and if positive, will be the first Lp(a)-targeted disease-modifying therapy.

Until then, the strategy is to be aggressive on the modifiable risk factors that compound with Lp(a): get ApoB / non-HDL well below standard targets (ApoB <80, often <60), tightly control BP, do not smoke, treat diabetes aggressively, and prioritize VO2 max.