Lp(a): The Genetic Cardiovascular Risk Factor Most People Have Never Heard Of
Lipoprotein(a), or Lp(a), is an LDL-like particle with an extra protein, apolipoprotein(a), attached. Its level is set almost entirely by genes, and genetic and population studies strongly support it as a cause of cardiovascular disease, even when LDL cholesterol is very low.6 A 2022 European expert consensus recommends measuring it at least once in adulthood.6
- Lp(a) has pro-inflammatory and pro-atherosclerotic properties, which may partly come from the oxidized phospholipids it carries; current findings do not support it as a risk factor for blood clots in the veins.6
- In a family study, the apo(a) gene accounted for 91% of the variation in Lp(a) levels, and statins tend to raise Lp(a) rather than lower it.3,2
- In a large genetic study, two common variants in the LPA gene raised Lp(a) and increased the odds of coronary disease by 70% and 92%.1
- Until Lp(a)-specific treatments are proven, experts recommend early, intensive management of overall cardiovascular risk, and the 2026 US guideline recommends measuring Lp(a) at least once in adulthood, counting 125 nmol/L (50 mg/dL) or more as a risk-enhancing factor.6,9
- An RNA-based drug, pelacarsen, lowered Lp(a) by up to 80% in a 2020 phase 2 trial,5 but in September 2026 its phase 3 outcome trial reported that it did not reduce heart attacks, strokes or cardiovascular deaths. Trials of other Lp(a)-lowering drugs were still in progress as of October 2026.7
Lipoprotein(a) was first described in 1963. For decades it was linked to heart disease in observational studies without clear evidence that it caused that risk. A 2009 genetic study found that two variants at the LPA gene were strongly associated with both higher Lp(a) and coronary disease.1 By 2022, a European consensus concluded that epidemiologic and genetic studies involving hundreds of thousands of people strongly support a causal, continuous association between Lp(a) and cardiovascular outcomes.6
What Makes Lp(a) Uniquely Dangerous
Lp(a) is an LDL-like particle with apolipoprotein(a) attached. Apolipoprotein(a) is structurally similar to plasminogen, the precursor of a clot-dissolving enzyme,7 which led to the idea that Lp(a) promotes clotting. However, the 2022 European consensus found that current evidence does not support Lp(a) as a risk factor for venous blood clots or impaired clot breakdown; its harm appears to come from its pro-atherosclerotic and pro-inflammatory properties, which may partly relate to the oxidized phospholipids it carries.6
Elevated Lp(a) is also a risk factor for calcific aortic valve stenosis and is associated with calcification of the aortic valve.2,6 It adds risk even in people whose LDL cholesterol is below 70 mg/dL, so LDL-focused treatment alone does not remove it.2,6
The Genetic Architecture: Why Lifestyle Does Not Change It
Lp(a) levels are set mainly by the LPA gene, which encodes apolipoprotein(a). In a study of 48 families, the gene accounted for 91% of the variation in Lp(a) levels, and the number of kringle 4 repeats in the gene, which is inversely related to Lp(a) concentration, accounted for 69%.3
Standard treatments do little: statins tend to increase Lp(a), PCSK9 inhibitors lower it by 20% to 30%, and RNA-targeted therapies in development lower it by more than 80%.2 Because levels are genetically set, the 2022 consensus recommends testing at least once in adulthood rather than repeatedly.6
What to Do With an Elevated Lp(a)
Without specific Lp(a)-lowering therapies, the 2022 European consensus recommends early, intensive management of overall cardiovascular risk, tailored to both global risk and Lp(a) level.6 In the US, the 2026 dyslipidemia guideline, which replaced the 2018 cholesterol guideline,8,4 recommends measuring Lp(a) at least once in adulthood and counts 125 nmol/L (50 mg/dL) or more as a risk-enhancing factor.9
Lp(a)-Lowering Drugs: The First Outcome Result
In a 2020 phase 2 trial of 286 people with cardiovascular disease and high Lp(a), the antisense drug AKCEA-APO(a)-LRx, now called pelacarsen, lowered Lp(a) in a dose-dependent way, by 35% at the lowest dose and 80% at the highest.5 A 2026 review described several RNA-based drugs that lower Lp(a) by up to 80% to 90%.7
The first outcome result was a disappointment. On September 4, 2026, the companies developing pelacarsen announced that Lp(a)HORIZON, a phase 3 trial in 8,323 people with established cardiovascular disease and high Lp(a), did not meet its primary goal: despite substantially lower Lp(a) levels, pelacarsen did not significantly reduce the combination of cardiovascular death, heart attack, stroke and urgent hospital procedures to restore blood flow to the heart (Ionis/Novartis, September 2026). As of October 2026 the full results had not been presented, and outcome trials of other Lp(a)-lowering drugs were still in progress. Whether lowering Lp(a) prevents cardiovascular events is now an open question, which is one more reason the current advice for people with high Lp(a) focuses on controlling every other risk factor, especially LDL cholesterol and blood pressure.
Put this research into practice: Gene Variant Lookup · Biomarker Reference Tool · What Should I Test Next?
References
- 1Clarke R, et al. "Genetic variants associated with Lp(a) lipoprotein level and coronary disease." N Engl J Med. 2009;361(26):2518-28. PubMed · DOI
- 2Tsimikas S. "A Test in Context: Lipoprotein(a): Diagnosis, Prognosis, Controversies, and Emerging Therapies." J Am Coll Cardiol. 2017;69(6):692-711. PubMed · DOI
- 3Boerwinkle E, et al. "Apolipoprotein(a) gene accounts for greater than 90% of the variation in plasma lipoprotein(a) concentrations." J Clin Invest. 1992;90(1):52-60. PubMed · DOI
- 4Grundy SM, et al. "2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines." Circulation. 2019;139(25):e1082-e1143. PubMed · DOI
- 5Tsimikas S, et al. "Lipoprotein(a) Reduction in Persons with Cardiovascular Disease." N Engl J Med. 2020;382(3):244-255. PubMed · DOI
- 6Kronenberg F, et al. "Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement." Eur Heart J. 2022;43(39):3925-3946. PubMed · DOI
- 7Granata LG, et al. "Lipoprotein(a) in cardiovascular disease: pathophysiology, residual risk, and emerging therapeutic strategies." Front Med (Lausanne). 2026;13:1886347. PubMed · DOI
- 8Blumenthal RS, et al. "2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines." Circulation. 2026;153(17):e1154-e1276. PubMed · DOI
- 9Sabouret P, et al. "The 2026 ACC/AHA Dyslipidemia Guideline: A Critical and Transatlantic Perspective on Personalized Lipid Management." Life (Basel). 2026;16(9). PubMed · DOI
