Lipoprotein(a), or Lp(a), is a sticky, LDL-like cholesterol particle that circulates in the blood and contributes to plaque buildup in arteries, increasing the risk of heart attack and stroke. Unlike standard LDL cholesterol, Lp(a) levels are largely determined by genetics and remain relatively constant throughout life, making lifestyle changes less effective at lowering them.
Approximately one in five people worldwide have elevated Lp(a) levels, yet most are unaware because it is not included in typical cholesterol panels. A 2023 study published in the Journal of the American College of Cardiology found that individuals with high Lp(a) face up to a 60% increased risk of cardiovascular events compared to those with normal levels.
Lp(a) is a causal risk factor for atherosclerosis and aortic stenosis, said Dr. Samia Mora, a cardiologist at Brigham and Women’s Hospital and professor at Harvard Medical School. Because it’s inherited, we often see patterns of early heart disease in families that standard cholesterol tests miss.
Testing for Lp(a) involves a simple blood test, but it is not routinely ordered unless there is a personal or family history of premature cardiovascular disease. Experts recommend screening for individuals with a first-degree relative who had a heart attack or stroke before age 55 in men or 65 in women, or those with recurrent cardiovascular events despite statin therapy.
While no approved drugs currently target Lp(a) specifically, several investigational therapies, including antisense oligonucleotides and small interfering RNA treatments, are in late-stage clinical trials and show promise in reducing Lp(a) by up to 80%. In the meantime, managing other risk factors — such as LDL cholesterol, blood pressure, and smoking — remains critical.
For decades, heart disease prevention has focused on LDL cholesterol, but experts say it’s time to broaden the lens. We need to stop treating cholesterol as a single number, added Dr. Mora. Lp(a) is a silent threat hiding in plain sight, and identifying it early can change outcomes.
Understanding Lipoprotein(a) and Heart Health
Lp(a) resembles LDL cholesterol but contains an additional protein called apolipoprotein(a), which makes it more likely to promote clotting and inflammation in arterial walls. This dual action accelerates atherosclerosis and increases the likelihood of calcific aortic valve stenosis, a narrowing of the heart’s aortic valve.
Because Lp(a) is genetically encoded, levels are set at birth and are not significantly altered by diet or exercise. However, knowing your Lp(a) status allows for earlier intervention, including more aggressive LDL lowering and consideration of emerging therapies when available.
Key questions
- What is lipoprotein(a) and why is it dangerous?
- Lipoprotein(a), or Lp(a), is a genetically determined cholesterol particle that contributes to artery plaque buildup and blood clotting. It increases the risk of heart attack, stroke, and aortic valve stenosis, and is not affected by diet or exercise, making it a hidden but significant cardiovascular risk factor.
- Who should get tested for high Lp(a) levels?
- Individuals with a family history of premature heart disease — such as a heart attack or stroke in a male relative before 55 or female relative before 65 — should consider Lp(a) testing. It is also recommended for those with recurrent cardiovascular events despite statin therapy or elevated LDL cholesterol.
