Scientists looked at blood samples from more than 20,000 people who were part of three big NIH trials. They wanted to see how a blood protein called Lipoprotein(a), or Lp(a), affects the heart.
Lp(a) is a tiny particle that carries cholesterol. It looks like the “bad” LDL cholesterol but carries an extra protein that can make it more dangerous.
About one out of five adults has a high Lp(a) level. Most don’t know it because it usually shows no symptoms. The amount a person has is mostly decided by their genes.
The researchers split the participants into four groups based on their Lp(a) numbers: less than 75, 75‑124, 125‑174, and 175 or higher. They also noted whether each person already had heart disease.
During almost four years of follow‑up, 1,461 people (7.3%) suffered a major heart event such as a heart attack, stroke, a procedure to open blocked arteries, or died from a heart problem.
People with Lp(a) levels of 175 nmol/L or more faced a higher chance of these events. Their risk of a serious heart problem was about 31% higher, the risk of dying from heart disease rose 49%, and the risk of stroke went up 64% compared with those who had lower levels.
The link was strongest in participants who already had heart disease. Having a very high Lp(a) did not raise the risk of a heart attack in this study.
The good news is that a simple, cheap blood test can tell if you carry this hidden risk. If the test shows a high Lp(a), doctors recommend lowering LDL cholesterol aggressively and controlling other risk factors like blood pressure and smoking.
New medicines that target Lp(a) are being studied, so knowing your level now could help you benefit from future treatments.
Researchers also plan to examine other groups, such as people with kidney disease or poor blood flow in the legs, to see how Lp(a) influences their health.