Heart disease is the leading cause of death in the United States, causing more deaths than any other illness and costing the healthcare system a lot of money. This disease develops silently but can be very harmful. When cholesterol particles build up inside artery walls, they form thick deposits. These blockages narrow the blood vessels, increasing the chance of a sudden heart attack or a serious stroke.
For many years, doctors have used a common test to measure this risk. They check low-density lipoprotein, known as "bad cholesterol." This test measures the total amount of cholesterol in the particles circulating in a patient's blood.
However, a different measurement might be more important for saving lives. A study from 2026, published in the Journal of the American Medical Association, found that a blood test that is not used often is much better at guiding treatment than the usual test.
This alternative test measures apolipoprotein B, or apoB. This protein is found on the surface of all the dangerous particles in the blood that can form blockages. While the standard test measures the weight of cholesterol, the apoB test counts the number of these harmful particles.
"Research strongly suggests that apolipoprotein B (apoB) is better at identifying who is at risk because it counts the total number of harmful particles in the blood," said Ciaran Kohli-Lynch, an assistant professor at Northwestern University Feinberg School of Medicine, who led the study. The research team created a computer model of 250,000 Americans to understand the test's impact. They focused on people who could benefit from cholesterol-lowering drugs but had not yet had a major heart problem.
The simulation followed these virtual patients throughout their lives, tracking outcomes like heart attacks, strokes, and medical costs. They compared three strategies: one focused on lowering bad cholesterol, another on non-HDL cholesterol, and the third on keeping apoB levels low.
The results showed that the apoB-guided strategy prevented more heart problems over a lifetime than the other two methods. The study, supported by the American Heart Association, also found that using apoB testing to manage cholesterol provides good financial value to the U.S. healthcare system.
Despite the evidence, the apoB test is not widely used because it usually requires an extra blood draw, increasing costs and patient inconvenience. However, new guidelines from the American Heart Association and other medical groups recommend starting cholesterol-lowering medications earlier for many people. As more younger patients begin treatment, doctors need the best tools to guide their care. Counting the particles, instead of just weighing them, could be crucial for protecting heart health.