Every year, millions of Americans dutifully roll up their sleeves for a blood test to measure LDL, the so-called “bad” cholesterol. But new research from Northwestern Medicine suggests that another test might be better at identifying who actually needs to panic about heart attacks and strokes.

The study, published in JAMA, found that measuring apolipoprotein B (apoB) was more effective than tracking LDL or non-HDL cholesterol when deciding whether to intensify cholesterol-lowering therapy - including statins and other medications. “We found that apoB testing to intensify cholesterol-lowering medication would prevent more heart attacks and strokes than current practice, and that these health benefits were achieved at a cost that represents good value for U.S. healthcare payers,” said lead author Ciaran Kohli-Lynch, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine.

Heart disease remains the leading cause of death in the United States, because tiny cholesterol-carrying particles have a nasty habit of getting trapped in artery walls and forming plaques that restrict blood flow. Doctors have long relied on LDL and non-HDL cholesterol levels, but those tests don’t fully capture risk. ApoB, on the other hand, counts the total number of harmful particles - making it a more direct indicator of who’s in trouble.

The catch? ApoB generally requires an additional blood test, which means more cost and inconvenience. So the research team created a computer simulation of 250,000 U.S. adults eligible for statins but without existing cardiovascular disease, comparing three treatment strategies: one guided by apoB targets, one by non-HDL targets, and one by LDL targets. The result? ApoB consistently outperformed the others, preventing more cardiovascular events and proving cost-effective over a lifetime.

The findings arrive just as doctors have more cholesterol-lowering drugs than ever, and the American Heart Association recently updated guidelines to recommend starting therapy at younger ages. “This means it is increasingly important to accurately identify who would benefit most from intensive treatment,” Kohli-Lynch said. So maybe it’s time to ask your doctor for the apoB test - before your arteries throw a plaque party.