Doctors might be using the wrong blood test to assess a person’s risk for clogged arteries, a new study argues.

A routine blood test called apolipoprotein B, or apoB, is better at guiding cholesterol-lowering treatment than other tests that health care professionals use more often, researchers reported April 8 in the Journal of the American Medical Association.

The apoB test outperformed tests that assess “bad” LDL cholesterol levels and other types of harmful cholesterol, researchers found.

“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. health care payers,” lead researcher Ciaran Kohli-Lynch said in a news release. He’s an assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine in Chicago.

Harmful cholesterol contributes to the formation of plaques on the walls of arteries, researchers said in background notes. These plaques choke off blood flow and can contribute to a heart attack or stroke.

The apoB test works by tracking a protein found on particles that can deposit cholesterol in artery walls, according to the American Heart Association.

The test estimates how many particles are carrying harmful cholesterol through the bloodstream; the more particles, the greater a person’s risk for clogged arteries.

For the new study, researchers created a computer model simulating 250,000 U.S. adults eligible for statins but who hadn’t developed heart disease.

With the model, researchers compared strategies using three different cholesterol tests to guide treatment:

• Lowering “bad” LDL cholesterol below 100 mg/dL

• Lowering harmful cholesterol to below 118 mg/dL

• Lowering apoB to less than 78.7 mg/dL

In the simulation, doctors increased medication until people reached their cholesterol goal, then tracked their health outcomes over a lifetime.

Cholesterol care guided by the apoB test outperformed the other two strategies, preventing more heart attacks and strokes, researchers concluded.

The number of cholesterol-lowering medicines available to doctors has vastly expanded over the past decade, researchers noted.

Further, the importance of lowering cholesterol has been emphasized by new guidelines that call for life-long testing and earlier treatment, researchers said.

“This means it is increasingly important to accurately identify who would benefit most from intensive treatment,” Kohli-Lynch said.