ApoB test may better guide cholesterol treatment, study finds
Northwestern researchers say apoB testing could prevent more heart attacks and strokes than standard LDL-based decisions while remaining cost-effective.
By Tom Brennan · Health & Medicine Correspondent
3 min read
A blood test that counts harmful cholesterol-carrying particles may help doctors prevent more heart attacks and strokes than standard LDL testing, according to a Northwestern Medicine study published in JAMA. Northwestern said the finding matters because millions of Americans each year rely on LDL, often called “bad” cholesterol, to help assess heart disease risk.
The study found that apolipoprotein B, known as apoB, performed better than LDL cholesterol and non-HDL cholesterol for deciding when to intensify cholesterol-lowering therapy, according to Northwestern. Those treatments included stronger statin therapy and, when needed, adding ezetimibe, the researchers reported.
Ciaran Kohli-Lynch, the study’s lead author and an assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine, said the analysis found apoB-guided treatment would avert more cardiovascular events and offer good value for U.S. health care payers. Northwestern said Kohli-Lynch described the work as the first comprehensive analysis showing apoB-guided cholesterol treatment can be cost-effective.
Why apoB differs from standard cholesterol tests
Doctors commonly use LDL cholesterol and non-HDL cholesterol to decide whether patients should start or increase cholesterol-lowering medication, according to Northwestern. The researchers said those measures are useful but may not fully reflect a patient’s cardiovascular risk.
ApoB measures the number of harmful cholesterol particles in the blood, Northwestern said. The researchers said those particles can lodge in artery walls and contribute to plaque buildup, which can restrict blood flow and raise the risk of heart attack and stroke.
Northwestern said apoB is not yet widely used in routine care. Kohli-Lynch said one barrier is that apoB usually requires an additional blood test beyond the standard cholesterol panel, adding cost and inconvenience.
How the study compared testing strategies
To test whether that extra step was worthwhile, the researchers built a computer model of 250,000 U.S. adults who were eligible for statin therapy and did not already have cardiovascular disease, according to Northwestern. The model compared treatment decisions guided by LDL cholesterol, non-HDL cholesterol and apoB.
The targets in the model were LDL cholesterol below 100 mg/dL, non-HDL cholesterol below 118 mg/dL and apoB below 78.7 mg/dL, according to the study summary. When patients remained above the target, treatment was increased first with stronger statins and then with ezetimibe if needed, Northwestern said.
The researchers projected outcomes over a lifetime, including heart attacks, strokes, life expectancy, quality of life and health care costs, according to Northwestern. ApoB-guided treatment produced better health outcomes than the LDL and non-HDL strategies and remained cost-effective in the model, the university said.
The findings come after the American Heart Association and 10 other medical organizations released updated guidelines this year recommending cholesterol-lowering treatment for many people at younger ages, according to Northwestern. Kohli-Lynch said that shift increases the need to identify who is most likely to benefit from more intensive treatment.
The JAMA study, “Cost-Effectiveness of ApoB, Non-HDL-C, and LDL-C Goals for Primary Prevention Lipid-Lowering Therapy,” was authored by Samuel Luebbe, Allan D. Sniderman, Andrew E. Moran, John T. Wilkins and Ciaran N. Kohli-Lynch. Northwestern said the work was supported by an American Heart Association Career Development Award.
This story draws on original reporting from ScienceDaily.