Millions of Americans undergo blood tests each year to measure LDL cholesterol, also known as “bad” cholesterol. But a new study from Northwestern Medicine suggests that another test may work better at identifying patients who need more aggressive treatment to reduce their risk of heart attack and stroke.
This study Japan Automobile Manufacturers Associationfound that measuring apolipoprotein B (apoB) was more effective than tracking LDL or non-HDL cholesterol in deciding whether to intensify cholesterol-lowering therapy, including statins and other medications.
“We found that apoB testing to enhance cholesterol-lowering drugs can prevent more heart attacks and strokes than current practice, and that these health benefits are achieved at a cost that represents good value for U.S. health care payers,” said study lead author Ciaran Cory-Lynch, assistant professor of preventive medicine in the division of epidemiology at Northwestern University Feinberg School of Medicine.
Cory-Lynch said this is the first comprehensive analysis to show that using apoB to guide cholesterol treatment is also cost-effective.
Heart disease remains the leading cause of death in the United States and causes significant medical costs. Over time, small cholesterol-carrying particles can become trapped within artery walls, where they accumulate in plaques that restrict blood flow and increase the risk of heart attack and stroke.
Why ApoB may be a better measure of heart disease risk
Physicians have long relied on LDL and non-HDL cholesterol levels to determine when a patient should begin or intensify cholesterol-lowering therapy. Although these tests provide useful information, they do not provide a complete picture of a person’s cardiovascular risk.
“Studies strongly suggest that apolipoprotein B (apoB) is good at identifying who is at risk because it counts the total number of harmful particles in the blood,” Coley-Lynch explained.
Unlike standard cholesterol tests, apoB measures the number of cholesterol-carrying particles that can contribute to plaque buildup. Researchers say this is a more direct indicator of cardiovascular risk.
Despite increasing evidence supporting apoB, this test remains not commonly used in daily practice. One reason for this, Cory-Lynch said, is that measuring apoB typically requires additional blood tests beyond a standard cholesterol panel, increasing both cost and inconvenience.
“Our study asked whether it is worth spending the additional money to use apoB instead of LDL to guide treatment intensification,” said Kawli-Lynch.
Computer Model Comparison of Three Cholesterol Testing Strategies
To answer this question, the researchers created a computer simulation representing 250,000 U.S. adults who would be eligible for statin therapy but did not already have cardiovascular disease.
This model compared three approaches to guiding treatment.
- LDL cholesterol (target <100 mg/dL)
- Non-HDL cholesterol (target <118 mg/dL)
- ApoB (target <78.7 mg/dL)
If patients did not meet their goals, treatment was intensified by first using a strong statin and then adding ezetimibe if needed.
The researchers estimated heart attacks, strokes, life expectancy, quality of life, and health care costs following each strategy over a lifetime.
The results showed that using apoB to guide treatment consistently performed better than LDL and non-HDL approaches. It improved overall health and prevented further cardiovascular events in a way that researchers determined was cost-effective.
New cholesterol guidelines raise the importance of accurate testing
The study results come as doctors have access to more cholesterol-lowering drugs than ever before. Earlier this year, the American Heart Association and 10 other medical organizations also released updated guidelines recommending that most people start cholesterol-lowering therapy at a younger age.
“This means it is increasingly important to identify precisely who will benefit most from intensive care,” said Cory-Lynch.
Other Northwestern co-authors include Drs. John Wickins and Samuel Lubbe.
This study, entitled “Cost-effectiveness of ApoB, Non-HDL-C, and LDL-C targets in primary prevention lipid-lowering therapy,” was supported by American Heart Association Career Development Award 24CDA1274989 (Dr. Kohli-Lynch).
