“Biomarkers could be used both for predicting disease risk and for selecting those who would potentially bene t most from therapy.”
Biomarkers could give your doctor a window into your heart risks, so you can start making changes to reverse them.
What if a single blood test could tell you that a heart attack was in your future? Medicine isn’t quite at that point yet, but there are a few indicators—substances your doctor can look for in your blood, as well as in your urine and tissues—that can signal where your cardiovascular health is headed and let you know whether you need to take action now to prevent a heart attack or stroke.
These substances are called biomarkers, and they reflect processes that are going on inside your body, says Dr. Samia Mora, assistant professor of medicine at Harvard Medical School and associate physician at Brigham and Women’s Hospital. “Biomarkers could be used both for predicting disease risk and for selecting those who would potentially benefit most from therapy,” she says.
Many biomarkers—including total cholesterol, HDL (good) cholesterol, and LDL (bad) cholesterol—are part of the assessment your doctor uses to determine your heart disease risk, “But sometimes we don’t think of them as biomarkers, because they’re so much a part of our understanding of disease,” Dr. Mora says.
State of the heart
Over the last decade or so, researchers have been trying to home in on other biomarkers that can help them fine-tune heart disease prediction. For a marker to be an effective predictive tool, it must be accurate and easy to measure, and carry minimal risks (such as radiation exposure). A useful biomarker also needs to provide doctors with new information beyond what other tests already offer, Dr. Mora says.
These are a few biomarkers that researchers are currently studying for heart disease:
C-reactive protein (CRP) is a marker of inflammation in the body. Inflammation has been linked to heart disease, as well as to other conditions. 2010 guidelines from the American Heart Association and American College of Cardiology (AHA/ACC) recommend measuring CRP levels in women ages 60 or older who, based on their risk factors, have a low or moderately elevated risk of cardiovascular events, to determine whether they need cholesterol-lowering statin therapy.
Apolipoproteins are a kind of protein found in cholesterol. ApoA1 is in HDL cholesterol, while ApoB is in LDL cholesterol. In general, measuring apolipoproteins hasn’t shown any improvement over standard cholesterol measures for assessing heart disease risks.
Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme released by inflammatory cells. It’s thought to play a role in atherosclerosis—the plaque buildup in arteries that can lead to heart attack and stroke. Studies suggest that measuring Lp-PLA2 can help doctors predict both heart disease and stroke.
B-type natriuretic peptide (BNP) is a hormone that’s produced in response to excess stress on the heart. BNP is already used to diagnose heart failure, and studies have found that high BNP levels can also indicate risk for heart attack, stroke, and death from heart disease.
Cardiac troponin measures proteins released into the blood during a heart attack. It has become the gold standard for diagnosing a heart attack. Measuring the level of troponins circulating in the blood may also help diagnose heart disease—particularly in women with type 2 diabetes.
Many of the processes and risks these biomarkers identify are the same in men and women. However, because women naturally have different levels of certain biomarkers—such as CRP, BNP, and troponin—the tests used to measure these biomarkers may need to be interpreted differently or have separate thresholds for men and women.
One single biomarker may not be able to tell you whether a heart attack is imminent, but a group of biomarkers evaluated together could give your doctor valuable insight into your cardiovascular future. Which specific biomarkers would be worthwhile to include in that panel is still being investigated.
Learning your risks now
For now, the best way to assess your future heart disease risk is to use a tool like the AHA/ACC Risk Estimator, which is available online (tools.cardiosource.org/ASCVD-Risk-Estimator/). Plug in details like your gender, age, HDL and total cholesterol, systolic blood pressure (the top number), and whether you smoke. The tool will give you an estimate of your 10-year risk for a heart attack, stroke, or death from heart disease.
This estimator can help you learn whether you are at high, medium, or low risk for heart disease. Discuss all of your heart disease risks, and how to modify them, with your doctor. “Approximately 80% to 90% of cardiovascular disease cases can be prevented by lifestyle modification alone—eating a healthy diet, exercising, keeping body weight in a healthy range, not smoking, and making sure blood pressure and cholesterol are in reasonable ranges,” Dr. Mora says. “The earlier you can address these risk factors, the better.”