Being able to identify which patients are at the highest risk for a heart attack—before life-threatening symptoms strike—has long been “the holy grail” of prevention.
A new blood test could help predict heart attack danger by checking for certain cells that signal impending risk, according to a new study published in Physical Biology.
The test could be a major breakthrough, since the researchers report that, “The ability to identify individuals at the greatest risk of heart attack before its clinical manifestation is considered the most important unmet need in cardiovascular medicine.”
In the study, a new “fluid biopsy” technique successfully distinguished between patients who were being treated for a recent heart attack and those in a healthy control group.
“Our results were so significant relative to the healthy controls that the obvious next step is to assess the usefulness of the test in identifying patients during the early stages of a heart attack,” study coauthor Peter Kuhn said in a statement.
To find out more about the new test and other ways to predict future heart attack risk, I talked to Amy Doneen, ARNP, medical director of the Heart Attack & Stroke Prevention Center in Spokane, Washington.
A Biomarker the May Signal Heart Attack Risk
The fluid biopsy test—known as high-definition circulating endothelial cell assay—looks for endothelial cells circulating in the bloodstream. The endothelium is the protective lining of blood vessels.
“This test is a way to measure endothelial injury and damage,” which occurs when cholesterol plaque builds up inside arterial walls and becomes inflamed, explains Doneen, co-author of Beat the Heart Attack Gene.
If inflamed plaque goes undetected and untreated, it can rupture through the endothelium, much like a volcano erupting, adds Doneen. “In response to this injury, a blood clot can form, blocking blood flow and ultimately leading to a heart attack.”
The researchers report that endothelial cells in the bloodstream are strongly linked to heart attacks and therefore the test might serve as a way to detect an impending heart attack. In the study, levels of these cells were significantly higher in the heart attack patients than in the healthy control group.
The still experimental technique, which is not yet available to medical providers and patients, needs further study to investigate its predictive value in people who have not yet had a heart attack. However, there are existing methods that can also help your medical provider tell if you might be headed for a heart attack.
A Multi-Marker Approach to Predict Heart Attack Danger
Using a combination of simple, widely available blood and urine tests can provide a more accurate assessment of heart attack risk than does the standard cholesterol test alone, according to a 2013 study involving more than 95,000 patients.
In the study, which was published in Future Cardiology, the patients received a panel of lab tests that check for several biomarkers that can warn of future heart attack danger, including high blood sugar, elevated inflammatory markers, and cholesterol abnormalities.
As I reported recently, the multi-marker approach identified 37 to 43 percent more at-risk patients than would have been found using levels of LDL (bad) cholesterol alone, scientists from Cleveland HeartLab and MIVIP found.
This combination approach helped stratify which patients were at highest risk for a heart attack, according to lead study author Marc Penn, MD, PhD, chief medical officer of Cleveland HeartLab.
Earlier research reveals that only checking cholesterol can miss many people who are in danger. For example, a 2009 UCLA study that included more than 136,000 people who were hospitalized with heart attacks reported that nearly 75 percent of them had cholesterol levels didn’t indicate any cardiac risk, and nearly half had “optimal” LDL levels.
How Hot Are Your Arteries?
The screening panel used in the Cleveland HeartLab/MDVIP study consisted of several lab tests that are available separately through medical providers, including Doneen, who uses a “fire panel” of blood and urine tests to check her patients for signs of arterial inflammation, along with ultrasound imaging to look for plaque in artery walls.
“Think of plaque as kindling,” says Doneen. “Inflammation is what lights the match—and can ignite a heart attack if there is plaque in your arteries.” In this study, the three most predictive blood tests to check for heart attack risk were:
- Myeloproxidase (MPO). People with high levels of MPO in their blood are up to twice as likely to suffer heart attacks as those with lower levels, according to Cleveland HeartLab. MPO is an inflammatory enzyme released into the bloodstream at areas of blood-vessel injury, such as vulnerable plaque that could cause a heart attack. In the study, this marker was the most predictive of short-term heart attack risk.
- Lp-PLA2. The second most predictive marker in the study, Lp-PLA2 levels, if elevated, can be an indicator of elevated near-term risk for either a heart attack or stroke.
- Hs-CRP. Also known as high-sensitivity C-reactive protein, this marker has been linked to increased heart attack risk in many studies and is included in the Reynolds Risk Score, a tool medical providers use to calculate patients’ future risk for heart attack, stroke, or other major heart disease in the next ten years. However, there can also be other reasons why Hs-CRP may rise, such as an infection, points out Doneen.