Iron in Coronary Artery Plaque could Predict Heart Attack
The amount of iron present in coronary artery plaque may be a predictor of heart attack risk, find researchers from the Mayo Clinic. No one has been able to predict dangerous forms of plaque from atherosclerosis inside that will rupture and lead to myocardial infarction and sudden death.
The scientists have now identified iron as a potential culprit; something that decades ago was thought to be the cause of plaque buildup and heart attack.
The researchers explain how tiny blood vessels, whose normal job is to nourish the blood vessel wall, can grow and feed atherosclerotic deposits in the arteries. If the vessels rupture, iron deposits into the growing plaque; making the plaque vulnerable. "This kind of plaque can bleed and heal, bleed and heal, depositing iron into the buildup," says cardiologist Birgit Kantor, M.D., the study's lead researcher. "This plaque is at risk of breaking up and causing a heart attack."
Iron Content in Dangerous Artery Plaque Significantly Higher
Mayo Clinic researchers conducted microscopic examinations of plaque from their biobank of heart arteries, separating them as unstable or stable; then matched them to the patient’s clinical history to see if they had died from a heart attack. Using a special stain, Yu Liu, M.D., Ph.D, the study’s first authors was able to identify significantly higher iron content in the kind of plaque that causes heart attack.
The researchers then took segments of diseased arteries, scanned them with a benchtop micro-CT scanner and looked for iron using 3D images. Dr. Kantor said, "There was a high correlation between the vulnerability of the plaque and the quantity of iron in it.”
The next step is to find scans that can detect iron in arterial plaque to predict heart attack risk and determine the need for intervention.
"We know that 70 percent of heart attacks are caused by unstable plaque, so what we really need for our patients is a way to identify the plaque that turns evil and puts them at jeopardy," says Dr. Kantor. "The scans we use now just show narrowing of heart arteries from plaque buildup but that doesn't tell us if the plaque inside those vessels walls is imminently dangerous."
It may be 5 to 10 years before scanners that detect iron deposits in plaque are available. Dr Kantor says, based on the study findings, the research teams thinks it’s possible to use iron as a marker for heart attack risk.