A set of newly discovered biomarkers may help physicians predict when people with heart disease are likely to have a heart attack, providing a potential preventative strategy against one of the nation’s biggest killers.
Dr. Oxana Galenko, a researcher at the Intermountain Medical Center Heart Institute Cardiovascular Research Laboratory and lead author of the new study, said that the findings could transform care for the 715,000 Americans who suffer a heart attack each year. "It's always been a mystery trying to identify people with heart disease who are at imminent risk of having a heart attack," she explained in a press release. "Currently, there's no blood test that allows us to say, 'yes, this person will likely have a heart attack in the near future'. But identifying what happens to these markers has given us a place to start."
The study, which was presented at the 2014 American College of Cardiology Scientific Sessions in Washington, DC, used data from the Intermountain Heart Study Registry — a vast library of blood samples dating back to 2006. Today, the registry contains DNA from more than 30,000 cardiovascular disease patients. Galenko and colleagues looked at data from 30 patients who had suffered a heart attack within 44 days of having their blood collected.
While evaluating factors like age, ethnicity, gender, cholesterol levels, and blood pressure, the team noticed that two so-called microRNA markers — 122 and 126 — dropped dramatically about two week prior to the attack. According to Galenko, this suggests that these microRNAs have a protective effect against cardiovascular events.
"MicroRNAs turn things off,” she explained. “Whatever they usually turn off in people with heart disease before a heart attack isn't being turned off when microRNA levels are reduced, which may be causing something else to be activated.”
"MicroRNAs act like a watch dog, and when their levels are reduced, heart disease takes a turn for the worse and heart attacks are likely to occur,” she added.
Preempting Heart Disease
According to the Centers for Disease Control and Prevention, cardiovascular disease is currently the leading cause of death in the United States, killing about 600,000 each year. That’s about one-fourth of all recorded fatalities. On average, deaths and illnesses associated with coronary heart disease cost the nation $109 billion annually.
The authors hope that the new study will take scientists one step closer to a reliable screening technique. "Ultimately, our goal is to develop a test that predicts when a heart attack is going to occur in patients with heart disease," Galenko told reporters. "This would help physicians intervene proactively and stop heart attacks from happening.”