Heart disease has been dubbed a “silent killer” because it can strike suddenly with no symptoms.
But proponents of a new blood test developed in the U.S. say they have developed an early warning system that could prevent heart attacks.
“You could be going around thinking you’re completely healthy, yet have ongoing disease in your coronary arteries,” said Dr. Douglas Harrington, a clinical professor at the University of Southern California’s Keck School of Medicine and CEO of GD Biosciences.
Harrington is in Vancouver for the 20th World Congress on Heart Disease at the Hyatt Regency Hotel.
On Saturday, he presented information about the novel test, called PULS, which stands for Protein Unstable Lesion Signature.
The blood test detects protein leaking from unstable lesions that develop in the arteries due to damaged cholesterol circulating in the blood stream.
The lesions of soft fatty plaques can become unstable if they develop a necrotic core, said Harrington. Because these lesions tend to be flat, they don’t typically obstruct blood flow — thus many patients would not experience chest pain that can warn of an upcoming heart attack.
But when those lesions rupture, they throw out blood clots that block arteries, causing a heart attack.
These ruptures are responsible for 75 per cent of all heart attacks, said Harrington. “But there hasn’t been a way to detect this process in the body until we developed this PULS test.”
Most testing today revolves around measuring cholesterol and other lipids in the blood.
Cholesterol is an important marker, said Harrington, but fails to capture the full picture of the heart’s health. In fact, 50 per cent of people hospitalized with heart attacks show normal levels of cholesterol, he pointed out.
“Cholesterol is important because if it’s elevated it tells you have a greater risk of developing heart disease. But those levels do not tell you if your heart already has injury.”
The new test, which is designed for people age 40 and older, measures nine protein markers to gauge the level of current injury in the heart.
Harrington compares the test to a car’s check-engine light: “It’s telling you there’s a problem but your car hasn’t developed symptoms yet.”
The test is the result of 15 years of research in the development of lesions in animals and humans in a collaborative project involving USC, Stanford University, the University of California at Los Angeles and other institutions.
It has been validated by four clinical trials with a total sampling population of 31,000, including a large medical research study called MESA, or Multi-Ethnic Study of Atherosclerosis, which was sponsored by the National Heart, Lung and Blood Institute at the National Institutes of Health.
Knowing the danger signs lurking in your arteries can help spur people to change their lifestyle and prevent heart attacks, said Harrington, a big believer in preventive medicine. “But you’ve got to know it’s there.”
PULS testing has been available in the U.S. since November, where it is covered by Medicare and some private insurance and costs about $200.
It is not yet available in Canada, although Harrington said his company plans to get in touch with Canadian laboratory services to get provincial approvals and make it available here.