A simple test that spots abnormal cells coming from the lining of blood vessels can predict a heart attack a week or two beforehand.
Heart attacks happen when fatty deposits in an artery burst open. A blood clot forms to seal the break, but if that gets too big, it blocks off blood flow.
Blood vessels are lined with ‘endothelial cells’ that control the ability of arteries to widen and prevent clots. When there are a lot of large, misshapen endothelial cells, a heart attack is imminent, the new study shows.
More than 2.5 million Americans experience a heart attack or stroke. While doctors can tell who's at risk – people with high blood pressure and cholesterol, who smoke, have diabetes, are overweight or sedentary – there's no way to tell when a heart attack is looming.
People often head to the hospital when they feel chest pain or pressure, only to be sent home when doctors can’t detect a problem with an EKG. They currently rely on the treadmill stress test, which can only determine if there’s an artery blockage – not if there’s a crack in the artery or if the plaque is poised for rupture.
(Basically, we can only tell if a person is currently experiencing or has recently experienced a heart attack.)
“The ability to diagnose an imminent heart attack has long been considered the holy grail of cardiovascular medicine,” study researcher Eric Topol from the Scripps Research Institute says in a release.
Sometimes people pass the stress test, only to have a heart attack in the next few days. To help flag these patients, Topol and colleagues developed a blood test with the help of 44 healthy volunteers and 50 patients who had gone to emergency rooms with heart attacks in San Diego.
- First, they isolated and counted ‘circulating endothelial cells’ (CECs) coming from the inner lining of blood vessels.
- Then using fluorescent images, they revealed that CECs from heart attack patients look very different from those in healthy people: abnormally large, misshapen, and contain more than one nucleus.
CEC levels in heart attack patients are over 400% higher than in healthy people. “These are sick cells that have been subjected to profound inflammation,” Topol explains.
(Pictured on the right, CECs from heart attack patients. On the left, normal CECs.)
The team hopes to have this test developed for commercial use within the next 2 years. AP reports:
Topol said his team soon will begin needed studies to learn how early those cells might appear before a heart attack, and if spotting them could allow use of clot-preventing drugs to ward off damage. Some San Diego emergency rooms will study an experimental blood test with chest-pain sufferers whose standard exams found no evidence of a heart attack.
In the future, patients at risk could have a nanosensor implanted in a vein to detect the abnormal cells and then send an alert to their phone.
The study was published in Science Translational Medicine today.
Image: Scripps Translational Science Institute