People at higher risk for heart attacks and strokes may be easier for doctors to spot in the future through testing for a specific type of cell.
Endothelial cells make up a thin layer lining the inside of the heart and all blood vessels and arteries. These impact clotting, how vessels expand and contract and play a role in the immune system.
Cardiovascular problems can cause these cells to rupture and flake off from the vessel and float in the blood, research shows. Research, including a study published in the medical journal PLOS One, indicates that if endothelial cells exist in higher numbers in the blood, it might be an early indication of potential problems like heart disease or risk of stroke.
Doctors believe the inflammation that happens when the cells break away from the vessel walls increases the chances of blood clots and slows blood flow, contributing to cardiovascular issues.
In short, testing for the presence of endothelial cells in blood might help predict heart attacks and strokes, according to The Scripps Research Institute, one of the world's largest not-for-profit biomedical research companies.
When a potential cardiology patient now goes to the hospital, doctors assess his thrombolysis in myocardial infarction, or TIMI, and HEART (history, electrocardiogram anomalies, the patient's age, risk factors present and elevated troponin, a protein complex involved in muscle contraction) scores to help determine the severity of his condition.
Test yet to be FDA approved
“Ultimately what this (test) is is another method of tracking,” said Kevin Roesch, administrative director of cardiovascular services for Franciscan Health. “When endothelial cells circulate at a higher level it is because they are being discarded because of inflammation that was in a blood vessel or within plaque or stable angina.”
Developments in the last few years have given doctors the ability to assess endothelial health through a relatively simple blood test. In the past, the blood vessel had to be surgically opened.
The “fluid biopsy” (the blood test), called the high-definition circulating endothelial cell assay, was developed by Scripps in 2014 and hasn’t yet gained approval by the Food and Drug Administration.
“A lot of this still needs to be validated,” Dr. Jay Shah said. “First of all, which population would benefit from the test, and No. 2, when you get the test and you get a result, what are you going to do with that? That’s still up for debate.”
Shah is medical director of the heart valve center, director of echocardiography and medical director of cardiac rehabilitation at Porter Regional Hospital. He’s also part of the American Heart Association’s speaker’s bureau.
He said a cardiologist already tells his or her patients to lose weight, not smoke, manage their diet and exercise.
“Right now, in 2018, there is no guideline that has been put out by the American Heart Association or the American College of Cardiology based off of cloud data that says 'Get this test in this patient population and then, based off of that, put them on drug X,’” Shah said. “We don’t have that data.”
Shah doesn’t perform the test and isn’t aware of anyone in the area who does.
Front of mind moving forward
Dr. Andre Artis, cardiologist and medical director at the heart and vascular institute at Methodist Hospitals, said he’s been considering the procedure since it was discussed at a preventative cardiology meeting last February.
“The biggest hurdle is figuring out what resources are necessary and whether or not it's a resource that we can afford at this time,” Artis said. “It's something that's kind of on the radar, but our windshield gets hit with so many new developments that you sort of prioritize what you think, from your perspective, is the most important. Though this is important.”
A blood test is certainly easier on a patient than most current heart-health screenings and cardiograms and may even be cheaper, Shah said.
But even as blood testing becomes more accessible and widespread, it’s not something that the average person needs to have done without the suggestion of a doctor.
“We don’t have the data to support mass screening of the entire population,” Shah said. “The jury’s still out on who should get that test. What guides the decision-making is looking at underlying risk factors such as diabetes, tobacco use, hypertension and also family history, in particular family history of premature vascular disease.”
The procedure is one of many things that may be a part of cardiology in the future.
“I think it’s very important that we treat heart issues after they happen, but I think people would agree that the best thing to do is to try to prevent it, and that is where medicine and in particular cardiology is heading,” Shah said. “If there’s testing that can assess risk in a particular patient, and we can get outcome data that this person would benefit from different therapies to prevent that heart attack, prevent that stroke, absolutely that is where this is headed.”
“Whatever we can do to prevent disease from happening in the future, I think, is the direction that our organizations are headed,” Artis said. “And this certainly is one of the tools that I think will probably be in the front of the mind for a lot of our clinicians for the next probably five or 10 years.”