Predicting Bad Hearts

Every year, more than 700,000 Americans have a heart attack. And 600,000 die of heart disease.

"Fully half of the people that are going to die in America are going to die of cardiovascular disease," Jeffrey M. Schussler, MD, Cardiologist at Baylor University Medical Center in Dallas, told Ivanhoe.

Now, researchers at Baylor Research Institute at Dallas have uncovered a biomarker that may help them spot the disease sooner; and they did it by pure accident.

"That's what made it really exciting for us because it was a totally unexpected finding," Caren Swift, RN, Research Nurse at Baylor Research Institute, told Ivanhoe.

While attempting to identify patients with a rare condition known as fabry disease, the investigators found the marker they were studying, GB3, was more common in people with heart disease.

"The higher the level of GB3 in the urine, the higher the risk of death," Raphael Schiffmann, MD, Institute for Metabolic Diseases at Baylor Research Institute, told Ivanhoe.

Because it's found in the urine, it could one day be a simple way to test for patients who are at risk of heart disease.

Catherine Traweek participated in the study. She didn't have heart disease, but she found she was a carrier for fabry.

"The more you know, the better off you are as far as your health is concerned," Traweek told Ivanhoe.

The investigators say they plan on studying the GB3 biomarker more to see if it will be a more accurate predictor than current methods, like stress tests.

BACKGROUND: Coronary arteries have a very important function of carrying blood to the heart, but for people with coronary artery disease (CAD), these arteries are damaged or diseased, causing blood flow to the heart to be restricted. Atherosclerosis, which is the hardening of arteries, is a common cause of these blockages because cholesterol-containing deposits called plaque begin to build up on the inner wall of the artery. Because the heart is not getting enough blood and oxygen, coronary artery disease can lead to angina, and if the blood flow is completely blocked, heart attack. (Source: www.mayoclinic.com)

RISKS FACTORS: In order to prevent coronary artery disease before real damage is done to the heart, people need to know the common risk factors for the disease. These risk factors include: smoking, diabetes, high blood pressure, a family history of heart disease, and high levels of LDL cholesterol. Women are also at an increased risk of CAD after menopause, while men's CAD risk rises after the age of 45. Lifestyle changes can help to control some of these risk factors, such as smoking and high cholesterol, but others are hereditary. People with a family history of heart disease should monitor their heart health closely and live a healthy lifestyle. (Source: www.heart.org)

NEW TECHNOLOGY: Researchers have potentially found a new way to detect for heart disease via a urine test. While trying to determine the relationship between a compound called GB3 and a rare condition called fabry disease, researchers at the Baylor Research Institute discovered that about 15 percent of patients with heart disease have elevated levels of GB3 in their urine. Down the road, it could be used along with stress tests to determine patients who have heart disease but are not necessarily showing any symptoms. Researchers are still examining the relationship between GB3 and heart disease, and are working toward a study and paper. (Dr. Raphael Schiffmann, Dr. Jeff Schussler)

Jeff Schussler, MDJeff Schussler, MD, Medical Director for the Cardiovascular ICU and Interventional Cardiologist, talks about a new test that could one day predict heart disease.

How many people do you see every day suffering from heart disease?  

Dr. Schussler: I see a lot of people who have cardiovascular disease. The majority of my practice deals with problems directly related to weakened hearts or blocked arteries. 

There are so many things that go into cardiovascular disease, not just one.  Can you name a few?

Dr. Schussler: Well, the biggest issues in cardiovascular disease are coronary disease and strokes. Half of the people in America are going to die of cardiovascular disease and that includes heart attacks and stroke. 

Right now, how do you test somebody for this?

Dr. Schussler: Sometimes we can't.  They show up in the emergency room having had their heart attack and we have to deal with it once the horse is out of the barn.  Ideally what we'd like is to prevent people from having their first heart attack.  It would be great if we could predict years before they have their problem, that they were going to have that problem and do things to try and mitigate that.  There are people who we know are at higher risk and the biggest problem is we can't tell what the future is going to hold. However, there are people who have high risk markers.One of the things that we're always looking for is a better, easier, cheaper test that can tell you what might happen in the future or see if you are in a high risk group.  We've had lipid markers, which tell you if your cholesterol is high or if your cholesterol is low.  In general if you have very high cholesterol or if you have bad family history, you're in a higher risk group, but none of these tests are perfect and we're always looking for additional information that can help us make that decision.

It's very time consuming right now when you get somebody who might be at risk. Do you give them the stress test, which is pretty time consuming test and I would assume probably kind of costly cause of the time?   

Dr. Schussler: A stress test is not that time comsumine, but at times it's also not very helpful. If you have someone who is having symptoms, stress tests are very good. However, in people who have no symptoms, stress tests are really not very good tests in discriminating who may or may not develop plaque in the future.  It's one of the big problems with stress tests. We've all had patients or known people who had a stress test that was normal one day and then had a heart attack several weeks later.  Stress tests are not as good at predicting the future like we would like them to be. 

Do you think a urine test like this could be helpful?

Dr. Schussler: I think it might. We are always looking for additional information and so anything that we can do that adds to the body of knowledge is really helpful.  So let's say for example, you're one of the people who comes in with lipids that are neither good nor bad.  What do you do with that? If there is some additional test that you can use, that may put you in a lower risk or a higher risk category that would be very helpful.

Do you think this test could change the course of those numbers? 

Dr. Schussler: That is one of the things that needs to be tested.  Once you have a study or test like this that looks at a group of people and finds a signal, you then have to take that information in a whole other group of people and say "okay, we're going to start out now; we're going to give the test to these people and then we're going to follow what happens and make decisions based on that information." It may turn out that this test is great for predicting how we treat people going forward and it may turn out that it's not as good as it looked like in the original study, but it at least gives us information in a different area.  We have looked at lipids before; we've looked at markers of inflammation; but this is looking at fats that come out in the urine in some different avenue for predicting future events. 

Do you think this could be like a front line kind of test for people, where they come into the cardiologist, they pee in the cup first and then you can go from there?  

Dr. Schussler: It could be.  One of the great things about this test is that it's easy. We're looking for inexpensive and we're looking for utility and so if you have a test that all it takes is to pee in a cup and you can get some information back that at least meets the requirements of being safe and easy and potentially inexpensive, then that's great.



Kristine Hughes

Baylor Health