Imaging Study Seeks to Reform Heart Disease Prevention

Episode # 55
Uploaded: January 21, 2011
Running Time: 5:06

CARRINGTON: From the National Institutes of Health in Bethesda, Maryland, this is CLINICAL CENTER RADIO.

According to Dr. Christopher Sibley, a lead associate investigator at the NIH Clinical Center, by the time they are 60 or so, 50 percent of Americans will have a significant amount of plaque in their arteries.

SIBLEY: Atherosclerosis, or the partial blockage of arteries that ends up causing coronary artery disease or stroke, is the basic process that ends up being responsible for over half of the deaths of Americans.

CARRINGON: In fact, according to the Centers for Disease Control and Prevention, heart disease is the leading cause of death for both men and women, and in 2010, it cost the United States more than 300 billion dollars in health care services, medications, and lost productivity.

SIBLEY: The good news about it, if there is any in a scary number like that, is that it has a long process or long time period where it's quiet, before it will cause any of us a problem.

CARRINGTON: The trick to preventing atherosclerosis, heart attack, or stroke is to identify people with the major risk factors in this “quiet” period and make sure that they have access to cholesterol lowering medication that can help reduce the risk.

SIBLEY: The current way that we go about trying to determine who's at risk for having their first heart attack or stroke is by asking people a simple series of questions about the risk factors we just mentioned. How old are you? What's your blood pressure? How high is your cholesterol... among a couple of others. And those are pretty good at predicting your risk of having a heart attack or stroke in the next couple of years. The weak part of that is about a quarter of the people who have had their first heart attack would be considered low risk by traditional risk factors. So what we're trying to do is improve our ability to sort out, first of all whose likely to suffer a heart attack or stroke, and second, who stands to benefit the most from medications that lower cholesterol and reduce that risk.

CARRINGTON: In a study he is conducting at the NIH Clinical Center, Dr. Sibley's hopes to build upon the information learned by asking those questions. He will be using imaging technology to monitor and evaluate plaque buildup in the arteries while observing the impact of medication on that plaque.

SIBLEY: The interesting thing in our study is instead of trying to guess, based on risk factors what your chance of having early blockage or early atherosclerosis, we're actually looking directly at the arteries using MRI, magnetic resonance imaging, of the carotid arteries in the neck. We will compare people's arteries (pictured in) the early quiet atherosclerosis that we see with a large group of people we've studied previously, so we'll be able to compare the people in the study, to other people like them, to see if they fall into a lower level of atherosclerosis, an average level, or a higher amount than would be expected for their age.

CARRINGTON: Participants enrolled in this study are monitored for two years, and over the course of eight visits to the clinic they receive an MRI of the carotid arteries and a CT scan of the heart.

SIBLEY: Half of the patients will be treated just like you would if you saw your doctor, you take your statin medication, your cholesterol lowering medication, and we will just follow or watch what happens to your arteries. The other half of the people, we will adjust your cholesterol medication based on what we see in your arteries, based on the risk that we think that places you at. So the one major change compared to your usual doctors care is that we may change the dosage or kind of cholesterol lowering medication, it could be either lower or higher than you would normally get with your doctor.

CARRINGTON: The study is designed for individuals aged 55 and older, particularly those who have recently learned that they should be on cholesterol lowering medication. In the future, the team hopes to build upon the information gained in this study to use new imaging technology in more aspects of cardiac care.

SIBLEY: Of course we're not trying to throw away the risk factors that we've used traditionally, we're looking to improve on them. But based on what we'll learn from this study we'll be able to figure out better where that imaging should fit. Whether this should be used, you think of people who are used to going to the doctor for a colonoscopy to look for pollops, whether or not this could serve that same function where everybody could go in and have their arteries examined at one point to see if they fit in higher or lower risk factors.

CARRINGTON: If you would like more information about this study, or one of the 1,500 other studies offered at the NIH Clinical Center, log on to http://clinicalcenter.nih.gov. For this study, refer to protocol number 10-CC-0214. You may also call toll free 1-866-999-5553. From America's Clinical Research Hospital, this has been CLINICAL CENTER RADIO. In Bethesda, Maryland, I'm Kelli Carrington, at the National Institutes of Health, an agency of the United States Department of Health.

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