Every year more than 735,000 Americans have a heart attack. Heart disease kills 600,000 Americans. Now, breakthrough technology that is helping detect heart disease in a fraction of a second and saving lives.
Mary Rademacher knew she was having a problem with her heart.
“I could feel my heart beating, I noticed some things weren’t quite right, I noticed some irregularity, I would feel tired; sometimes faint,” described Rademacher.
Instead of an invasive heart catheterization, doctors had a new noninvasive tool at their disposal; a 256-slice CT scanner. It takes 4-dimensional high definition images in about one-third of a second, with one pass around the heart. Some older systems take up to 16 rotations.
Ambarish Gopal, MD, the medical director of Advanced Cardiovascular Imaging CT Program at Heart Hospital Baylor Plano, told Ivanhoe, “We have great quality images with much less radiation. This probably might be the single most powerful test because we are not only able to look at the plumbing system of the heart, we can look at the whole cardiac system, including the cardiac valves.”
The new scanner can see calcium buildup inside the coronary, even before people have symptoms. The imaging ruled out blockage. Rademacher’s arrhythmia was fixed with medicine and a minor procedure.
“It is a life saver, and it’s so simple,” said Rademacher.
Dr. Gopal detailed, “It does save lives because if you do find early plaque formations, calcium buildup, we are able to identify early coronary artery disease.”
This can lead to lifestyle changes that can reduce coronary artery disease and save lives.
The Heart Hospital in Texas is offering the new CT coronary calcium score along with diagnosis for only $79. So far it is not reimbursed by insurance.
Contributors to this news report include: Cyndy McGrath, Supervising Producer; Don Wall, Field Producer; Milvionne Chery, Assistant Producer; Tony D’Astoli, Editor; Mark Montgomery, Videographer.
BACKGROUND: Heart disease is the leading cause of death for both men and women. About 735,000 people have a heart attack every year in the United States and 600,000 people die from it. Coronary heart disease is the most common type of heart disease, killing over 370,000 people annually. Coronary heart disease is caused by plaque buildup in the walls of the arteries that supply blood to the heart and other parts of the body. Too much plaque buildup can cause the inside of the arteries to become narrow and make it difficult for blood to flow through a person’s body.
(Source: http://www.cdc.gov/heartdisease/facts.htm)
HEART CATHETERIZATION: The earlier heart disease is detected, the easier it is to treat. Thus, doctors may recommend a heart catheterization for patients to determine their risk for heart disease. During the procedure, a thin, hollow tube called a catheter is inserted into a large blood vessel that leads to the heart. Through the procedure, the pressure and blood flow in the heart can be measured. A contrast dye visible in X-rays is injected through the catheter and x-ray images show the dye as it flows through the heart arteries. This contrast dye shows where arteries are blocked. After the procedure, the patient will go to a recovery room for a few hours where they will have you lie flat. Heart catheterization is usually very safe and only a small number of people have minor problems. Some develop bruises where the catheter had been inserted and the contrast dye that makes the arteries show up on X-rays causes some people to feel sick to their stomachs, get itchy or develop hives.
(Source: http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Cardiac-Catheterization_UCM_451486_Article.jsp#.V8CrTvkrIdU)
NEW TECHNOLOGY: A heart scan, also known as a coronary calcium scan, is a noninvasive way to determine a person’s risk of developing heart disease. A heart scan is a specialized X-ray test that provides pictures of a person’s heart that can enable a doctor to detect and measure calcium-containing plaque in the arteries. The newest and most powerful heart scan is the 256-slice CT scanner. It takes 4D images of the heart in under one second with only one pass of the heart. With this scanner doctors can look at the whole cardiac system, including the cardiac valves. Compared to heart catheterization, heart scans are not a procedure so there is no recovery time.
(Source: Ambarish Gopal, MD)
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Public Relations
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Ambarish Gopal, M.D., FACC, FSCCT, FSCAI, Medical Director of Advanced Cardiovascular Imaging CT Program at The Heart Hospital Baylor Plano in Texas, talks about a new technology that is helping to detect heart disease months or years before the patient shows any symptoms.
Interview conducted by Ivanhoe Broadcast News in June 2016.
Did you start off by being a Cardiologist or did you move in the direction of being an imaging specialist?
Dr. Gopal: I’m a Clinical and Interventional Cardiologist with advanced training in imaging.
I guess the last twenty five, thirty years that probably didn’t exist.
Dr. Gopal: That’s correct. Years ago, everything would be taken care of by the general cardiologist. Now we have subspecialization and this allows us to choose our specialty fields.
This machine behind you, what is it and what does it do?
Dr. Gopal: It is known as a CT scanner or a computed tomographic scanner. Essentially, the CT scanner makes very thin slices of the human body, particularly in a certain organ of interest. The one behind us is one of the latest generation scanners. It’s a 256-slice CT scanner which is designed to make high quality images with excellent speed, and fast imaging.
This machine and the way this technology is advancing, is this a medical breakthrough and if it is why?
Dr. Gopal: It is. About 10 to 15 years ago this was basically a dream. Everyone wanted to have a great test for looking inside the heart, looking at the arteries without having to go inside with catheters, which is an invasive procedure. We wanted to have a very noninvasive way of looking at the organs of interest, particularly the heart. Technology now allows us to make very high quality images without the need for an invasive technique.
Is it a medical breakthrough and why?
Dr. Gopal: Yes, it is a medical breakthrough for the reason that this is completely noninvasive. This technology helps us save a guest or a patient a particular procedure which could be invasive otherwise.
These scanners are used for the entire body right?
Dr. Gopal: That is correct. These scanners are used for any part of the body. Imaging for the heart is very challenging because the heart is a dynamic organ. The heart has to move — that’s what it’s supposed to do. In order for us to image the heart we need very fast imaging, sort of like high speed photography. You virtually freeze the heart while it’s in motion. Then we can look at different areas of the heart in high definition and derive the information that we need.
How much better is the information that you are getting today than you were before you had the device?
Dr. Gopal: The earlier generations scanners had limited number of detectors. First was the 16- slice scanner, and then came a 64-slice scanner. Now this is a 256-slice scanner. The average length that is needed to scan a heart is approximately twelve centimeters to fifteen centimeters depending on somebody’s size of the heart, and the 256-slice scanners accomplish this area needed to scan much better and faster than the scanners with lesser number of detectors…better quality imaging with faster speeds. The speed of this scanner is less than one third of the second.
The earlier generation scanners had to go around the body numerous times and would be slower and also put out a lot of radiation for the patient. The older scanners were uncomfortable because the longer scanning time required the patients to hold their breath longer. Then, the 64-slice scanner was developed and it was a great improvement over the 16-slice scanner. However, the 64-slice scanner would roughly require about three stacks of the 64-slice data to make one complete picture of the heart. The 256-slice scanner actually covers 16 centimeters full cardiac coverage in one single heartbeat.
Essentially the scanner which uses radiation I guess to take the images, looks like a camera?
Dr. Gopal: That’s correct. The CT scanner is like a camera using enhanced imaging with X-ray technology. Radiation is delivered during the scan. This was a great concern with the earlier generation scanners which went around the patient many times with the radiation beam turned on all the time. Currently the 256-slice scanner will be just one heartbeat acquisition…just one spin around the heart. We have great quality images with much less radiation. This scanner gives probably one third of the radiation dose of our previous generation 64-slice scanner.
You know we been hearing about radiation and the issues associated with radiation for a long time. Is there data that shows that x-rays and scanners and things actually contribute to abnormalities and cause problems?
Dr. Gopal: That’s a great question. Radiation has always been a concern in two different ways. If there is a certain dose of radiation that is very high, it can actually cause acute injuries. That is a different kind of radiation injury.
The one that concerns us in medical imaging, particularly with a CT scan or in the cardiac catheterization laboratory, is called the stochastic type of risk. In other words, it is the probability that a certain radiation exposure might translate to that person having possibly a cancer later on in life.
The current data that we use for calculating this risk is based on the survivors of the atomic bomb incident. At the time those survivors did receive radiation doses which were very high… for this measurement we go by a term called milliSieverts, which basically defines what is the effective radiation dose that is delivered to the body and how much it can probably cause cancer later on in life. This is a probabilistic model with no data, and in comparison to this model the medical scans are much less radiation. We extrapolate information from that data from the survivors of the nuclear bomb to predict whether a future cancer may result from an exposure to the CT scan. There is no solid data to show that truly there is a cancer that might happen because of a certain dose of exposure that the patient does have.
That’s interesting because we always talk about that as being such a big concern but there’s no real data that shows that it is a real problem.
Dr. Gopal: We look at radiation doses that we get day-to-day just by living in the continental United States — not at high altitudes. Daily we are exposed to about 3 to 3 ½ milliSieverts. This 256-slice scanner in the right acquisition setting when possible has radiation doses as low as 0.6 millisieverts. We do a particular type full cardiac imaging by prospective axial gating where we can actually virtually freeze the heart and look at the heart beat through the whole cardiac cycle using one heartbeat. We do this study with about 5 to 6 milliSieverts of radiation exposure. If this study were done on a 64-slice CT scanner, the radiation dose would be anywhere from 9 to 25 milliSieverts.
What are you able to see now in terms of I guess diagnosis or detection of issues, that you couldn’t do before?
Dr. Gopal: The cardiovascular system performs many functions for the heart. We look at the cardiovascular system as essentially three functional units. One is the plumbing system, the other one is the electrical system and the other one is a pump.
Looking at it as a plumbing system, we look at the coronary arteries or the arteries that supply the heart muscle. The coronary arteries move a lot and with this type of technology we can virtually freeze the coronary arteries to look inside the arteries in very high definition. We can see if there is a blockage or not. The true strength of this test is what’s called negative predictive value. This test becomes a very powerful because of its negative predictive value. If we are able to look at the arteries and exclude coronary artery disease, we can avoid sending the patient to an invasive procedure like a cardiac catheterization.
The CT scan has numerous applications. A study from the 256-slice CT scan helps the cardiac specialists who treat the heart’s electrical system plan their procedures. Using the 256-slice CT scan, they can develop high-resolution three-dimensional images allowing them to able to go inside the heart, navigate, go to the area that has an abnormal electrical spot and burn it off completely. This procedure may be used to fix an abnormal heart rhythm.
As a pump we are able to look at how the heart muscles are working and how the valves are working. This scanner is very useful in helping us treat valvular heart disease because it’s able to image the heart valves in high definition with excellent speed because of temporal resolution. We are able to see the valve open and close in real time. We are able to see the valve in excellent definition and we’re able to identify if there are any problems. This technology helps us to plan for the procedure ahead of time. The CT scan offers valuable pre-procedure guidance to properly select and screen patients who will derive the best benefit for a transcatheter aortic valve replacement or a transcatheter mitral valve replacement. It has a lot of pre-planning data…it’s like using a reliable GPS to guide our procedures.
Does that mean it’s speeding up the diagnosis and treatment of heart disease?
Dr. Gopal: It does help speed up and facilitate the diagnosis but most importantly, it offers valuable anatomic information whether that particular anatomy would be suitable for transcatheter therapy.
We’re going to meet one of your patients so tell us a little bit about her condition and how the scanner was able to help her.
Dr. Gopal: Mary was referred to me for symptoms of palpitations which primarily mean that the heart was beating fast and irregular. We had done initially a workup to check what might be causing this symptom and the workup did show she did have an irregular heartbeat.
We had to do some tests to check what might be causing this irregular beat. Whether there’s a blockage in the heart or whether there is a structural problem in the heart. We had done a stress test that had suggested there might be a blockage in the heart. This is where the CT scan really comes in to play. This is a person where your clinical suspicion of finding a blockage was not high; it was intermediate at best. CT scan plays a great role because we are able to use this test, use its negative predictive value, exclude any significant blockages in the coronary arteries and address the issue.
This way we could avoid an invasive procedure like a cardiac catheterization; this is why a CT scan is an effective gate keeper. When we did her test, she had completely normal coronaries. We were able to exclude an obstructive coronary problem that might have caused the electrical problem in the first place. Then subsequently further therapies did completely fix her rhythm problem and she is doing well now.
The advantage to her was what?
Dr. Gopal: We were able to get the answer in a very timely efficient manner. We were able to avoid an invasive procedure which involves putting in a catheter though an artery either in the wrist or in the leg. Then we thread the catheter through the artery, selectively get into the arteries that supply the heart muscle, inject contrast, and take pictures. It takes a lot of work to get that information we need but with the CT scan we were able to get it in less than one third of a second.
By doing that then she was not subjected to an invasive procedure.
Dr. Gopal: By doing the CT scan with a 256-slice scanner she was not subject to an invasive procedure.
I guess that’s an example of how it works on a daily basis with everybody right? You’re able to see things that you just couldn’t see any other way right?
Dr. Gopal: We are able to see things that we have not seen before with this kind of technology because it involves a lot of data collection. We also are able to get pictures of the lungs, other organs in the chest wall region and the upper abdomen. You know whatever we scan; we are able to at least look for any kind of incidental findings. For instance, we may be able to find a nodule or an early tumor in the making and take care of it in a timely manner before it causes problems later on in life. Most importantly it is because of the quality imaging with that remarkable speed, this is a breakthrough in our technology.
Does it save lives?
Dr. Gopal: If you find early plaque formation, we are able to identify early coronary artery disease or early arthrosclerosis. We can treat the patient with some medications that lessen the likelihood of the plaque rupturing and causing an acute heart attack.
It sounds like it would be a great thing to have as part of your routine physical as opposed to something that you just do because some symptom indicates it.
Dr. Gopal: That’s correct. It’s a useful tool in preventive cardiology just as we have tools for early cancer detection. We can use the CT technology as an early detection to find and define problems, and start addressing them in a timely manner.
To give you an example, early on in life we may develop a little bit of plaque deposition inside the arteries that supply the heart muscle. This is fatty plaque. As time goes by, the fatty plaque may get a little bit of fibrous tissue, become a little tougher. Now it is called a fibro fatty plaque. During times of stress, these areas may have a stress related ruptures of the plaques. As soon as these micro ruptures happen, the body’s defense mechanism actually start pulling osteoblasts, which are bone forming cells from the bone marrow. They actually come from the bone. Then, they help to seal off these little ruptures by building in calcium. That’s how we can develop calcium over time.
By finding these early calcium deposits in the coronary arteries we can find a person who is vulnerable for having these plaque ruptures. We are able to advise good lifestyle modifications. Diet, exercise, and sometimes we recommend statin therapy if needed. We may also recommend medicines that help stabilize this process, stabilize plaque ruptures.
We see patients coming to the emergency room with acute chest pain which happens because of these plaques rupture. It’s not a plaque that is a seventy percent or an eighty percent blocked that causes the heart attack in this setting. It is a plaque that may be only twenty percent or thirty percent (what is called nonobstructive plaque) that ruptures and then becomes very sticky. What would be a thirty percent blockage becomes a hundred percent blockage in no time and hence a heart attack. So by having this information ahead of time, we’re able to prevent, protect heart attacks from happening. A person who has coronary calcium essentially shows that they’ve been having some micro ruptures happening all along.
How accessible is it and how much does it cost for an individual patient? It seems like there’s some issues there in terms of availability. It sounds like we should all be getting one of these.
Dr. Gopal: One of the main tools that we use is coronary calcium scanning or CT calcium score, and this can be done by any CT scanner acquired correctly. The test is offered by The Heart Hospital Baylor Plano for $79 which includes the whole test and interpretation. It’s very subsidized because we want this to be available to all our guests to help prevent a heart attack or heart disease from happening.
You’re saying that anybody could say I want to get my heart scanned and pay $79 and get the advantage of all this?
Dr. Gopal: That is what we are offering here at The Heart Hospital Baylor Plano, namely the CT coronary calcium scan.
That seventy-nine dollars would also include the consult with you?
Dr. Gopal: Yes.
I’m not hearing too many good deals like that.
Dr. Gopal: That is right; we want to make this easily available for all our guests.
There are other tests and I’ve heard they don’t really do that well, like stress tests and electrocardiograms, those things don’t really work. That’s what I’ve been hearing.
Dr. Gopal: Yes.
What this scanner does, this scanner picks up things whereas those tests which we thought were measuring sort of the health of our hearts but those things don’t work, is that right?
Dr. Gopal: That’s right. You know that’s a great question, as we already know we have numerous tests available in cardiovascular medicine. Electrocardiograms, stress tests, stress nuclear studies, stress echocardiograms, monitors, cardiac CT, cardiac MRI and invasive cardiology with cardiac catheterization. We have a host of tests that are available to us.
Now the stress tests are powerful to find blockages that are truly tight. For instance, if a stress echo or a stress nuclear test comes back positive this gives us information that an artery supplying blood to the heart muscle may have a blockage more than seventy percent. Any blockage that is more than seventy percent is defined as being a severe blockage; we do call it significant disease. Stress tests can help diagnosis in this setting.
If a stress test comes back negative, it’s very likely that we don’t have severe plaque blockage but it doesn’t rule out the possibility of what are called non-obstructive plaques. We may have a blockage that is under fifty percent, it could be forty percent and stress tests would not pick this up. Whereas, the CT scan directly goes to the source, looks at the heart and then finds out if there is any early calcium buildup.
We do use stress tests for preoperative clearance for somebody having a surgery, a non-cardiac surgery. This gives the surgeon information whether this person’s risk for heart attack is low risk or medium risk or high risk. Doing a stress test before undergoing a non-cardiac surgery for instance, a hernia repair or a back surgery can be classified as being low risk if the person’s stress nuclear or stress echo came back okay. If a stress test does come back okay, we classify this patient as low risk for having a heart attack.
In the past ten or twenty years, we didn’t know heart attacks came in different flavors. Now we have heart attacks which almost are classified as five types. We have type one, two, three, four, five. I’ll just focus on the first two types; Type I and Type II. Now Type II MI or Type II Myocardial Infarction is a sudden kind of heart attack where a person does have a truly type blockage, a seventy percent or an eighty percent blockage in one of the arteries that supply the heart muscle.
During an operation a person may have lot of stress because of bleeding problems; the heart has to pump more to deliver blood to the target organs. If the person does have an eighty percent blockage, now that portion of the heart muscle may suffer a lot of oxygen deficiency because the demand exceeds what that particular artery could supply. There is potential that this person could have a heart attack. This is diagnosed by doing blood tests that does show elevation in troponins or one of those other cardiac enzymes. This is called a supply and demand heart attack or a Type II heart attack.
Would this device pick that up?
Dr. Gopal: It will pick it up and the CT scan would pick up the other kind of heart attack that could happen, a Type I MI or the Type I Myocardial Infarction. With a Type I heart attack, a person does have a blockage which may be only thirty percent. If a thirty percent plaque ruptures when stressed, the ruptures bring out all the sticky substances in to the artery. This rupture starts acting like a magnet, pulling in stuff and making a blood clot fast. Then a thirty percent may become a hundred percent or blocked or tight. This person could have a heart attack. That is called a Type I heart attack due to plaque instability.
In my practice I usually do recommend putting these patients on a low dose statin therapy. Because not only the statins lower bad cholesterol in the bloodstream, they also have a direct anti-inflammatory effect on these non-obstructive plaques. The medications have a pacifying effect, stabilizing the plaques and helping prevent a possible rupture that might potentially happen at the time of surgery or after surgery with stress. If such patients are also started on a low dose beta blocker (when not contraindicated) at least a week or two before the surgery, beta blockers being also blood pressure medicines can have a very pacifying effect on the cardiovascular system. They also help reduce stress on these plaques and potentially prevent plaque ruptures.
Has there ever been a better diagnostic tool than this?
Dr. Gopal: This might be one of the most powerful tests currently available because we can look at the plumbing system of the heart plus the whole cardiac system including the cardiac valves. We also can pick up any kind of incidental findings of early cancer at the same time with much less radiation.
Is this among the best diagnostic tool that we have right now.
Dr. Gopal: The 256-slice CT has sixteen centimeters, one beat full cardiac coverage, much less radiation, high definition imaging, really fast with advanced spatial and temporal resolution. Spatial resolution is the ability to look at very small objects in pristine detail, and temporal resolution is the time need to make the pictures…and is the element of time. This machine makes scanning very easy for patients because they do not have to hold their breath for twenty seconds or thirty seconds as they did before.
