WebMD Live Events Transcript
Cardiovascular disease is the leading cause of death for both men and women in the United States. Doctors are working to find new techniques to diagnose and treat without invasive surgeries. We discussed the latest nonsurgical treatments for heart disease with cardiologist E. Murat Tuzcu, MD, from The Cleveland Clinic Heart Center on July 26, 2005.
The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.
Welcome to WebMD Live. Our guest today is E. Murat Tuzcu, MD, a Cleveland Clinic Heart Center interventional cardiologist. He is here to discuss the latest nonsurgical advancements in heart care.
Dr. Tuzcu, can you explain your work in the catheter lab and how it is helping you and your colleagues care for patients with heart disease?
More than half a century ago, doctors and cardiologists started to diagnose heart disease through catheterization: they put long, tiny tubes, called catheters, through the blood vessels of the leg, up to the heart. There they injected special dyes, and took pictures of the heart and the blood vessels. That was called angiography.
Over the years this basic technique allowed cardiologists to expand their diagnostic abilities and also do some treatments. For example:
- They started using balloons to open blocked arteries which bring blood to the heart (balloon angioplasty).
- Larger balloons were used to open narrowed heart valves (balloon valvioplasty). In the near future, we'll be able to put in artificial heart valves to repair some narrow valves.
- More recently, we thread devices through catheters and into the heart to repair congenital heart defects (such as holes in the heart).
As you see, the profession called interventional cardiology has a very large scope and in a nutshell, it means to treat many, many heart diseases through tiny tubes inserted through the leg or the arm -- diseases that used to be in the domain of heart surgery. So that's what I do.
What are the advantages to working via catheter rather than simply opening the heart?
The major advantages are avoiding the problems associated with open heart surgery, the generally long hospital stays (anywhere from 5 to 8 days), and the weeks needed to recuperate from open heart surgery.
Moreover, many patients, particularly those with other issues, or elderly patients, may have serious complications or die after surgery. Treatments done through catheters generally require only an overnight hospital stay, have much shorter recovery times, are generally less uncomfortable, and in many cases, may have less risk of complications and death.
Having said this, it is very important to understand that a cardiologist should always keep in mind the available treatment options, be it from surgery or through the catheter or by medications, and choose the one or the ones that suit that particular patient best.
|"The World Health Organization declared that coronary artery disease will be the No. 1 killer of the world in the year 2020."|
So I would not present the interventional cardiologist's work as a competitor to the surgeon's work, but I rather like to think these are all complementary tools in our toolbox when we help our patients.
What types of heart disease can be treated through catheterization?
The oldest and most widely used catheter treatment is treating blockages of the blood vessels that take blood to the heart. These blood vessels are called coronary arteries, and the blockages of these coronary arteries is called coronary artery disease.
This is the No. 1 killer in our country, as well as most of the world. The World Health Organization declared that coronary artery disease will be the No. 1 killer of the world in the year 2020.
This is an immense health care problem. For the last 20 years we've made tremendous advances in the treatment of coronary artery disease using catheter techniques.
Nowadays, most of the patients that come to us with chest pain or heart attacks are diagnosed by coronary angiography -- that is, taking pictures of the blood vessels supplying the heart. Most of the time, the narrowing that causes heart attack or chest pain is treated by using special devices called stents. Let me explain what a stent is.
If we go back to early '80s, when we were doing treatments using just balloons, we were able to open a blocked artery by stretching the blood vessel and by compressing the plaque that was narrowing the opening of the blood vessel. Unfortunately, three to five patients out of ten on whom we used technique, were coming back to our offices with recurrent chest pain within six months. We called this restenosis, meaning "narrowing again."
The way to solve this problem took more than a decade -- that's when we came up with devices called stents. Stents are tiny, miniaturized mesh cylinders that act as a scaffolding device within the blood vessel.
Think of the blood vessel as a three-lane highway going through a tunnel. The tunnel wall can get an accumulation on it which encroaches on the lanes, occupying two of the three lanes. What we do is put a mesh tube in there, and, with a balloon, expand it, forcing the accumulation back to the tunnel wall. We create a new opening and keep it intact because this little mesh cylinder doesn't allow the tunnel to be narrowed again.
The 1990s is the time of stents, but we also saw some renarrowing after stents, with about 15% of patients requiring repeat procedures. Nowadays we have new stents that are treated with special medications. They are called drug-eluding stents, which not only prevent the blood vessel compression, but also prevent scar tissue formation within the stent.
Nowadays patients who receive a drug-eluding stent have a 5% or less risk of renarrowing. This new technology, which can be applied with very small risk and offers an excellent long-term outcome, increased the number of patients treated by catheter rather than surgery.
So, this is the most common catheter application for heart disease. There are others I would be happy to talk about when other questions come up.
My mom had to have a stent put in even though she previously had a quadruple bypass. Is this normal? And how long is a stent supposed to last? She is very careful about her diet and exercise and takes her meds.
Bypass surgery utilizes blood vessels that are taken either from the inner chest or the arms or the legs. The risk of renarrowing or blockage of the particular bypass differs depending on the blood vessel used.
We know that the blood vessels taken from the legs have a risk of getting blocked about 50% of the time, seven to 10 years after surgery. You look at patients one year after they've had bypass surgery and 10% of the bypasses taken from the legs are blocked.
The blood vessels coming from the inner chest, called mammary arteries, are much, much better in staying open long term; unfortunately we only have two of them.
So a substantial number of the patients we use stents on today are those who have had prior bypass surgery. It's wonderful we have this technology so we don't have to subject these patients to a second open heart surgery.
I think it's very important for your mother to adhere to a healthy lifestyle -- healthy eating, regular exercise, and following the doctor's recommendation for aggressive medical therapy. This will certainly slow and even stop the progression of artherosclerosis, or hardening of the arteries and prevent heart attacks and heart disease.
Is the stent that has medicine built-in the best option if you have to have a stent? Is this now the standard?
The drug-eluding stents are the standard for most of the patients that require treatment by catheter.
For those blood vessels that are very big -- larger than 3.5 millimeters to 4 millimeters in diameter -- they'll probably do as well with the older stents. So although there are some exceptions, over 90% of the stents that are used in the U.S. today are drug- eluding stents.
|"Another new development in the last few years is ultrasound from within the heart."|
How is imaging being used to help treat heart disease?
We use imaging with coronary angiography, which I talked about earlier. We use X-rays and fill the blood vessels or the chambers of the heart temporarily with a dye containing iodine. That's how we image the blood vessels and heart chambers during catheterization.
It is important to understand that we use ultrasound quite frequently when preparing patients for this type of treatment, and during the treatment. There has been exciting developments in ultrasound technology that allows us better imaging in the catheter lab.
We are able to go inside those tiny blood vessels, the coronary arteries, by a miniaturized ultrasound wire and get exquisite pictures of the wall of the blood vessel. I want to make an analogy: If we go back to the three-lane highway and tunnel, by using the ultrasound wire we are able to see inside the wall of the tunnel and to see very early on the hardening of the arteries. That gives us tremendous insight about the coronary artery disease.
Another new development in the last few years is ultrasound from within the heart. We now have catheters that carry ultrasound transfusers that we can thread from the leg, up inside the heart, and which give us clear pictures. We use this technology when we insert devices to repair heart defects; we use this ultrasound technology (called intracardic echocardiogram), when we do work on the heart valve.
In short, angiography with ultrasound are the two most common imaging modalities that we use in the catheter laboratory.
What does an echocardiogram measure?
Echocardiogram is the moving ultrasound picture of the heart. It allows us to see the contraction and relaxation of the heart muscle, so we get a very good idea if any part of the heart vessel is not working as it is supposed to.
As an example, if somebody had a heart attack, an echocardiogram would show relative weakness in the front part of the heart, compared to the back or the sides.
Echocardiogram also provides excellent images of the heart valve, how they open and close, how much blood goes through them, it shows whether they close appropriately or whether the valves leak. Echocardiogram is the diagnostic modality of choice in valvular heart disease and also provides very valuable diagnostic information in a variety of heart birth defects.
Please discuss alternatives to open heart surgery for replacing valves.
This is a very exciting topic. Let me just take a minute to give a brief background about heart valves.
The heart can be considered as two townhouses each with two stories, adjacent to each other. Both houses have an upper room and a lower room.
The upper rooms receive the blood; they act as reservoirs. The lower rooms pump the blood out; they act as pumping chambers. The blood that comes to the upper rooms is sent to the lower rooms through valves.
The one on the left side is the mitral valve, on the right is the tricuspid valve. The blood that comes through these valves, down to the lower rooms, is pumped out through two separate doors: the aortic and the pulmonary valve.
Now, diseases of the valves of the left side, the mitral and aortic valve, are quite common and most of these disease are treated by surgery to replace these vales. Over the last several years there are efforts to replace these valves by catheter.
|"We are investigating the repairing of the mitral valve through a catheter."|
About four years ago a doctor in France used catheterization to thread an artificial valve inside a narrowed aortic valve and got very good results. All of his patients, about 20 of them, were extremely sick, being kept alive in the coronary care unit, and he was able to save many lives. It's a very new experimental technique. This technology is being investigated in the U.S. and other parts of the world for a wider application.
I think it will be several years before we improve this technique, the devices, and test the safety and efficacy of this treatment and decide that we can use this in a larger number of patients.
There is also a lot of work going on on the mitral valve -- the valve between the left upper and lower chambers. This valve is frequently dysfunctional because of an inability to close completely. We call it mitral insufficiency.
Surgeons, through open heart surgery, can repair that insufficiency, but again, this requires open heart surgery. There are efforts going on to see if we can go through the catheter, simulate what surgeons do, and repair the mitral valve without subjecting the patient to surgery.
There are different approaches to this problem. At least five to six big groups are engaged in this investigation. I think we will hear more and more about the development.
It sounds fantastic. Are you and your colleagues at the Cleveland Clinic attempting any of these experimental valve replacement techniques?
In the coming years, yes. We are of course investigating the repairing of the mitral valve through a catheter; studying repair of the aortic valve is underway.
I think it is important these investigations are done under the strict guidance and supervision of our hospital's review board and the FDA. It is very important we keep the safety and well-being of our patients our utmost priority in all these investigations.
What weight do you give calcification scores? My husband has a high score of 450. He's on Lipitor and his echocardiogram turned out well, yet he's a nervous wreck over his calcification score and alert to every little chest discomfort.
The calcium score is a representation of the extent of hardening in the blood vessel supplying the heart.
Returning to the highway and tunnel analogy, the tunnel wall contains the cholesterol and fatty elements we call artherosclerosis plaque. The more plaque we have, generally the higher calcium score we have. Having a higher calcium score does not necessarily mean you need heart catheterization or coronary angiography.
Your doctor may choose to perform a stress test and if it does not show a severe blockage in these blood vessels, then you should be treated aggressively, to slow or stop the progression of the plaque in your blood vessels. We talked about the advance in the cath lab in the last 30 years, but in the last 10 to 15 years we made tremendous advances in fighting arthrosclerosis or coronary artery disease using medications. These include:
We have very effective medications for these problems, but most importantly, we know that lifestyle changes -- including maintaining your ideal weight through healthy eating and exercise -- is very, very important in keeping the disease at bay.
Follow the recommendations of your cardiologist to the smallest detail. You will have a much better chance of having a long, healthy life with what we call aggressive risk factor modification.
Can you explain PFO and its relationship to strokes and migraines?
PFO is an acronym for patent foramen ovule. This is a communication between the upper rooms of the heart.
The blue blood on the right side and the red blood on the left side have their own circulations; they don t mix in the heart. When somebody has a PFO, there is a flap in the wall separating the upper rooms, allowing blue blood to mix with the red blood.
This opening is really not a hole but a potential hole; sometimes it allows tiny blood clots to go from the blue to the red circulation. That means they are in the arterial circulation. So if they go to the brain and block a tiny blood vessel, this results in a stroke.
Up to 40%-45% of patients having a stroke of unknown cause have PFO. Now there are investigations going on which aim to prove that closing these PFOs by inserting a device through the catheter is the way to go for these young to middle-aged people who have had strokes.
|"I think the catheter-based treatments of heart disease always provide us tremendous opportunities to help our patients."|
We have been using this technique for more than five years and we've noticed that some of these patients who we have closed this communication, this PFO, come back six months or a year after the procedure and tell us that they used to have migraines but they don't experience them any more. Or when they experience the migraines the intensity and severity is much less.
Now there is a study completed in England about migraines. We will learn some information when this study is published. There are several studies designed in the U.S. to see if closing these flapped openings in the heart by implanting a device is helpful to alleviate or to prevent migraines.
Dr. Tuzcu, do you have any final comments for us?
I think the catheter-based treatments of heart disease always provide us tremendous opportunities to help our patients. And the future is very bright because we will be able to address many other heart disease areas through this technique and avoid the problems associated with surgery.
I would like to add a very important point, particularly for coronary artery disease: It's important to try hard and to do everything we can to prevent the occurrence and the progression of coronary artery disease, in addition to the wonderful treatments that we have developed over the years. Thank you.
For more information, please visit The Cleveland Clinic Heart Center online at www.clevelandclinic.org/ heartcenter.
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