Heart Disease And Surgery
Heart Disease And Surgery
Rose Marie Robertson, MD, FAHA, FACC, FESC (Chief Science Officer and Past President of the Board of American Heart Association) gives expert video advice on: When is a heart transplant necessary?; Is angioplasty overused to treat coronary heart disease?; Are there alternative methods for treating heart disease? and more...
What is "angioplasty"?
Angioplasty is a procedure by which we can improve blood flow to the heart by widening the channel in a coronary artery that's partially blocked, sometimes even totally blocked. What we do during angioplasty is, if there's a blockage in the artery, we thread a tiny catheter up into the aorta (the main blood vessel). In angioplasty we thread it down from the artery in the leg into the artery right to the blockage, and right through that area of blockage so it's through that narrowed area. Around that catheter (a little tiny thin plastic tube) during angioplasty we have a little balloon. It's a longish balloon, at least a centimetre long, several centimetres sometimes. And during angioplasty we can then expand that balloon in the area where that artery is narrowed and that will squish the cholesterol (sort of more evenly distribute it), will stretch the artery a little bit, and when we take the balloon down, deflate it, and pull it back out after the angioplasty, we now have a wider channel through which blood can flow to supply the heart muscle.
What are "coronary stents"?
Coronary stents are thin metal networks, thin metal nets really, that we can use to help prop open a coronary artery. When we put an angiopasty catheter and balloon down into a coronary artery where there's a narrowing, we place the stent, which looks sometimes like a little bit of chicken wire, around the baloon. And then when we blow the balloon up, to expand that area in the coronary artery, the metal stent remains expanded. And when we deflate the balloon and pull it out, the stent stays in place and helps keep the artery open. The stent has that physical effect even if its just a plain, bare metal stent. But some stents also have medications on them that gradually come out of the stent and help keep that artery from closing up so quickly.People who get stents need to take blood thinning medications after they get the stent to make sure that no clots form within the stent and thus, within the coronary artery.
What is "heart bypass surgery" or "bypass graft surgery"?
Heart bypass surgery is a procedure in which a surgeon takes, either a vein from the arm or from the leg, or sometimes a small artery from the arm and uses that to create a channel around the blockage in the heart. One end of the vein or the artery is attached to the aorta, the main blood vessel coming out of the heart. And the other end is sown onto the coronary artery beyond where a blockage is. And then blood can flow freely from the aorta down to the heart muscle.Bypass operations can put bypasses into multiple arteries at a time. Several bypasses can be done during the same operation. And those bypasses have a good longevity. They tend to stay open quite well and to make people who have had multiple blockages, particularly multiple severe blockages in important large arteries safer in the long run.
How is bypass graft surgery performed?
Bypass graft surgery is done with the patient under anesthesia or asleep, and often on a heart/lung bypass machine that allows the heart to be still and quiet and actually stop beating during the period of time that the sewing is done. So when the graft is sewn from the aorta--sewn from the aorta down past the blockage onto the coronary artery, beyond the blockage. In some circumstances, the heart can be allowed to keep beating while a bypass graft is sewn in place. But exactly what kind of surgery is done depends on the individual and the surgeon and the particular circumstance to choose the way of doing it that is safest for the patient.
What are the risks and complications of bypass graft surgery?
The potential risks of bypass surgery can include serious risks, such as heart attacks and even death. But the risks are actually quite low in patients who don't have a lot of other complicated, complicating factors at the time that they have surgery, and in fact the risk is generally in the range of one percent or lower at institutions that do a lot of bypass surgery and have a lot of experience. One can expect to be sore, to have a sore chest after surgery, to take some weeks to recover and to heal up all the incisions, but in fact people get back to full activities, to doing all the things they did before bypass surgery once that initial healing period is over. Of course, we only suggest bypass surgery when we believe that the benefits to the patient far outway the risks. So patients who have coronary disease and need bypass surgery are patients in whom there's a substantial risk if they don't have surgery. Balancing the benefits and risks of any procedure is always an important thing to have your physician do and it's important to discuss that with your physician.
What is "valve surgery", and when is it required to treat a heart condition?
Valve surgery is another kind of heart surgery that's done to correct a structural problem in the heart. So, as opposed to coronary surgery, where we're operating on the outside of the heart really, in valve surgery we are operating inside the blood vessels in the heart. You can see here the aortic valve. Blood is being pumped out through the aortic valve by this chamber when it squeezes. Blood comes into the heart through the mitral valve and either of these valves can become either too tight over time or can develop leaks. There are many reasons why they might do that. And, in some cases, a leaking valve can be repaired by valve surgery. And, if it can't be repaired, it can be replaced with valve surgery. Likewise a valve that is too tight or is leaking - more commonly the aortic valve gets too tight but both can have that happen - that valve can also be replaced with valve surgery if the function of the valve is interfering with the overall ability of the heart to pump blood out to the body where it is needed.
When is a heart transplant necessary?
Heart transplantation is an effective way of treating end-stage heart failure. Patients really only need a heart transplant and are only referred for it when their heart disease is so serious that, without heart transplantation, they would die in a relatively short period of time - something like six months or so. It's difficult to find hearts for transplantation, and so we limit heart transplantation only to those patients who really are desperately in need of it. In general, heart transplants are needed when patients are in severe heart failure, sometimes because of coronary artery disease and either severe or multiple heart attacks, sometimes because of valvular heart disease, and sometimes because of heart muscle disease or cardiomyopathy.
How difficult is it to get a heart for a heart transplant?
Every year, just over 2 heart transplants are done in this country. In fact, thousands of people die while waiting for a heart transplant. The unfortunate thing is that they bury perfectly useful hearts. It's very important for people to know that their heart can be used to save a life when it's of no use to them anymore. So, when people are in auto accidents, when they die tragic deaths, but the heart is left intact, it's a tremendous benefit to someone else that is sitting in a hospital and waiting for a transplant who will otherwise die without it. To have that heart is the really supreme gift of life. People who are on transplant lists are there because they have devastating heart disease. They are, in fact, prioritized on those lists by how severe their heart disease is. The people at the top of the list are people who actually can't survive out of the hospital, who have to be in the hospital getting medications actively or they wouldn't be at the top of the list. So, the distribution of organs is really very fair, very appropriate and signing that organ donor line on the back of your driver's license is a tremendously important thing to do.
What is a "left ventricular assist device" and what does it treat?
A left ventricular assist device is a mechanical device that can substitute for a good bit of the pumping function of the left ventricle, the main pumping chamber of the heart. That chamber of the heart, this big, muscular organ, squeezes and pushes blood out through the aorta to the rest of the body, to the brain, to the kidneys, to the muscles, everywhere in the body. This is the part of the heart that is often affected by heart attack, by narrowings in the coronary arteries. If it's affected so much that it really can't provide the blood flow that the body needs, then a left ventricular assist device, which often takes blood out of the ventricle into a little pump and pumps it back into the aorta, lets the heart rest so that it can recover, but more often is used while a patient is waiting for transplant but is so sick that even with medications they can't get along by themselves. So it's a bridge to transplant.
Is angioplasty overused to treat coronary heart disease?
Angioplasty is a very effective way to provide increased blood flow to the heart and to reduce symptoms. However, there's been a recent large study, the COURAGE trial, that let us know that if patients have stable angina--that is their symptoms haven't changed in months, they've been about the same, but they're still troubled despite really very, very good medical regimens and very careful lifestyle changes that have made them as healthy as they can be. In that circumstance, they really are just as well off to continue with medications as they are to move ahead urgently to have an angioplasty. Now, if their symptoms aren't able to be controlled by anti-anginal medicines, it's perfectly reasonal to go ahead and have an angioplasty, but there doesn't need to be a rush to that in the way that physicians sometimes used to feel there was. So just seeing a severe narrowing in the artery doesn't necessarily mean you have to go and open it if you can treat the patient to a degree that satisfies them in terms of their lifestyle and if their symptoms aren't limiting.
Are there alternative methods for treating heart disease?
It's always worth looking for new methods for treating a disease that's as widespread and serious as heart disease. The best way to look at those ideas is to assess them in clinical trials, so that there are a number of complimentary and alternative methods that are currently being evaluated by the National Institutes of Health to see if they really are helpful, or if they're not. One can't simply take a method and start using it with the assumption that it's better, because in fact, not only could it cause harm, but it may keep people from following the treatments that we know are helpful. So it has to be shown to be better than what we have now. It's very important for that research to be done, and the NIH is currently at a lower level of funding than it's been in thirty five years. For the first time in thirty five years, funding at the NIH has actually fallen. So supporting the concept that biomedical research is a very important thing to do, and really the only way we find new discoveries is an important message for everyone to take to their congressmen.