Ask the Heart Doctor: Aortic Valve Surgery

Podcast Transcript

Announcer:

Welcome to Love Your Heart, brought to you by Cleveland Clinic’s Sydell and Arnold Miller Family Heart, Vascular and Thoracic Institute. This podcast will explore disease prevention, testing, medical and surgical treatments, new innovations, and more. Enjoy.

Amar Krishnaswamy, MD:

Thank you everyone for joining us. This is the edition of Ask the Heart Doctor where we're going to focus on valvular heart disease from diagnosis to treatment. My name is Amar Krishnaswamy. I'm the Section Head of Interventional Cardiology, and I specialize in the transcatheter treatment of valvular heart disease. I'm joined today by a fantastic panel of colleagues and friends. We have Dr. Xiaoying Lou, who is a cardiac surgeon and an expert in aortic valve surgery. We have Dr. Tarek Malas, who is also a cardiac surgeon and an expert in mitral valve surgery. Dr. Serge Harb, who is one of our cardiac imagers and a specialist in the diagnosis and guidance of transcatheter heart procedures with cardiac imaging.

We appreciate your engagement in this program. We've received almost 250 different questions. We're going to try to do our best to answer as many of them as we can in a comprehensive fashion. But please, if there are questions we don't answer, feel free to reach out, and there will be contact information at the end of this program. So, Serge, I'm going to start out by asking you,  we have a very interesting question here. Does valve disease always progress if it starts out mild? If you can specifically address at every point the aorta, mitral valve, tricuspid valve?

Serge Harb, MD:

Not always. Some valve disease, whether it be aortic valve, mitral valve or tricuspid valve, can remain stable and mild. Others can progress and it's mainly related to patient-related factors and other associated conditions that can predispose someone to progress. That's why follow-up is crucial to determine which patients are going to progress, and to make sure that we are on track with the follow-up. Typically, what we do for follow-up is frequent visits, depending on the severity of the valve disease, which entails physical assessment, symptom assessment, and then usually echocardiography.

Amar Krishnaswamy, MD:

That's very helpful. Are there other tests, in addition to echocardiography, that may be helpful in trying to tease out whether the valvular disease is in the mild, moderate or severe range?

Serge Harb, MD:

This question comes up when there is a discrepancy between what the patient is reporting in terms of symptoms and what the echo is showing. Maybe sometimes, the patient is very symptomatic, and the echo doesn't show a significant valve disease. In these cases, we have additional testing that we can refer to, such as transesophageal echo, which is an echo through the mouth that takes a closer look at the valves. We can also have tomographic imaging with cardiac CT or cardiac MRI. Sometimes both. Also very importantly, as you know, hemodynamic assessments of valves, which you're an expert in, where we can see how much the valve condition is affecting the pressures in the heart and the patient's symptoms. Lastly, exercise stress testing, which puts the patient on a treadmill and we try to exert them. Because sometimes, the valve disease may appear to be mild at rest. But when we exert the patient, we can see much more significant valvular disease.

Amar Krishnaswamy, MD:

What I take from what you've said, which is I think a really important point for patients, is that sometimes, the initial phases of testing might not show a severe valve problem. But if there are symptoms that are still concerning, they should pursue further testing, perhaps sometimes even invasive testing, to better understand if the valve disease is in fact significant.

Serge Harb, MD:

So true. Actually, I've seen a patient recently where the outside echo, when she had the testing, showed only moderate disease. She was quite symptomatic, so she decided to come here for a second opinion. When we did repeat the initial echo, just because of how thorough our echocardiography is, we found out that actually, she did have severe mitral valve disease. Actually, I'm going to refer her to Dr. Malas for intervention.

Amar Krishnaswamy, MD:

That's very helpful, I think really instructive for patients. You mentioned a lot about symptoms. How do we know when a patient is ready to have treatment for their valve disease? Is it always based on symptoms, or are there other factors?

Serge Harb, MD:

I think there are three main determinants to when the patient would need an intervention. First and foremost is symptoms, as you mentioned, meaning chest pain, shortness of breath, fatigue, dizziness, palpitations, sometimes passing out. But also, sometimes evidence of heart damage. If you have a significant valve condition and then there is evidence of heart damage, then we sometimes refer patients for intervention, even if they are asymptomatic.

Lastly, in some conditions, even if the patient is asymptomatic and even if there is not yet evidence of heart damage, we can refer them for intervention. I would take, for example, the condition of severe mitral valve prolapse to severe mitral regurgitation. We know that it's a structural problem. We know that it will not get better. We know that our outcomes here, especially with surgeons like Dr. Malas, if we send them for mitral valve repair, we know that it's a very high success rate with very low complications. Similarly, with Dr. Lou, if it's a patient who has severe aortic dilation, even though there is no impact, there are no known symptoms, we worry about high-risk complications. We know that operations such as these are very low risk with Dr. Lou. This would be a patient that I would refer for surgery early on before complications arise.

Amar Krishnaswamy, MD:

It's very, very helpful understanding for our patients that are listening. As always of course, it's very patient-specific decision-making to understand the symptoms, the testing and what may or may not be necessary. Dr. Lou, can you help us walk through what does a surgical aortic valve replacement really entail for the patient?

Xiaoying Lou, MD:

The incision to get access to that surgical valve replacement can vary. Here at the Cleveland Clinic, I think one benefit is that we have some variations to that approach. If a patient is coming in for an isolated aortic valve replacement, we can offer a mini-sternotomy, meaning that we don't go through the entire breastbone but just a partial breastbone. Healing and all of those things and pain tends to be a little bit better for that patient. In addition, some surgeons also offer a right thoracotomy approach into access that. So, you don't necessarily have to end up with an entire, all the way down the breastbone incision. We get access to the heart that way. Then, in addition, we put the patient on the heart-lung bypass machine, which takes over the function of the heart and lungs during the operation. Then we make a small incision called an aortotomy at the side of the aorta.

We open that up, we get access to the valve itself, so that valve is just looking in our faces. Then we can analyze what's going on with that valve. Generally, patients are coming in for very severe aortic stenosis, so they have a lot of calcium or other deposits on that valve. We carefully remove those leaflets. We clean everything up nicely. We take up every little piece of calcium and literally, we'll be picking at these pieces of calcium and make sure that all of those get picked up appropriately. We irrigate everything, and all of those pieces are really important to be removed out of the patient. Once everything is nice and clean where that valve sits, we sew a valve back in, whether that's a mechanical valve or a tissue valve.

Amar Krishnaswamy, MD:

Very helpful, thanks for that understanding. You mentioned mechanical valve versus biologic valves. How do you make a decision about one or the other? Are there differences in how long these valves last?

Xiaoying Lou, MD:

When a patient comes in with aortic stenosis, that valve does need to be replaced. The options are in our prosthesis regimen, either a mechanical valve, which just means metal parts to that valve. And then a tissue valve, which can either be a cow valve or a pig valve. In the aortic valve position, we do a cow valve in general. The wear and tear of that valve is different for each of those prostheses.

We typically counsel that a mechanical valve is favored for a patient who's probably under the age of 55 or so, 50-55. The benefit of that mechanical valve is that, theoretically, it should last your whole life. But the drawback is that a patient has to be on a blood thinner called Coumadin® their whole life. That's a medicine that has to be taken every single day, and your blood has to be a certain level of thinness. We have better mechanical valves now, so your blood doesn't have to be quite as thin as it used to be. But it is still a mechanical valve that needs to have things that are carefully monitored in your bloodstream.

The alternative is a tissue valve, which is a cow valve in that position. We do know that once that cow valve goes in, there is a clock on that valve and that there is an expected wear and tear on that valve. Generally, the data says after about 15 to 20 years or so that valve needs something else done at that point.

Amar Krishnaswamy, MD:

Very helpful. Now, there are some patients, particularly those who have a bicuspid aortic valve, and whether that valve degenerates with aortic stenosis or aortic regurgitation. They may also have associated pathology of the aorta above the valve or aneurysm. How do you assess those patients? And do you do a surgery on the aneurysm and the valve at the same time?

Xiaoying Lou, MD:

Yes, great question. I think that's the benefit of coming into comprehensive centers, that we have some options for patients who come in with aortic valve leakiness or insufficiency. For instance, for the bicuspid patients who come in and they're often associated with aortopathy or aneurysms of the aorta, either at the level of the root or the ascending aorta or beyond. There are some options for patients who are younger and perhaps that valve could be repaired, rather than fully replaced. I think at the valve level for bicuspid valve, if it's not stenotic or calcified, compared to some other centers, we really try to repair those valves in young patients. There are various repair techniques. We, as the center, have published extensively on those repair techniques, and have found that they are as durable as patients who come in with a three-leaflet valve that end up getting repaired as well over time. That's a really good option for younger patients because the alternative would've been a mechanical valve.

Then in addition, that bicuspid valve is reasonable, working okay, but they have a root aneurysm. We offer valve sparing root replacements where we are able to keep the patient's valve, maybe do a little bit of plastic surgery tightening up here and there to prevent them from being severely insufficient, and then just replace the area around the root. Then also, we offer an ascending replacement, whatever you need at the same time. Our threshold for going in for that aneurysm is a little bit smaller if we're going in after the valve itself as well. Typically, we do an aneurysm replacement when the aneurysm is at 5 centimeters. For a valve, if we're doing the valve at the same time, we lower that to about 4.5 centimeters. We really try to offer a comprehensive approach for the patient at the first time of their surgery, to try to prevent them from needing multiple heart surgeries down the road. One is enough.

Amar Krishnaswamy, MD:

I think to summarize, we have a lot of different ways that we can access the chest for patients who require aortic valve surgery. I think most often in patients with an isolated aortic valve problem, you're approaching with a minimally invasive incision, which is a somewhat unique approach that us surgeons have here at the Cleveland Clinic. In those patients who require an aortic valve surgery and an aneurysm surgery, those also can often be approached by a minimally invasive incision, as I understand. Then the choice between a biologic valve and a mechanical valve is really, again, a patient-specific one. It takes into consideration factors like age, ability to tolerate blood thinners and so forth.

There are a number of questions here about transcatheter aortic valve replacement, so I'll try briefly to summarize. Transcatheter aortic valve replacement, or TAVR, is a procedure where most commonly we place a small catheter or a tube in the artery at the top of the thigh, whether the right leg or the left leg. Through that tube, we pass a catheter that has a valve on the end of it. There are a few different types of valves and sizes of valves that we can use. Again, these are all very patient-specific and based on an analysis of their imaging. The procedure is generally performed under what we call a conscious sedation or a monitored anesthesia care. There is an anesthesia team to keep the patient comfortable, but they're not under full anesthesia or a breathing tube or anything like that. We place the valve from the leg into the aortic position, and we expand the valve into place, pushing aside the native aortic valve and leaving in place this new prosthetic. We don't actually take out the native aortic valve, but it just gets pushed aside. The prosthetic is always a biologic prosthetic or a bioprosthetic valve. It doesn't necessarily require anticoagulation. Usually, we just continue the patients on a baby aspirin. For the most part, the procedure takes about 45 minutes, and at least at Cleveland Clinic, about half of our patients go home on the same day as their procedure.

There's a question here about if you have had a prior aortic valve replacement, can you have a TAVR? If the aortic valve replacement was a bioprosthetic valve, we can do a TAVR routinely as we would in a native aortic valve. We simply place that TAVR inside of the surgical valve and expand it into place. If the surgical valve is a mechanical valve, that is not something that can be replaced at the current time with a transcatheter strategy.

Another question here, can you have TAVR if you're at a low risk for surgery? For the most part in the current era, on the basis of trials that have compared TAVR to surgical valve replacement at all levels of risk along the surgical spectrum, low, medium, high, and prohibitive, we've demonstrated that TAVR and surgical valve replacement are generally equivalent strategies, with regard to both durability of the valve prosthetic, as well as the safety of the procedures. Now, certainly in patients who are considered at a high risk for surgery or prohibitive risk for surgery, a TAVR will be a safer option, and that's the preferred strategy. In patients who are at a low or even an intermediate risk for surgery, at Cleveland Clinic, our results are relatively similar with regard to the safety of either of these procedures.

The decision for what's the best option or best pathway of treatment for a patient is based on very specific anatomic considerations. Especially in the patient who is younger or at low risk for surgery, we want to look at not only how safe is the TAVR procedure or how safe is a surgical procedure, but also what can we do in the future. As Dr. Lou mentioned, the surgical valve or the TAVR valve, when their bioprosthetic, are going to have a lifespan of anywhere between 10 and 15 years. When that valve fails, we want to know that we can place another valve inside of it with a TAVR because it would make more sense for a patient who's, let's say around 70 years old, to have a more invasive procedure if necessary when they're younger, rather than when they're older. If that young or low-risk surgery patient can have a TAVR both now and a TAVR inside of that TAVR 10 years or 15 years down the road, then that's a very suitable patient to have a TAVR when they're low-risk or younger.

I have a question here about what can you do if you have a TAVR that has failed? There are a number of different ways in which surgical valves or transcatheter valves can fail. I'll speak from the transcatheter perspective and Dr. Lou, if you can mention from the surgical perspective. If there's a TAVR that has failed, it can either be because the leaflets or the mobile parts of the valve itself are no longer working properly, either causing bioprosthetic valve stenosis or regurgitation.

In those situations, often, we can place another TAVR inside. But again, that's an analysis we have to make based on CT scans and other imaging tests. Again, we're going to consider “what is the age of the patient” and “is it the best thing for them to have another TAV-in-TAV,” as we call it at the current time. Or are they better suited to having that TAVR taken out, having a surgical valve replacement, and then considering a valve in valve TAVR in the future? There are also scenarios where the TAVR can be leaking outside of the valve frame, and those require different treatment strategies, which are often again, transcatheter or percutaneously addressed. Dr. Lou, I'd like to turn to you. How would you deal with a surgical valve or a transcatheter valve that's failing? What are your thoughts?

Xiaoying Lou, MD:

We experience that a lot here because we get patients who have had these complicated cases done at some other centers or even here, wherever, and they failed over time, or they get infected. That's another reason for those valves failing as well. We get a lot of these patients who come in and they've had prior surgeries or prior TAVRs. It really is a heart team discussion also. I think that's a big part of this, and it's very much dependent on the individual patient. We really look at the patient, their risk factors, what is their tolerance for getting open heart surgery, their age, all of those comorbidities that factor in. We try to make a decision from a heart team approach about what will be the best to offer durability and something that's safe for that individual patient.

I would say someone who's probably in their late 80s who comes in and they've had a prior prosthetic valve that is failing now and it's not infected, then TAVR is a really good option for those patients. Otherwise, if it's a younger patient or the valve is infected, TAVR doesn't take care of the infection. If there is an infected valve, that's the cause of the failure. We do have to, I think, move towards the open heart surgery approach to take out that valve and accept the risks of that operation, and just do our very best for that patient to get them through. But the TAVR would not address the infection, and we do see that a lot unfortunately with very tough cases.

Amar Krishnaswamy, MD:

Absolutely. Very helpful. Finally, to close out, I think I mentioned just briefly, how long do TAVRs last. For the most part, based on the testing that was necessary for these valves to be approved, as well as the clinical experience that we've had over time, there's a relative similarity between the durability of a surgical aortic valve replacement and that of a transcatheter aortic valve replacement. Generally, we're looking at approximately a 10-to-15-year durability, again, with options for treatment when the valves fail, as we've discussed.

Thanks again to Dr. Harb from cardiac imaging, Dr. Malas from cardiac surgery, Dr. Lou from cardiac surgery. To those of you watching, we appreciate your time. Take care.

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