Aortic Valve Repair for Aortic Regurgitation

Podcast Transcript

Announcer:

Welcome to Cardiac Consult, brought to you by the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic. This podcast will explore the latest innovations, medical and surgical treatments, diagnostic testing, research, technology and practice improvements.

Lars Svensson, MD, PhD:

Hello. I'm Lars Svensson, and I'm here with Milind Desai. The topic for discussion today is aortic valve regurgitation. Milind is an expert on this. He's done a lot of research on the imaging for aortic valve regurgitation and the aortic root, apart from his many other areas of expertise, like running many trials on cardiomyopathies. The big first question is, what is aortic valve regurgitation, and why is it important to both detect it and treat it, Milind?

Milind Desai, MD, MBA:

Thank you very much for having me. Yes, the aortic valve is one of the four key valves within the heart. It serves as a conduit between the heart and the aorta where the blood gets pumped out. Aortic valve regurgitation is defined when the blood, instead of going forward into the aorta and rest of the body, some of it leaks back. It regurgitates back. The spectrum could be mild to severe. As one can imagine, the more the extent of the regurgitation, the more the heart faces excess volume. If left over time, that results in a chronic state of volume overload, which then results in congestive heart failure, symptoms, et cetera. If left untreated, death.

This is the most common natural history of aortic regurgitation, meaning it happens over a period of time with some chronicity. If this leakage were to happen acutely because of some catastrophic infection or dissection, then it causes what we call acute aortic regurgitation, which often results in acute heart failure and becomes pretty much almost an acute surgical emergency. It can present in multiple flavors, but essentially, the bottom line is that it exposes the heart to excess volume.

Lars Svensson, MD, PhD:

Great. If a patient hasn't seen their doctor and the doctor doesn't hear a murmur, which is very characteristic of a leaking valve, what symptoms do you think patients most frequently present with, and what should they be thinking about if they have new symptoms or something?

Milind Desai, MD, MBA:

You are absolutely right. Aortic insufficiency, aortic regurgitation murmur often tends to be not as evident. Often we have to move the patients, adjust their position, lean forward and listen carefully in the right location to hear a blowing murmur, and it is very often missed. The problem with aortic insufficiency is it’s one of the lesions where it can progress over years without having symptoms. The most common presentation is the patients get an echocardiogram where we identify the leak.

Occasionally, patients may present with symptoms, following which we do investigations that result in the diagnosis. What are the symptoms? The most common symptom is shortness of breath or effort intolerance. “I was able to hike a couple of mountains. Now I can barely do that.” Or once the disease gets advanced, you may present with overt symptoms of congestive heart failure, including swelling in the legs or not being able to lie flat at night, et cetera. But the most common presentation I've seen with aortic insufficiency is they are going around their lives without any major symptoms, and then they may have some effort intolerance.

Lars Svensson, MD, PhD:

What about their relationship with palpitations? How often do you see that, or for that matter, chest pain, if ever?

Milind Desai, MD, MBA:

Chest heaviness is not uncommonly seen in the context of aortic insufficiency. What happens is these patients, basically their heart tends to get dilated, and there is remodeling of the heart with the mass getting increased. So, they do present with some chest heaviness. Often, patients get worried that they're having a heart attack or anginal pain. Then, when we go looking for that, is when we stumble upon aortic regurgitation. Again, with the remodeling of the heart, it is not unusual to see excessive palpitations. PVCs are not uncommon.

Lars Svensson, MD, PhD:

Yes, whereas with the mitral valve, when it's leaking, atrial fibrillation is a common consequence long-term. With the aortic valve, that is typically not the case, but palpitations of various types do occur. All right. As a cardiologist, when you have a patient visit, what are the things that you're looking for when you see the patient that may suggest that the patient has severe aortic valve regurgitation?

Milind Desai, MD, MBA:

Again, after a good history, often they end up at a place like Cleveland Clinic because somebody's found something. But beyond history and EKG, obviously, echocardiography is the mainstay. A well done echocardiogram will help us understand what is the etiology of the leak? Is there something wrong with the valve? And then what is its impact on the heart? So, if it is leaking, how bad is it leaking? And when it's leaking bad, what is it doing to the heart chamber, the left ventricular chamber size? Down the road, also what we are looking for is ejection fraction, or the pumping chamber function, contractility of the heart. Advanced cases may also have other changes within the heart, including the right side of the heart.

The other piece we are very commonly looking for is what is causing it? It could be a problem with the valve, where it could be a bicuspid valve or a trileaflet valve with a hole, what we call fenestrations. Sometimes it is very commonly seen in the context of an aortic aneurysm. Your proximal aorta, close to the heart is dilated, and it may stretch the valve like a balloon, causing a leak. Is it a primary valve problem? Is it an aorta problem? Is it a combination problem? So, these are some of the things we are looking for.

Occasionally, the valve leak may not be straightforward, and we may have to do additional testing. Sometimes we end up doing what is called a transesophageal echo to further characterize the degree and the etiology of the leak. Frequently, we will also do cardiac MRI to precisely quantify heart size and heart function. Of course, I strongly believe that if you have a patient with a bicuspid aortic valve that could cause aortic insufficiency, everybody should have at least one tomographic scan. We do commonly gated contrast CT to measure the aortic size so that we are capturing the full picture.

Lars Svensson, MD, PhD:

Yeah, great. We get into the imaging, but a couple of things that your cardiologist might look for. One of the things with a leaking valve is that you often have a high systolic blood pressure, so that's the higher blood pressure, and a low diastolic blood pressure because your heart's pumping out a lot of volume of blood, and then it drops down again. The consequences of that in advanced cases, people can have some head nodding. If you look at your vascular bed under your fingernail, you have what was called Quincke's sign. You can see the pulse in your finger. One of the interesting ones, if you cross your legs, your leg may bounce a bit more. It has been said that one of the reasons people thought that Abraham Lincoln may have had Marfan's syndrome and maybe also a leaking valve was that in the pictures, his foot is blurred in the photographs, suggesting it was moving at the time of the photograph. Obviously, exposures were longer at that time.

Basically, the most important thing is the echo finding with a severe leaking valve with a big left ventricle is typical and also the findings of maybe a reduced ejection fraction as you mentioned. What about some of the more advanced things that you may be looking for on the echo for? For example, are you looking for scar tissue on MRI? When do you go ask patients and recommend that? What about the new things that you've been studying, which is strain, which is the degree of muscle strain in the left ventricle? Where does that fit into assessment for the patient?

Milind Desai, MD, MBA:

So, the utility of these situations is not in a symptomatic person with an overt disease. The utility, in my opinion, is to time precisely an operation in an asymptomatic person before it gets to an irreversible point of damage. One of the things you mentioned is strain assessment on echocardiography. Ejection fraction is a cruder measure of heart function. Strain measures regional heart function and is thought to be a little bit more accurate. In a publication that we did, we took all patients with significant aortic insufficiency and preserved heart function. We were still able to identify patients with lower strain or more abnormal strain who did worse. We occasionally use that. We occasionally use BNP, which is a blood marker to help time surgery.

Now, the scar quantification in MRI. A lot of cardiomyopathies and valvular disease also, once it reaches to an advanced stage, it characterizes as cardiomyopathy. There may be deposition of collagen or some fibrosis formation that we can not only image, but precisely quantify. There is emerging data that the higher scar content you have in your heart muscle measured on MRI, the worse your long-term outcome. These are all adjunctive markers of potential badness if present.

Lars Svensson, MD, PhD:

So by implication, if there's scar tissue on the left ventricle, then there's more risk of chronic heart failure. One of the things that we're looking for is intervening before chronic scar tissue develops.

Let me ask you, when do you decide in patients with a leaking valve that you've picked up clinically, maybe on echo, to do, if they're asymptomatic, some type of stress test? And what's your favorite stress test to see if you can physiologically determine how severe the regurgitation is? And when do you go and say, for example, get a CAT scan? Because we know a lot of these valves that are leaking, it's related to enlargement of the aortic root, the leaflets have pulled apart, and sometimes the patients have connective tissue disorders. What do you do about those two groups of patients?

Milind Desai, MD, MBA:

So, the first scenario of when I consider doing a stress test: If a person comes to my office and says they are totally asymptomatic, if I see significant valve leak and very significantly dilated heart, under those circumstances, I'm going to strongly recommend surgery. But there will be some folks who are still not convinced about surgery, who still are on the fence. They cannot fathom the concept of having an operation in an asymptomatic state. Sometimes those patients, we would put them on a treadmill. To me, being asymptomatic is a starting point for negotiations. You are going to have to prove it to me on a treadmill. Most commonly we do stress echocardiogram. That way, we can not only understand the exercise capacity and what the arrhythmia burden is on the treadmill, we can look at the ECG. But at peak exercise, we look at how the heart is responding. Is the heart chamber appropriately contracting with high exercise, with high adrenaline? Or is it sluggish?

Sometimes it may get worse and the patient may get asymptomatic. Or the patient may get very symptomatic. Or the patient may not be as good in terms of their excess capacity as they think they are. With regards to the CAT scan, as we discussed, if you have a bicuspid valve or if you are suspecting connective tissue disease where you are suspecting there is aneurysm of the ascending aorta or the thoracic aorta, CAT scan serves a very, very useful purpose in identifying not only concomitant aortopathy, but also if that is what is driving the leak, meaning stretch of a balloon.

The other thing where CAT scan is pretty much the gold standard is it may even help us plan for a procedure if we are moving along that line. If you see a fair bit of calcium on the aortic valve, that may point me towards this may not be a repairable situation. If we see that the annulus, which is just underneath the valve, the structure, if it is massively enlarged, then that may drive me towards a different thought process, or rather it would force me to have a conversation with the surgeon about, do we need to do something differently there? So, CAT scan, it provides us value in terms of aortic dimensions, but also looking at the valve and the perivalvular structures.

Lars Svensson, MD, PhD:

All right. So, you've seen the patient, the patient has severe aortic valve regurgitation. For the sake of this discussion, we won't go into all the coronary imaging, but we obviously get cardiac catheterizations here at the Cleveland Clinic because we've seen patients with coronary artery disease that have been missed on the CTAs or CAT scans, and so we still use cardiac catheterization on everybody.

What are you advising your patients? Let's bring in, you talked about calcium on the leaflets, which means that the valves are less likely to be repairable. But what are you saying to patients based on age, and what are you saying or talking to them about as far as valve types? Let's say the ideal is obviously a repair. But if not, what kind of valve discussion do you have with patients? In other words, what type of prosthesis?

Milind Desai, MD, MBA:

The business of shared decision making is real, especially at a high-volume place like the Cleveland Clinic, where patients come from all over the world, patients are very well-educated. They know exactly the nuances of different things. To me, the fundamental first question I ask is, can we save the valve? If that is the case, then the benefits of having a native valve far outweigh anything. Nature-made is far better than a human-made valve, in terms of what I recommend.

Especially if the person is younger, and especially if it's a younger female, where menstruation, childbearing, all those things are at play. But younger folks with their lifestyle, et cetera, they also are loath to long-term blood thinning. We will talk about what's a reasonably ideal candidate for a repair. But if there are no red flags against repair, then that's what I am discussing with them.

But the best laid intentions sometimes may not go as planned. It is always important when we are talking to them in the preoperative area to have a backup plan. If the repair does not work, are you going to get a mechanical valve? Are you going to get a bioprosthetic valve? In some situations, with an infection, et cetera, we may talk about a homograft, et cetera. But typically the conversation is mechanical or bioprosthesis. That generally boils down to age.

The guidelines recommend anybody up to 65 consider a mechanical valve. But at the Cleveland Clinic, as we know and practice, we have long been advocates of a bioprosthesis in patients as early as in their 50s and beyond. The advantages of a bioprosthesis is that you don't need blood thinners in the long term. The disadvantage, obviously, is a 10 to 15 year lifespan of that bioprosthetic valve.

The flip side is a mechanical valve, which typically we recommend in younger individuals. The disadvantage is lifelong anticoagulation, but with the newer type valves, like the On-X valve, for instance, the burden of anticoagulation is not as bad as it is with the older generation valve. You can get away with the Coumadin ratio of around two, INR of around two instead of two and a half to three. These are the conversations. Of course, if there's a younger person who's got a high-risk job, like a sheet metal worker or a construction person, then we discuss and share decision-making about not putting in a mechanical valve.

Another important thing that in the last few years it has gotten very much part of our discussion is discussing lifetime management of aortic valve disease, because patients are living longer. If you get a valve that's only going to last 10 or 15 years and you are only 55, then you have to plan for the patient to be living till they're 85. These nuanced conversations always happen.

The good news is a well-done repair by an experienced surgeon at a high-volume clinical place like Cleveland Clinic, the long-term outcomes are excellent, sometimes even better than a bioprosthesis.

Lars, I wanted to ask you about that. When I hand over the patient to you, what do you talk to them about, and how do you decide this is a good repair candidate? What is it that you tell them about the longevity? What are the things that you say, "This is a red flag, I may be 50/50," et cetera.

Lars Svensson, MD, PhD:

Let me go just back to a couple of points you made with mechanical valves. It is true with the On-X valve, it has been approved to run at a lower, what we call INR, which is the measure of the anticoagulant Coumadin and its effect. Unfortunately, we ran a big prospective randomized trial, trying Coumadin versus the new anticoagulants like Eliquis, and the stroke rate was higher in the patients who had the new anticoagulant. So, Coumadin is still the standard of care for mechanical valves. They don't wear out. The long-term results are very good, but the downside is the risk of bleeding. Obviously in patients who are very active, people who love being [active], let's say, downhill skiers or racing motorbikes, et cetera, et cetera, or dangerous jobs, it may not be the ideal.

Now, having said that, Milind touched on lifetime management of your valve. With the biological valves, the new ones, they seem to be really good. I'm going to be presenting in a couple of months' time, the 10-year outcomes for one of the new valves that we used in 689 patients for a prospective study as part of FDA approval. The results are looking very good in that valve. That’s a valve we deliberately used more often in young patients, and it seems to be holding up very well. I don't have the final analysis yet, but we will be getting that. That’s going to be very interesting because we're going to compare it with the gold standard, which was the Carpentier Edwards Model 2700 valve, which we put in about 19.5 thousand of them here at the Cleveland Clinic. We're going to have a very good comparison.

The other thing, since 2010 at the Cleveland Clinic, the results of a re-operation on a biological aortic valve are the same as the first operation. In other words, there's no penalty for needing another operation. When it came to valves we had repaired, when we looked at this a few years ago, and we're doing it again, we had no deaths in patients who had aortic valve repair and needed another operation down the road. Depending on age, one option is a biological valve, a repeat biological valve, and then later a TAVR, so called valve-in-valve. What we really do a lot here at Cleveland Clinic now, and we're up to 11% of patients, we will enlarge the aortic annulus, which is where the valve sits and put as big a valve in as possible with the idea that that's a better seating size for a valve-in-valve down the road.

Now you had touched on repairs being better than the biological valves. They actually are. We did a study a few years ago, about 10 years ago. In our patients with bicuspid valves that had repairs versus biological valves, the failure rate was the same out to 12 years. But beyond 12 years, the biological valves had a very quick drop off in durability. The biological valves, very quick drop off. The repaired valves, the curves actually flattened with less risk over time. The study that I'd like to quote for our bicuspid valve repairs, which are very common in young people, especially younger people who have leaking valves, 91% of those repairs were working 10 years after surgery. In other words, 9%, nine out of 100 had failed within 10 years. That's much better than most other valves and biological valves, and so the durability was very good. The other advantage is the risk of stroke and infection is lower with a repaired valve. In this case, as I said, the bicuspid valves, they have better results.

Now, for patients who have enlarged aortic roots, and we can do a re-implantation operation and modification that we made here at the Cleveland Clinic of the original David operation, that has superb results. In my personal experience of over 600, I haven't lost a patient doing that operation. One of my residents analyzed our 15-year data, and it was only a 4% risk of failure out of 15 years, and most of those were related to infection. Then the other part of that is the risk of infection on the valve is much lower. You obviously don't have the risk of bleeding because you don't have to be on a blood thinner, and also the risk of stroke is much better. That's a very good operation. If a patient has enlarged roots, usually 90%, 95% of the time, I can keep and repair that valve. Again, it depends on how bad the leakage is before we operate, because sometimes, if it's really bad, the leaflets are torn to the point that we cannot keep them. So, that's a very good option.

The key things that we have to do when we do a bicuspid valve or normal three-leaflet valve repair involve multiple steps. We have to look at what's called the annulus. We have to look at the cavity where the valve sits, that's known as the sinuses. We have to look at the sinotubular junction, which is the junction between where the valve sits and the rest of the aorta. We look at the commissures, which is where the leaflets come together. All of that has to be very carefully judged and put together to make the valve work effectively. That applies both to the bicuspid valves and the three-leaflet valves.

And then we have some tricks up our sleeves to help with valves that are, for example, prolapsing, or if they have minor holes, and we can fix that. For example, use a figure of eight that addresses some of the small tears or prolapse, and that's what we believe, together with the way we do the technique here at Cleveland Clinic, which is narrowing down the annulus around a sizer. It's called a Hegar sizer that we believe has contributed to the great results we're showing at 15 years after surgery.

A couple of other points about repairs. If the problem is a bicuspid valve, we virtually always use what we call a minimally invasive J incision to repair the valve, and that includes if we have to replace the aorta also. So, we don't open up the patient's whole chest. We just open up the top of the breastbone, usually about that much at the top. It's like a trap door, and we go in and then do the repair. The result is patients recover much quicker and get back to work much quicker. We say people can start driving two, three weeks after surgery instead of six weeks when we open up the patient's whole chest. For the more complicated re-implantations, usually that means we do have to open up a patient's whole chest.

As far as recovery, my impression is the patients who have repairs recover quicker. Certainly, the patients who have min-invasive procedures recover quicker. In the patients where we put in mechanical valves, they often are longer in hospital because we have to get the blood thinner working, the Coumadin working, so that takes a bit more time for recovery.

So, Milind, what about the follow-up of these patients? Any other things about recovery? And you see a lot of these patients who are asking for second opinions about the best options.

Milind Desai, MD, MBA:

So particularly related to recovery, a lot of times when the patients come to us, they're from out of town, they're anxious, et cetera. An important part is to alleviate their anxiety. What I end up telling them is you'll spend a day or two in the ICU. A lot of them are psyched out about the breathing tube. I'm saying the vast majority of you will have an extubation the same day. That relieves a lot of their thinking.

Depending upon the size of the incision, you may spend extra two, three days. If it's a small incision, maybe three to five days. If it's a larger incision in the hospital and then recover at home, again, shorter time for a smaller incision, slightly longer four to six weeks for a bigger incision. What I emphasize to patients is no matter how young you are, no matter how healthy you think you are, you should at least have cardiac rehab because that resets your clock. It gets you back to where you need to be. Rehab has been shown to be associated with better outcomes. Make sure if they're coming from out of town, then we have plans to follow up locally. We always like to see our patients periodically, annually, or sometimes every other year, but we have a co-management plan put in place.

With regards to your comment about second opinion, aortic valve regurgitation is a finesse operation. It is a finesse diagnosis that requires skills. You can often underestimate or mistime an intervention. Even when you go for an intervention, the difference between the right hands and experience and the opposite can be catastrophic, considering a lot of these patients are younger. What I recommend if I'm doing second opinions is this is something that should be done at an experienced center that has experience in clinical cardiology, imaging, as well as cardiac surgery and follow-up care, so a high-volume valve center of excellence like Cleveland Clinic.

Lars Svensson, MD, PhD:

One of the challenges with aortic valve regurgitation and assessing when patients who have surgery, particularly when they are asymptomatic, is the timing. We know that if patients go too long and develop scarring in the left ventricle based on MRI, their long-term results aren't as good. We know it's always challenging to figure out if the patients are really having symptoms or not.

So, Milind, this is your area of expertise, and I've often asked you about this, particularly in patients with mixed valve disease. I find patients with mixed valve disease – in other words, regurgitation and stenosis – are very late in getting their referrals because people underestimate the disease. What's your current thinking now on testing in patients with aortic valve disease or mixed aortic valve disease?

Milind Desai, MD, MBA:

In the current era of advanced multi-modality imaging, we are fairly liberal in our thought process as we evaluate these patients. I'll first address the person who presents with pure aortic insufficiency or aortic regurgitation. Of course, echo is absolutely the frontline where we do the quantification of aortic valve insufficiency, as well as measure EF and volumes. Of course, we also routinely report strain because we've demonstrated some incremental prognostic value in these patients.

If the degree of quantification for whatever reason does not jive with the patient's symptoms or there's eccentric jet or what have you, then we may go to transesophageal echo to further understand. We are also routinely using cardiac MRI not only to assess the regurgitant fraction of the aortic valve leak, but more for LV size, volumes and ejection fraction. In fact, the guidelines talk about the size thresholds at which you need to refer patients, asymptomatic individuals for cardiac surgery. But I must say, a lot of these guidelines are based on data that is pretty much outdated, more than two decades old in many cases and smaller series. A lot has evolved. Our surgical techniques, our ICU techniques, our imaging techniques have evolved.

So, in fact, a few years ago, we tackled this question: Can we do better? What we found, in more than 1,400 patients with significant aortic insufficiency at Cleveland Clinic, what we saw was that if we waited till the guideline recommendation of a size threshold – these were all asymptomatic individuals – if we waited till they got past the guideline-recommended size threshold, we waited too long. In fact, our thresholds were significantly lower for going to surgery, and these patients ended up doing well. The validation of our work was that this data was proven by a European cohort. Again, our findings were also validated by another large health system within the United States. Three different patient populations came to the same conclusion that we should be referring patients at a lower size threshold than what we are currently doing by guidelines. That's the concept of pure aortic insufficiency.

You are right. The mixed aortic stenosis and regurgitation, that is a complicated beast. Often, the physicians are tracking one or the other, and they forget to pay attention to the other one. We have recently published a paper on mixed aortic valve disease, where if you wait for both the lesions to get to a severe stage, then you have waited too long. Perhaps in the moderate to moderately severe aortic stenosis and moderate to moderately severe aortic insufficiency, especially if they have symptoms and other signs, I would recommend an operation. It requires very careful assessment, symptom evaluation, imaging evaluation, often multi-modality imaging evaluation.

Lars Svensson, MD, PhD:

I agree with you. Particularly in mixed valve disease, the idea to wait for either being severe is usually too late. I'm always struck by how much better patients get after mixed valve disease and having an aortic valve replacement. Obviously, replacement because of the calcification. It’s not a repairable valve, and the results are really good. I often find it interesting how symptomatic those patients may be, and yet they have moderate disease, both regurgitation and stenosis, as you pointed out.

As part of managing patients after surgery, what we do at Cleveland Clinic is that we recommend patients follow up with you, their referring doctor, seven to 10 days after surgery, and our nurse practitioners will call your office to set up those visits. Then, it's up to you if you want the patients to come back and see our cardiologists every couple of years. Usually, we recommend an echo every year or so for repairs and replacements. For replacements, I don't recommend, or for that matter repairs, surgery unless the patients develop symptoms, usually stenosis, but not always the case, or there's evidence of left ventricular dysfunction.

When it comes to patients for whom we do, say, re-implantations for root surgery, and we do 10% of the aortic root surgery now in the United States, in those patients, we recommend they have an MRI every two, three years to check the rest of the aorta. It's rare that bicuspid valves, Loeys-Dietz or Marfan patients need another operation or develop aortic dissection anywhere else, but it does happen in about 1.4% of our patients with Marfan syndrome in one study. We do like those patients to be followed long-term by you. We're always available to be contacted if there are any concerns on your part.

Thank you very much for listening to Cardiac Consult. We're always available for discussion, a second opinion. You're welcome to phone us and get opinions. Thanks again for supporting us. We really appreciate that.

Milind Desai, MD, MBA:

Thank you for joining us.

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