Intro: Welcome to UAB MedCast, a continuing education podcast for medical professionals, providing knowledge that is moving medicine forward. Here's Melanie Cole.

Melanie Cole, MS (Host): Welcome to UAB MedCast. I'm Melanie Cole. And joining me today is Dr. Panayotis Vardas. He's a cardiac surgeon and Assistant Professor at UAB Medicine, and he's here to highlight mitral valve repair and surgery. Dr. Vardas, thank you so much for joining us today. As we get into this topic and before we talk about repair and surgery, can you just speak a little bit about degenerative mitral valve disease and what you've been seeing in the trends?

Dr Panayotis Vardas: Absolutely. First of all, thank you very much for having me back, Melanie. I'm glad to be here. Before we talk about degenerative mitral disease, what is mitral regurgitation? Essentially, mitral regurgitation is a valvular abnormality. It's an abnormality of the mitral valve, which is actually affecting over 2% of the total population. So, it's very common. It's the most common valvular abnormality and has a prevalence that increases with age.

Now, within the spectrum of mitral regurgitation, there are different causes and types of mitral regurgitation. And we're talking about primary or secondary mitral regurgitation. The most common name of primary and cause of primary mitral regurgitation is degenerative mitral regurgitation. We're referring to degenerative disease or organic primary mitral regurgitation. What is the problem with the mitral valve? And to be more precise, when we're talking about the mitral valve, we don't talk about just the valve, but with the mitral valve apparatus, which anatomically involves the two leaflets, the annulus, and the subvalvular apparatus, including the papillary muscles, the chordae tendineae connect the papillary muscles to the leaflets, and the ventricular wall. But what is the prominent problem with degenerative mitral regurgitation is some structural deformity or damage that most commonly happens to the leaflets or the chorda or the papillary muscles. That results in an insufficient and leaky valve.

Secondary mitral regurgitation, also known as functional, mostly has to do with some problem of the ventricular wall, some problem of the ventricular wall motion or abnormality, for example, in ischemic heart disease after a myocardial infarction, or has something to do with the atrial chambers when those get enlarged, for example, in chronic, longstanding atrial fibrillation, to mention some of the possible causes for secondary mitral regurgitation.

Melanie Cole, MS: Thank you so much for that, Dr. Vardas. So now, I'd like you to speak a little bit about guidelines and indications for surgical intervention. Where in the continuum of symptoms, and I'd like you to speak about symptoms and ventricular dysfunction, does that discussion of a surgical intervention come into play?

Dr Panayotis Vardas: Absolutely. So, going back to degenerative mitral regurgitation that we initially talked about, this is something that is unique with regards this disease process. Their recommendations and the guidelines talking about when the patients should look and seek help from a surgeon. And the reason of this is because after successful mitral valve repair, we're probably going to talk about this, the long-term survival following a successful mitral valve repair for degenerative mitral regurgitation is similar to age-matched controls provided that the operation is done in a timely fashion and early in the disease process.

Taking off from this base, now, the guidelines and the recommendations, they talk about when the patients should look for surgical attention. The first patient population that is very easy under the guidelines to look for a surgical repair is symptomatic patients. Patients that present with shortness of breath, fatigue, palpitations. They are patients that in the setting of degenerative mitral regurgitation, they have strong indication for mitral valve intervention.

Now, what we know is when we see the cycle of mitral regurgitation at the long-term in the ventricular function, or to be more precise, left ventricular systolic dysfunction, it might be more advanced. The disease process becomes more tricky when these patients come for repair. And the guidelines, they have established strong recommendations for this specific patient population. So for asymptomatic patients, but with significant LV dysfunction, when we're talking about this, we're looking at the ejection fraction, should be less than 60%, or the ventricle is dilated in end-systole more than 40 millimeters, and have severe primary mitral regurgitation, mitral valve surgery is recommended.

Also, mitral valve surgery is recommended for patients that they are asymptomatic, and they don't have LV dysfunction, left ventricular dysfunction; however, the anatomical consideration of the specific valve gives a likelihood of a successful repair without residual mitral regurgitation, which is greater than 95% and with an expected mortality of the surgery of less than 1% in a center of excellence, those patients should be considered for early surgery, although non-symptomatic.

Melanie Cole, MS: Dr. Vardas, and this is such an exciting time in your field, I'd like you to speak about the repair itself. What's exciting? What is really a game changer in your opinion? And when you're deciding between repair versus replacement, what of those advancements comes into play?

Dr Panayotis Vardas: So, Melanie, for degenerative mitral regurgitation, the standard of care is repair. Mitral valve repair has been reported in Center of Excellence of 95% freedom from re-operation at 15 years out from the surgery. This is very important if you consider that, again, this kind of surgery replenish normal expectancy of life of this patient.

So, when we look at the mitral valve, that is a leaky mitral valve, we're looking at what the valve pathology, we're talking about primary pathology. Degenerative mitral regurgitation, our goal is always to repair the valve and to not leave the operating room with more than mild mitral regurgitation after repair.

Now, if the pathology of the valve is not primary but secondary or, for example, rheumatic disease, infectious disease like endocarditis, in those times, we're looking for mitral valve replacement. A lot of these patients, they don't have anatomy suitable for repair. And based on recent data, we know that for these kind of subcategories of patients, For example, rheumatic patients, those repairs, they are not durable, and we're looking for one-time shot, one operation.

Now, for very few situations where degenerative mitral regurgitation is so advanced disease and you cannot get a durable repair, replacement is a consideration as far as you make sure you preserve the chorda of the valve. And what that does is essentially helps with LV remodeling after the mitral valve replacement. So, in that case, we're talking about chordal-sparing mitral valve replacement.

Melanie Cole, MS: Dr. Vardas, can you discuss, as you're discussing mitral valve repair and replacement, the importance of having a robust care team when treating mitral valve disease and how the utilization of the multidisciplinary team has been ideal for managing these patients?

Dr Panayotis Vardas: It's absolutely, in the modern era of medicine, necessary through thorough and comprehensive care of this specific patients to have the heart team approach. In fact, in the current guidelines and recommendations, heart team approach to viral disease is always class one and the top recommendation in those tables. Heart team approach means you have a cardiologist, a structuralist, and a surgeon that will look together into the specific patient to the specific disease process. They analyze together the data, including the transesophageal echocardiogram, the angiogram, the right heart catheterization and all of the above, and they make a comprehensive plan what's the best treatment option for this specific patient. You see the patient in the operating room, but in the long term, those patients, they see a cardiologist, they have seen a cardiologist, they will be seeing a cardiologist. We follow our mitral valve repairs along with the cardiologists. But for the best outcome for the best outcome of every mitral regurgitation, a comprehensive heart team approach is necessary because mitral regurgitation is tricky to understand the etiology. And when that changes from degenerative into functional or ischemic, the treatment options change and the recommendations change. So, that's why it's important to have a 360-degree approach to this problem as a heart team.

Melanie Cole, MS: Dr. Vardas, this is such an interesting interview and I thank you for joining us. As we get ready to wrap up, what are the conditions under which you believe patients would benefit most from your incredible experience and expertise and these procedures we're discussing here today?

Dr Panayotis Vardas: So, first of all, mitral valve repair comes in different tastes. The father of mitral valve repair was Alain Carpentier from France, where he first figured out that those valves get repaired, the patient that will live a normal expectancy of life, and came up with a French correction. Many evolutionary techniques has happened since that moment, but the principles are the same. Along with those techniques, technology has evolved and, in the same way, has evolved also surgery. The principles also stay the same.

So, right now, we're talking about doing the traditional mitral valve repair with French correction principles through a sternotomy approach, through a minimally invasive robotic approach, through a thoracotomy approach. And what is coming more and more is the transcatheter technology and transcatheter repairs that right now there are so many trials going on for different devices that they address annular dilatation to rupture chordae to transcatheter mitral valve replacements.

And many of these trials are available here at UAB for patients. They are all very high surgical risk, or sometimes the anatomical consideration of the specific valve, they are such that a transcatheter approach are more suitable. And some transcatheter replacement is more suitable than a surgical valve. For example, in a very extensive mitral annular calcification, when the risk of the procedure is high, we have transcatheter valves in international trials that we can provide to our patients to deal with their mitral valve regurgitation or sometimes associated to the mitral valve stenosis. And this is an exciting moment for our specialty, because the heart team approach again between cardiologists, structuralists, and cardiac surgeons, we all work together and we embrace technology and work for the best solution for our patients.

Melanie Cole, MS: Thank you so much, Dr. Vardas, for joining us again. And for more information, please visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. I'm Melanie Cole. Thanks so much for joining us today.