Transcription:
Aortic Stenosis and TAVR

Prakash Chandran (Host):  Chances are you know someone or have a family member that was diagnosed with aortic stenosis. Just a decade ago, the only treatment for severe aortic stenosis in patients was open heart surgery. Today there is a less invasive procedure called transcatheter aortic valve replacement or TAVR for short. We’re going to learn about it today with Dr. Farhan Ali, medical director of interventional cardiology at Baylor Scott & White Heart and Vascular Hospital in Fort Worth on the campus of Baylor Scott & White All Saints Medical Center Forth Worth. This is Heart’s Beat with Baylor Scott & White Heart and Vascular in Dallas and in Forth Worth.  I'm Prakash Chandran. So first of all Dr. Ali, it’s good to have you here today. What exactly is aortic stenosis?

Farhan Ali MD, MA, MPH, FACC, FSCAI, RPVI (Guest):  Aortic stenosis is a very, very common disorder of the main valve of the heart. If you think about the heart in general, the heart is a pump. It pumps in one direction and it supplies the oxygen and nutrients to all the organs—the brain, the heart itself, the liver, spleen, kidneys, etcetera and all of your muscles. So the valves allow the pumping of the blood to flow in one direction. So we can have problems with these valves that then impede the function of the heart. So, for example, if the aortic valve has leaking then you're going to get an inefficient function of the pump, the heart. The valve can also get blockage or stenosis. That’s what we’re talking about today. That can really prevent the blood from reaching the target organs like the brain, the other organs, and cause a lot of symptoms and problems that patients then experience.

Host:  So who exactly develops aortic stenosis and what symptoms might they experience?

Dr. Ali: So the predominant type of blockage takes years to develop. It doesn’t happen overnight. So most of these patients that have aortic stenosis are over 65 years old. It’s estimated that 12% of the population over 65 have aortic stenosis. That being said, the baby boomers are turning 65 at a rate of almost 8,000 per day for the next 15 years or so. So there’s a large population that is at risk for having this disease. The symptoms that you get with aortic stenosis, what people can expect to have, is severe shortness of breath with minimal exertion. Walking 50 yards puts you out of breath, you feel like you’ve run a marathon. Getting chest pressure, tightness, pain, discomfort with doing minimal activity or even rest. Then at some patients even passing out. They just pass out for no reason. They black out or they pass out, they fall. That can also be a symptom of aortic stenosis. You can have symptoms of heart failure, leg swelling, difficulty breathing while laying down. So this, you can imagine, can really inhibit somebody’s daily activities or their basic life functions can be really hindered with this.

Host:  So tell us a little bit about how aortic stenosis was treated in the past.

Dr. Ali: The aortic stenosis, as you mentioned, for the last half century prior to a decade ago, the treatment for aortic stenosis has predominately been open heart surgery with valve replacement either with a mechanical metal valve or with a tissue valve derived from either pig or cow tissue. The surgery was really a pretty big deal. It’s a four or five hour surgery. It involves opening up the chest. It involves having a breathing tube placed and recovery of four to five days in the hospital plus an additional one month recovery where you're going to physical rehab afterwards and kind of getting your strength back. So it takes a lot of time out of the patient’s life. It effects the productivity of that patient if they're working or if they have a job. So it’s sort of a big ordeal. That being said, surgery has been the gold standard for half a century. The risk of major complications including death, stroke, and bleeding for open heart surgery have been relatively low. So it’s been a good procedure while we’ve had it. It’s still available and it’s still very, very useful and it’s not going away because we now have TAVR, which is a new option.

Host:  So let’s get into that relatively new option right now, TAVR. Tell us a little bit more about what it is and how it’s different from the traditional method.

Dr. Ali: Transcatheter aortic valve replacement, or TAVR for short, is a catheter based procedure. It’s done in the same way that we do coronary stinting or stint procedures. So I'm an interventional cardiologist. What I do is when people are having heart attacks where they have a blockage in their arteries or they have a blockage that’s causing them symptoms of chest pain, we typically go in through the groin or through the wrist, through an artery, and reach the heart through a catheter. Under x-ray we can then fix those problems with stints or balloon angioplasty. The aortic valve can similarly be reached from the groin with a minimally invasive needlestick, not even with a knife or a blade to get in. So there no real surgical approach to the heart that way. We’re not cutting anybody open. We basically go in through a catheter and deliver a valve under x-ray and then deploy that valve in position, pushing the old valve to the side and basically leaving a new valve that is working and functioning well, and then get out. That procedure can take really about 30 minutes.

Host:  That is truly fascinating. So it takes 30 minutes. You don’t really have to make a major incision. I've heard that the recovery time is much faster. Like patients can go home the next day. Is that true?

Dr. Ali: That is true. So in a lot of patients, we don’t actually necessarily need to put them under full anesthesia. We can do what’s called conscious sedation. We put them under a mask. They're basically kept very, very comfortable. We go and do the procedure and then wake them up immediately after the procedure. They're awake maybe 15 minutes after, 10 minutes after. The most amazing part about this procedure is the immediate impact, the immediate benefit that the patient feels after the valve is placed. We’re putting a new valve in reducing a severe blockage. The patient feels it immediately. They're not as short of breath. They're not having as much chest pain. They're not having symptoms and they feel like they can do anything at that point.

Host:  So it certainly seems like if the option is there that most people would want to do this new TAVR method versus the old traditional one. So I'm curious as to what type of patient is typically a good patient for this.

Dr. Ali: So in 2012, TAVR—the catheter based valve replacement option—because commercially available for the first time. The caveat there was that it was only available for very high risk patients—high risk meaning that they had an 8% chance of death having surgical replacement for this valve. So that started at very few centers and sites throughout the United States and basically patients be limited to that. So if you had severe aortic stenosis, you would go through a valve team or a valve committee comprised of cardiothoracic surgeons, interventional cardiologists, and an entire team of people that would look at your case and go, “You're a high risk surgical patient. You don’t meet the criteria for surgery, and you might be a candidate for TAVR.” Then you go through a workup for whether or not you can get it. If you fast forward to 2016, the FDA then approved intermediate risk. Intermediate risk patients are patients that have a 4 to 8% chance of dying during an open heart surgery to replace the valve. The intermediate and high risk patients comprised of about 20% of the total population of patients that have aortic stenosis. So it’s really just the tip of the iceberg.

What’s exciting about TAVR, which really is a fascinating train if you consider the timeline—is that the low risk indication just got approved this August in 2019. Low risk patients are patients that have an expected mortality of 4%. The risk of dying during open heart surgery is less than 4%. So to put that in perspective, the people that would benefit from TAVR if you look at the three categories—the high risk, intermediate risk, and low risk. If we put it in examples, a high risk or intermediate risk patient would be somebody who would be over 80 years old who would have already had open heart surgery maybe five/ten years ago. So they’ve already had their chest cut open once. Maybe they have other medical problems like they have severe COPD or lung problems from years of smoking. Maybe they have kidney problems and they're on dialysis. So if they have all of these complications, other medical problems coupled with an older age then that puts them in an intermediate risk to high risk category and those patients would benefit from TAVR. Again, going through a process where they have to meet with two surgeons, an interventional cardiologist, and kind of determine what their risk category is and then go from there.

The low risk patient is somebody would be, for example, maybe 70 years old, has no other medical problems. They don’t have diabetes necessarily. They don’t have hypertension or other problems, but maybe they have isolated aortic stenosis and they're now feeling those symptoms. Those patients in the past did not have any option for TAVR. They were only allowed to get open heart surgery and that was sort of the end of it. With the new FDA approval and guideline changes recently, now those patients are all candidates for TAVR.

Host:  Yeah. It’s truly amazing to hear how fast things have moved in the course of really just seven years, which kind of is unheard of with the FDA. It really speaks to the effectiveness of TAVR as a treatment. Now, as you mentioned, it’s just so much more accessible to people who really didn’t have that option before, even the low risk patients. Still, it feels like assessment is a really important thing. I understand that at the valve disorder center in Fort Worth that you have a multidisciplinary approach to assessing the appropriate treatment options. So I'm curious as to team members who take part in this assessment and how the whole process works.

Dr. Ali: There are what we call implanters of the valve. Those are typically the interventional cardiologists who do catheter based procedures. Typically there are four or five or those physicians that do the procedure. Then there are cardiothoracic surgeons that do the open heart aortic valve replacement. There are typically three or four of those physicians as well. They all meet on a weekly basis and we discuss the patients that have severe aortic stenosis and we discuss the category they're in. Are they in high risk, intermediate risk, low risk? What does their anatomy look like? You know there’s a whole host of things that a patient can expect to have done if they decide that they're going to get treatment for their aortic stenosis, and they get referred to a valve program like this.

One of the things they do first is they meet with a surgeon, they meet with the interventional cardiologist, they get physical exams from these physicians. Then they get a whole host of imaging tests. They usually get a CT scan to measure their aortic valve, their aorta, and to measure their access sites meaning the iliac arteries—the arteries that we enter from the groin—to make sure that they don’t have blockages in those arteries and that they don’t have issues to deliver the catheter to the heart. Then they have lung testing and other types of testing to make sure that we can get an appropriate measurement for them in terms of a specific valve size for that patient and a specific valve type. Once that happens then the patient is determined to—In a multidisciplinary approach, the team sort of tries to decide what is going to be the best interest of that patient long term, short term, and what are the patient preferences. Those are also very important.

Host:  Yes, it certainly is. It’s amazing that you have that multidisciplinary team to evaluate things on a case by case basis. Just in wrapping up here, what should patients and their physicians or cardiologists look for in a program that offers TAVR? What makes a good quality program?

Dr. Ali: A good quality program is going to have a pretty transparent process. They're going to have their mortality data that’s publicly available meaning how many patients die per percentage of patients that die in that program. It’s going to have a number of outcomes data that they can present. You're going to want to have a program that does a high volume of these procedures so that the experience level is going to be very good. You're going to want a program that has a different—this is my opinion—a program that might have multiple operators rather than a program that only has one operator or two operators. Because then you have a more diverse committee that is meeting and pushing back and forth ideas of pros and cons as to proceeding with a TAVR procedure.

Host:  Okay, that’s helpful. Is there anything else that you want to share with our audience before we close today?

Dr. Ali: I would just say that out of all the cardiac procedures that I do, TAVR is probably my most favorite procedure because I think it’s the most rewarding and has the most immediate impact for patients. The change in their quality of life is immediate. It’s an immediate gratification for the physician and the team that performs that procedure. It’s immediately noticeable to the patient.

Host:  Alright Dr. Ali. Truly appreciate your time today. That’s Dr. Farhan Ali, medial director of interventional cardiology at Baylor Scott & White Heart and Vascular Hospital in Fort Worth. Thanks for checking out this episode of Heart Speak. To find a specialist on the medical staff at Baylor Scott & White Heart and Vascular Hospital in Fort Worth or Dallas, please call 844-279-3627 or visit baylorhearthospital.com. If you found this podcast helpful, please share it on your social channels and be sure to check out the entire podcast library for topics of interest to you. Thanks and we’ll talk next time. Baylor Scott and White Heart and Vascular hospital Dallas and Fort Worth - joint ownership with physicians.