The Heart in 3-D: A Transcatheter Aortic Valve Implantation (TAVI) Program

In 2010, University Hospitals Case Medical Center, in Cleveland, Ohio, opened a TAVI multidisciplinary program with a dedicated staff for patients who have advanced aortic valve disease. Dr. Costa co-directs the program along with cardiothoracic surgeon Alan Markowitz, MD. We asked Dr. Costa to share his experience with the program and thoughts on this procedure.

How long have you been performing TAVI?

For the past four years, I have worked with European colleagues in order to gain exposure to this procedure. It was unofficial training before our group actually started doing the procedure in the United States. Medtronic also put together training, guided by the FDA regulations on content, observations and simulator use. This training was extensive and well done. At present, I have participated in more than 30 procedures in Europe over the past three years and more than 10 procedures at our institution in the United States. We also brought all the members of our multidisciplinary team to Europe, including the chief of anesthesia, another senior interventional cardiologist and the cardiac surgeon. There are several steps to this procedure and anesthesia is an important aspect. I felt it was crucial for my team to go to Europe and see how they are doing it.

I believe structural heart disease experience and knowledge are essential for the interventional cardiologist planning to perform TAVI. Operators will benefit from experience navigating the heart and its 3D structures. Those skills and tactile experiences are critical when you are dealing with new procedures like TAVI, because one cannot directly translate percutaneous coronary or surgical cognitive skills into valve procedures. It is a different environment. For example, I have been doing valvuloplasties and structural heart disease procedures for over 10 years. I am also a proctor for electrical mechanical mapping, the NOGA technology, which requires a very detailed navigation to the left ventricle with large catheters for stem cell therapy. I believe that having this experience with 3-D navigation into the heart and dealing with larger catheters has helped us along the way, and we have been able to apply some of the knowledge from other techniques to our work in TAVI.

Was your training on the CoreValve device only?

Yes. Before Medtronic acquired the company, we were doing these procedures with our colleagues in Europe. We have not yet participated in the Edwards Sapien valve program.

Can you describe your current program?

Our current program is truly multidisciplinary. Our heart and vascular institute is already a multidisciplinary product. Dr. Alan Markowitz is the director for the valve center. We have now integrated TAVI as a key element of that program, which includes:

• 2 cardiac surgeons;
• 2 interventional cardiologists; 
• 2 vascular surgeons;
• a non-invasive cardiologist;
• 2 imaging specialists, 1 cardiologist and 1 radiologist, for CT and MRI, and echocardiogram;
• the chief of cardiac anesthesia;
• 2 nurses;
• 2 dedicated technologists for valve preparation;
• a dedicated nurse practitioner (for patient screening and assessment, and clinic evaluation); and
• a dedicated research nurse.

It is a large group of people working together, and it actually has been very smooth, because we have worked together in other areas. People’s prior experience of working together and relationships are important in starting such programs.

The hospital made a 4 million dollar investment in a hybrid operating room where we perform our procedures. Every Wednesday, we have a meeting with the research coordinators, the nurse practitioner, the surgeons, and the interventional cardiologists to go over the cases that we are screening, and also to go over procedures and plans for the program. The program is not just about TAVI, but about hybrid procedures [such as combined percutaneous coronary intervention (PCI) and valve replacement, percutaneous transluminal angioplasty (PTA) and bypass surgery, etc.), so it is important that once you build it, it stands over and beyond TAVI. We are doing more hybrid procedures now than we have ever done in the past. We are doing more hybrid valve procedures and structural disease interventions than we did in the past.

We were fortunate that we started the program right in the hybrid OR, so we were a little bit spoiled. In Europe, most the procedures are done in cath labs. The OR standards are somewhat cumbersome, because some areas are not applicable for percutaneous technology, but on the other hand, the safety and the comfort that we have in a hybrid room for the rest of the team, anesthesia and others, I think is beneficial.

How large is your hybrid OR?

It is probably the largest room we have in the whole hospital, similar in size to a dual cath lab. Approximate dimensions are 23.5’ x 30’ (excluding the control room and sub-sterile room.) We use giant 6-screen flat panel technology from Philips with multiple screens. The anesthesiologist has his own regular screen, the tech that loads the valve has his own video screen — it is a fascinating room.

What is the most difficult part of this procedure?

I think the most difficult part of the TAVI procedure is screening; defining who will actually benefit from this technology, and particularly now, in the United States, under the auspices of the FDA’s very strict criteria. Maybe this is not a problem in Europe, where TAVI has become standard of care. But in the United States, making sure that our patient fits the standards and criteria that are set forth takes a great deal of work and time. It is a high-risk procedure, but it is not as challenging as it might be if performed carefully by a trained team. Centers of excellence must be developed to make sure patients are treated properly, given the complexity and risk of this procedure.

Are there parallels with carotid stenting in the U.S.?

There are and there are not. These patients with aortic valve disease are usually much older than carotid disease patients. They have many other co-morbidities and the risk of the open-heart surgery is much, much higher than the risk of a carotid endarterectomy. That has been the challenge for carotid stenting, to justify its value over a surgically minimally invasive procedure, given the location of the carotid and the expertise that has been developed over the years.

With the aortic valve replacement, obviously there are centers of excellence. My colleague Dr. Markowitz has had outstanding results with more complex procedures; however, this is not the average that we see from the reports of the Society of Thoracic Surgeons (STS) database. So aortic valve replacement is still a high-risk procedure within the cardiac surgery portfolio. As patients advance in age, it becomes riskier. Therefore, I think chances for a less invasive device to be part of the mainstream standard of care therapy are better than for carotid stenting.

What are potential complications for this procedure?

We must watch for vascular complications, as in any percutaneous procedure. You have to navigate through vessels and vessels have to accommodate your device. This has been minimized in our end by using a surgical cut down approach and properly screening patients. It is an area where I think we have made progress. Other areas that are still in progress include the risk of stroke. The risk today is less than it was 5 years ago, but it is still something where we can do better. The numbers are low, the outcome of patients is still good, but we could do better. Finally, maybe a more device-specific issue, is the need for a pacemaker. Some can consider it as part of a procedure, and others may consider it as a complication. This is also something that we need to understand better. These are the three main focuses for the future in terms of improving outcomes. TAVI outcomes today are already at par with those obtained with open-heart surgery, so with the next-generation devices, if we can do even better, that would be outstanding.

What about TAVI patients who also need PCI?

That’s a good point. I think it should be done in separate events, with outcomes according to an individual judgment of your patient. If you have critical left main disease plus aortic stenosis, it is a different approach for that patient versus one with severe disease in the distal circumflex vessel, where your outcome of TAVI will not be affected. What you cannot have is one procedure complicating the other, meaning hypotension complicating a stent procedure, and a small area of myocardial injury complicating your TAVI procedure. It is not yet clear what is the best approach. In the United States, we do not have the luxury of deciding; we have to treat the coronary first because of the protocols that are here. In Europe, people have done all different types of procedures, either doing all at once, doing coronary first and then valve second, or doing valve first and coronary second. It should be an anatomically-based, clinical individual decision.

What about access sites?

Naturally, the comfort zone for us and even for the whole team, is the femoral approach. There is no question about the femoral approach being a preferred route for these procedures. Limitations are usually disease and calcification. We actually have extensive experience with the right subclavian for our surgical procedures, and have reported one of the first cases of right subclavian access, which I think is a more natural position for the operator. However, radiation is a big problem, because if you use the subclavian, you are very close to the image intensifier and you pretty much embrace it. Any time you are working in the chest, with either the aortic, direct aortic or subclavian approach, we are going to have to figure out how much radiation the operator has been exposed to, particularly the neck. The femoral approach is a no-brainer; it feels like a heart cath procedure.

How does it work between the surgeons and cardiologists in terms of their presence during the procedure?

It is a team procedure, so as my colleagues are doing the cut down for the surgical procedure in the leg, I am putting the pacemaker in the neck, because we do temporary pacing during inflations. Not everybody is there from start to end, but doing the procedure itself, everyone is together. It is a dynamic process, but at least the leading physicians are involved in the procedures from the very beginning.

How long does a standard procedure take?

We can do 3-4 procedures per day. What takes the most time is the preparation for the procedure. If the room is an OR environment, it takes longer to prepare. If TAVI takes place in a cath lab environment, procedures can be done in one hour, from beginning to end, including the room preparation. The procedure itself is only 30 minutes. It is meant to be a fast procedure, so there is not much time to waste. Once you get access, you are 30 minutes away from inflating the valve.

Are there special considerations for anesthesiology?

Our room was designed by surgeons, interventional cardiologists, radiologists, and anesthesia, so it was built to provide space, comfort and logistics to each specialty. The TAVI procedure is different from a surgical procedure. Although it seems so simple on the surface, it might be complicated. We want to operate on patients where the blood pressure is elevated. Patients have to be loaded with fluids. One of the medications to treat TAVI patients is Lasix, to prevent the development of coronary congestion, so patients come to the procedure very dry. Our anesthesiologist knows that we want this patient to be fully loaded with fluids. When you release the aortic valve, usually they go hypotensive — the heart is very stiff. We also don’t want the patient to be too anti-coagulated, as they do in open-heart surgery. Patients should be extubated immediately after the procedure, which is very different from open-heart surgery and the anesthesiologist also has to consider. These are things that have to evolve. TAVI has its own uniqueness and singularities that need to be taken into account; otherwise, things can go the wrong way.

Are there things that you particularly like about the CoreValve technology?

If you ask an interventionalist, what do you like about the stent compared to balloon angioplasty, they will respond that it is dependable and it is predictable. You put in a stent, you go home, and you know that this patient is not going to close down at night. In the time of balloon angioplasty, you were always worried. In a different way, the reason we started with the CoreValve was the predictability of the device. I can reposition it, I can pull it back, I can take it out. That makes it a much more controllable, predictable procedure than the alternative, Edwards’ Sapien, which is a one-time event, and you are out.

Could you describe the pivotal Core-Valve trial you are involved with?

The CoreValve trial is sponsored by Medtronic. It is a large study and has two arms, so patients who are at extreme risk are taken to an arm of the study where there is no randomization — they all get the TAVI procedure, because they are already at extreme risk, and there is no medical therapy for those patients. There are some metrics used to identify patients that are considered to be high risk, such as the STS score more than 10, or there are additional co-morbidities. If these patients fit the anatomical criteria, they may be randomized to open-heart surgery versus TAVI. The screening process requires a CT angiogram, echocardiogram, and multiple cardiologists and surgeons to evaluate the patient. All the data is further evaluated by a national panel, which will make an independent decision outside the center as to whether the patient qualifies for the study or not. It is a very comprehensive and laborious process. But, at the end of the day, it will be very important, because we have not done any study in interventional cardiology that has been as scrutinized and as regulated as what we are doing now. I think that is going to be positive for the future of this technology.

Dr. Costa can be contacted at marco.costa@uhhospitals.org.

Disclosure: Dr. Costa reports a consulting agreement with Medtronic.