Note: Read the accompanying case at: Emergent Percutaneous Mitral Valve Repair in Cardiogenic Shock
Dr. Ahmed, can you tell us about the structural heart program at Princeton Baptist Medical Center?
The structural heart program at Princeton is a comprehensive program based around a heart team approach, which is basically the center of everything we do. That concept is very important. There is no individual. Every decision made is made by a team that includes multiple different specialists: a surgeon, an imaging specialist, an interventional cardiologist, and a general cardiologist. Everything is centered around that heart team approach for almost every patient sent to us for an evaluation, whether it is a valve, another structural procedure, or even a surgical procedure. For a program that is so young like ours, three years old, we are a very rapidly growing program. We are fortunate to have been one of the fastest growing programs in the country and probably are one of the largest comprehensive structural heart programs in the country. We are the fastest to 100 procedures of Watchman (Boston Scientific), as well as one of the fastest growing transcatheter aortic valve replacement programs (TAVR) programs — in just over 2 years we went from 0 to 500-plus TAVR procedures. Our MitraClip (Abbott Vascular) program is one of the largest in the country. On top of that, we have a number of subspecialty programs. Princeton is very well known for being minimally invasive, whether it is our surgeons or our structuralists. All our surgeons do all their surgery either through a robot or tiny incisions. We are able to do very high quality work and treat very complex disease while still maintaining a minimally invasive heart team approach. The heart team is critical.
We saw the evolution of the heart team concept with TAVR. How is it going to be important for treating mitral valve regurgitation?
If anything, it is much more important. When a patient comes in, there are a number of questions asked. The dangerous thing to do is to say, “I’ve got a patient who looks good for MitraClip. Let me just throw a clip on there.” The key is to be obsessed with outcomes, because ultimately, people doing well should be the main focus. When the patient comes in, our imaging specialist makes sure that patient has a leak and quantifies it. Then the question is, there is a leak, but is the MitraClip really the right thing to do? It’s wonderful to have the option of a big robotic mitral valve surgery program and a MitraClip program, and be participating in various clinical trials. When we see a mitral patient, we are not just trying to fit them for the MitraClip. It is often the best treatment, but sometimes it is not. We can tell patients they are going to be seen by a surgeon that does nothing but mitral valve repair, Dr. Clifton Lewis. He is one of the country’s highest volume mitral valve repair specialists and ranks in the world’s top volume for robotic mitral valve surgery. Our patients see a surgeon who truly knows if the valve can be fixed surgically, or not, and then I can address whether the patient is an appropriate candidate for percutaneous mitral valve repair. We sit down, look at the patient, look at their disease and valve, and then we look at all the treatment options available, and say, where does this valve fit in this treatment? We respect each other’s opinions. I feel that is something that is not emphasized enough in comprehensive mitral programs, which are few in number. Treatment of the mitral valve was a central part of what we started, then we grew into everything else.
Can you share your program’s experience with ECMO?
We are an experienced ECMO center. In unstable cardiac patients, the indication for ECMO is to restore stability. What ECMO means is that the patient is not stable. They are not going to stay alive; their heart, as things stand, is not capable of supplying the body with the blood it needs, for a number of different reasons, but essentially, it comes down to the heart failing. You have a number of options in that scenario. One is to place a left ventricular assist device. In this case, when we initially got the call about the patient, he was with a very good cardiologist in our community, Dr. Sakina Kamal. She had picked up very early on that this patient was headed the wrong way. The blood pressure was low, the patient was not stable, and there was a much worse situation with the mitral valve itself. We had a conversation on the phone, and very quickly, we emergently transferred the patient via ambulance to Princeton. We knew we would have to go on some kind of left ventricular support or ECMO, for a number of different reasons. He was so unstable at the time. We decided to go on ECMO to steady the ship. In ECMO, you put a large catheter in the vein, pull out blood, and put oxygenated blood back in via another large cannula in the leg artery. The blood is returned at such force that it is able to maintain the blood pressure of the body. It allowed us to make sensible decisions regarding the mitral valve.
Why ECMO in this case versus a left ventricular support device?
Two reasons. It needed to be done very fast and it needed to be comprehensive. The patient was not oxygenating well. His lungs were damaged by the heart failure caused by the valve and ECMO allowed us to oxygenate, as well as keep the blood pressure correct. He was in profound shock. We knew that the valve was the problem and once we fixed the valve, it would get better. This patient had just had a large heart attack as well. There was a large concern that the valve itself had ruptured. The muscle that holds the valve in place had basically come off. We knew this was going to be a complex MitraClip procedure. ECMO leaves us alone inside the heart while keeping the situation stable. Other devices that maintain pressure would need to be put inside the heart and knowing we had a complex intervention ahead, I did not think that would be a smart decision. We have a team that trained in placing ECMO very quickly and they can either do it at the bedside or in the cath lab. The difficulties from a procedural standpoint were in working around the ECMO cannula in the vein. There is a large cannula already in the vein and you are putting a large MitraClip sheath in there. We have done a number of cases in a similar fashion, and typically it is just a matter of being careful and respecting the large sheath that is in there already.
Can you tell us more about placing the MitraClip?
The most challenging part of the procedure was the torn muscle that holds the valve together, because of the heart attack. The ECMO was challenging, but that was challenging too. We were happy that this was not our first clip. At the time of this case, we were already an experienced MitraClip site, having done over 250 cases already. There was no anxiety about getting the clip into place. It is nice having a team that works like clockwork. Because the muscle, with that whole valve in place, tore, it was flying around the heart and we had to catch the leaflet while being very careful for this muscle not to get in the way. Our imaging and anesthesia teams were wonderful. The images provided made everything clear, so that once we had everything stable, the procedure itself went relatively smoothly. We were able to grab the leaflet and stay out of the way of the torn muscle. Almost immediately, when we had the MitraClip on and released it, the patient’s blood pressure returned to normal. We were able to wean him off ECMO the next day.
How is the patient doing now?
It is so wonderful to see him follow-up in clinic. He is walking around like nothing happened. He is the quintessential poster child for someone who was on the brink of dying and is now doing well.
Do you have any comment on the recently reported MitraClip clinical trial data?
The results from the COAPT trial are mind-blowing. That is the only word I can use. It is one of the most spectacular trials we have ever seen in cardiology. It proves that MitraClip has a very large role in helping hundreds of thousands, if not more, very sick people whose lives are going to be saved. It is not often that you can say that about a device. We are going to make them feel better, keep them out of the hospital, and amazingly, save their lives by doing this procedure. It is important to know how to interpret the trial findings, meaning that these patients need to be very closely medically managed, the procedure needs to be done by an experienced team, and patients need to be very closely followed afterwards. What we do not want is everyone suddenly trying to treat every functional mitral regurgitation patient. We must be judicious in patient selection, use a team approach, and have procedural efficiency. Optimal management of heart failure is the cornerstone prior to consideration of any intervention. If we can have those three things, we stand to help a large number of people. Remember that the MITRA-FR trial does not compare to the COAPT trial. Although MITRA-FR was an excellent trial that has provided important information, the COAPT trial is hard to beat when it comes to trial design, follow-up, and comprehensive assessment of outcomes. Patients in the MITRA-FR trial were felt to be, in general, further along the disease process. Yet MITRA-FR is a useful trial in that it tells us the patients who probably won’t benefit. These are the patients who have gone too far along in the course of their disease and essentially, we have missed the boat. We have to catch patients at the right time and not treat the wrong patients, as in those with too-big hearts or those where the leaflet is not actually causing the problem.