Talking Tall Rounds: 2024 AATS Highlights

Podcast Transcript

Announcer:

Welcome to the Talking Tall Rounds series, brought to you by the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic.

Eric Roselli, MD:

Good morning everyone, and welcome to another Tall Rounds session. This year, 2024, the premier academic meeting in the United States, the American Association of Thoracic Surgery (AATS) was a really special event for a lot of reasons. In my count, there are at least 63 different times we had a Cleveland Clinic personnel who was on the podium either moderating our session or presenting a talk. So yes, we dominate cardiothoracic surgery in a lot of different ways, but we definitely did at the AATS meeting this year. We had speakers from our medical student researchers, to the very top of our leadership with Beri Ridgeway and Tom Mihaljevic, and of course, the president of this great event was Dr. Lars Svensson, our esteemed leader.

And so we thought it was only appropriate to do as we've done the last couple of years and have a Tall Round session where we present just a few of the highlights. Clearly, we're not going to give you 63 different presentations this morning, but various highlights from some of the different sections that were presented at the ATS meeting, I hope you enjoy this.

We're going to lead off with Michael Tong, who's going to talk about heart failure, LVAD and transplant, and MCS, and he literally still wearing his surgical cap, came straight from a transplant and the heart's working, and now Mike is going to work in another of his capacities. Thanks, Mike.

Michael Zhen-Yu Tong, MD:

Yes, this was truly a special AATS for us for all the reasons that Eric mentioned, and in the heart failure section we're very well represented. The theme of the meeting when it came to heart failure was really the innovation that has taken place in the field over the last five years, and it feels like the first time in a long time we've really had significant progress in technology. Particularly with the DCD hearts, which is donation after cardiac death, this has really revolutionized heart transplant, has increased the number of donors that are available to us by about 25%. And early on with the DCD experience, it was only the direct procurement that was the only way possible, and this is essentially taking the heart out, putting the heart on a machine called the OCS and perfusing the heart with the OCS machine.

But now over the last few years, NRP, which is essentially resuscitating the heart in the donor itself with ECMO before using the heart, that technology has really came to fruition. And now the market share between these two technology and DCDs are equivalent with identical outcomes and identical usage. The acute rejection, however, was slightly higher when DCD was used in LVAD patients. However, the survival was still similar. There's still a lot to learn with the DCDs, but it's truly an exciting time and particularly for our patients because their wait times have come down significantly.

Also, Billy Cohn presented the experience that he had in animal studies with a new artificial heart, which is called the BiVACOR Heart, this is a very unique system that is unlike any other device out there. And when he presented, they were getting ready for the first human trials, which was just done two weeks ago, the donor received the BiVACOR, did extremely well, survived for seven days, received the heart transplant after that, and continues to do very, very well.

The third innovation is Xenotransplantation, as we have seen and heard about. You may not know, but now we've had two recipients of a Xenotransplantation. The first recipient lived to 60 days, second lived to 40 days, and in both cases add up to about 30 days. The heart from the pig looked absolutely perfect, and you would not even know if you looked at the echo that this was a pig heart. However, beyond 30 days, both patients succumbed to rejection. The heart became extremely swollen. There was extensive amount of lysis and the rejection of these Xeno Hearts, and it's still something that we still have a lot to learn. But nevertheless, this is something that is much shorter in the horizon than it used to be.

Cleveland Clinic was very well represented. We had two invited talks, we have four original manuscripts and four other invited discussants and panelists. I'm just going to highlight three studies. So Aaron Weiss presented our entire series of HeartMate 3. We have the largest experience anywhere in the world with the HeartMate 3 device, and the results are excellent. So we've been participating in the early usage of the device in the early trials, and now we are the largest implant center anywhere in the world. We've implanted 431 consecutive patients, and most of these patients since the new allocation change to 2018 have been destination therapy patients so a sicker cohort of patients.

But despite that, our survival to discharge is still 94%, and our one-year survival is 88%, and our five-year survival is 58%. And let's just not forget how sick these patients are. If we go back 20 years and think about the REMATCH trial, the one-year survival in this group of patients was less than 25%, and the two-year survival was only 8%. Now we have five-year survival that has increased now to about 60%, which is not that different than transplantation on a much sicker cohort. So this technology has been absolutely groundbreaking for this group of patients.

The next study I want to highlight was a paper presented by one of our medical students, Jean-Luc Maigrot, he presented our entire series of surgical implanted Impella 5.5 devices. Again, we are the largest implanting center in the world. Over the past few years, we've implanted over 220 of these devices. Half of them are in ischemic, half of them are non-ischemic centers. And what he wanted to look at was what are some of the predictors of when these patients did poorly? The complication rates for these patients and the mortality are still high, about 17% to 20% in both cohorts. However, this is an extremely, extremely sick group of patients. In patients with cardiogenic shock following acute MI, for example, these patients typically had a mortality about 50% and with this device, the mortality has come down significantly.

We've found different variables that predicted the poor outcomes, but ultimately it really came down to four main predictive categories. Number one, how much cellular injury is there? How much myocardial death is there? Number two, what are the other end organs that are affected? And number three, how is the RV doing? And number four, whether or not this is a small LV or a large LV. Patients with small LVs did worse.

And finally, the third study I want to highlight was one done by our research student, David Moros. He looked at our series of patients who had Impella in the setting of ventricular septal rupture. This is a deadly, deadly condition when you have a ventricular septal rupture, which is essentially a death sentence. And if you look on the right, this is what the myocardial tissue looks like. It's like hamburger meat. There's really no tissue to sew to. And if we can delay taking these patients to the operating room and let that tissue remodel, we have much better tissue quality and often we can approach it from a right atrium as opposed to a ventriculotomy. So to bridge these patients to a more chronic state, we have been using Impella to stabilize these patients.

This is all patients since COVID, essentially since 2020 started, we've seen an increase of ventricular septal ruptures during this era, and we've had 10 patients and seven of those patients we did use an Impella. And when we looked at what happened to all these patients who received an Impella, who then went on to get surgery, all of them survived, which is absolutely incredible feats. So these are some of the highlights of some of the studies that we presented. Again, it was an honor to participate in it and thank you for this attention.

Eric Roselli, MD:

The AATS is the American Association for Thoracic Surgery, and in America, unlike some other countries, we are the same thoracic and cardiovascular surgery. So we're going to shift gears from the heart over to the other space in the chest, and we're going to ask Siva Raja to speak to us about some of the really kind of world-leading work that he's done and our team has done looking at long-term outcomes in patients with esophageal achalasia, Siva?

Siva Raja, MD, PhD:

Thank you for the opportunity to present some of our work that we presented at the AATS. You know, it was a great meeting as everyone's pointed out so far. The Cleveland Clinic was very well represented with three abstracts, with podium presentations and several invited talks. Today we're going to focus on one of the talks that was given by John Barron, one of our research residents at the AATS. We're going to be talking about Heller myotomy for esophageal achalasia. It's a relatively rare disease, and as with many things at the Cleveland Clinic, we are able to move the needle on rare things and make them less rare so we can actually study them, and identify the optimum way to treat these disease processes.

Briefly, achalasia is a rare disease. It happens in one in a hundred thousand people. So it's not as rare as winning the lottery, but it's rarer than getting coronary disease or Mitral valve disease, but it's quite rare. The absence of esophageal peristalsis where there's no motor function to the esophagus, in addition to the combination of their lower esophageal sphincter not relaxing, results in significant swallowing problems. Food gets stuck, food comes back up, they get chest pain because it's not going through, and obviously weight loss associated with it.

For about 111 years now, the classic treatment for this procedure has been a Heller myotomy. Now, as with every procedure in modern medicine, the way in which we do these procedures has evolved over a century, and so has the Heller myotomy. It went from a thoracotomy, to a laparotomy, to laparoscopy, to robotic surgery and even in the endoscopic field. So the treatment involves dividing the lower esophageal sphincter muscle, so it no longer provides an obstruction and it facilitates passage of food. And even though this has been around for over a hundred years, we still don't know as much about it as we think.

We're going to talk about an average patient that we would see with this, and then we are going to talk about what we've learned from our experience the last 20, 25 years, and figure out how we can help that patient. So it's a forty-year-old female who presents with dysphasia, regurgitation, and no prior treatment, and they've been identified as having achalasia. And we've then talked to the patient about having the appropriate treatment for which would be a Heller myotomy. And when they ask you, "Well, doc, how are we going to do with this? Am I going to be okay?" And so far, all we can say is that, "In the short term, you're going to be great." And then the next question is, "What happens later?" "Well, we don't really know." Only in the sense that because it's rare, it's not often studied to the same extent.

The rationale for the study was to identify the Heller myotomy as “is it really the gold standard”? And fill in the gap where there's a paucity of long-term data and because of that, there's no consensus in how to follow these patients. It's not cancer. It's a benign disease, so patients live a long time and as a result, it's not necessarily about saving their lives, it's about making their quality of life in their lifetime good. And of course, long-term outcomes are needed to inform us on how to manage these people in the short term, medium term, and long-term.

So the objectives of this study were to look at re-intervention. So if you're going to make an intervention, then it's important to know how often are you going to have to redo it. Symptom palliation, if the main reason they came to see you is they couldn't swallow is how often are they better? And esophageal emptying and to make sure that if the mechanism of dysfunction is inadequate esophageal emptying, are we making it better?

So in a 25 year period, we looked at over a thousand patients and basically the majority of these patients were performed in this time period in a minimally invasive fashion. Laparoscopically first, and in the last five or six years, almost exclusively robotically. A fundoplication was included in these. A fundoplication is a sort of man-made sphincter valve. Once you open the lower esophageal sphincter, it's open all the time. As you can imagine, if food can go down well, it can come back well as well, so reflux is an issue. To mitigate the consequences of the operation a partial fundoplication is performed in the vast majority of patients. So re-intervention is looked at any type of re-intervention, are they using balloon dilation? Are we going to repeat this operation? Are we going to repeat this operation endoscopically? Or use the WMD option of thoracic surgery, which is esophagectomy where you take the whole thing out and start from scratch?

We did follow our patients annually for the first three years at least, and then every two to three years thereafter. We use symptom scores to identify how well they're doing as well as objective measures and barium swallow similar to the one I showed you earlier. And in a cohort of 1,010 patients, 134 patients required about 187 re-interventions. So the majority of patients actually did quite well. And we can see here that the number of patients requiring esophagectomy is quite low.

So as Dr. Blackstone will tell you that numbers have to be put in context with time and time-dependent factors. And so over a fifteen-year period, about 81% of patients were free from re-intervention. And it turns out that when you re-intervene on somebody who need a re-intervention, a good number of patients could be rescued for a fair bit of time. But the most important thing is that you get to keep your esophagus functioning so that you could avoid an esophagectomy. In a course of 15 years, about 98% of patients were able to preserve their esophagus from this disease process.

Now, now that we know that you don't have to redo it, how well does it work? Well, as we mentioned earlier, there are several categories we use to measure symptoms and therefore symptom severity, and then subsequently symptom relief. Dysphasia or food getting stuck, chest pain is self-explanatory, regurgitation as you eat and food comes up right away (not to be confused with acid reflux) and weight loss. And traditionally, an Eckardt score of zero, meaning that you have no symptoms is something that we see quite often after surgery and as you can see in this plot, that over time there's deterioration of patients who have no symptoms.

So if you operate on somebody and tell them to call you when they're not feeling very well and you tell them that they're not going to have any symptoms, I think you'll be reasonably accurate right after surgery but as time goes on, that deteriorates. But historically, we accept that a score of three or less is considered to be successful and if you use that category, about 73% and 10% have very minimal symptoms. And you can tell the patients who had no re-interventions a slightly higher percentage of patients have fewer symptoms as expected. And of course, you can predict the patients who required a future re-intervention just based on their symptoms.

Now, good news is that after you re-intervene on somebody, you can return them back almost to where they were before. And the last component is looking at esophageal emptying, and the way we look at this is looking at a barium swallow, but it's done in a different way. All patients with achalasia, their esophagus is quite abnormal so doing a standard one is always going to be abnormal. This was devised at the Cleveland Clinic about 30 years ago. It's called a timed barium, this is specifically look at patients with achalasia. Where we basically have them drink a certain amount of contrast and have the X-rays done at one minute and five minutes and to see how quickly it empties.

So for a patient with achalasia, it may take five minutes to empty and they may feel fantastic, but for you or I, if you didn't have achalasia the esophageal emptying should be about 30 seconds. And so looking at complete emptying, it tends to be a quite high frequency right after surgery with some deterioration over time. As we noted, it's not necessary to have complete emptying to have excellent symptom relief. And obviously patients without needing a re-intervention their esophagus emptied better, so if it empties better, you have less symptoms. That is what we are showing as well as it would be expected. What we noticed was that patients with re-intervention, their esophagus did not empty very well at all and after re-intervention, as we noted earlier, they all felt pretty good after your re-intervention. But if you look at them objectively, they don't dramatically improve so there is that discordance between patients, how they feel and how their esophagus actually does.

So in conclusion, going back to that patient that we saw in clinic earlier, the 40-year-old patient, while we can tell them that at 15 years there's an 80% chance they're not going to need anything done, and if they are going to need something done, the vast majority of times it's an endoscopic intervention. The need for esophagectomy is quite rare and Heller myotomy provides durable long-term palliation for esophageal drainage.

In the advent of newer technologies that are developing in endoscopic space to treat this, this is the bar that that has to live up to. So before you can dethrone the king, you need to have the appropriate data to back you up. So what we do based on this data is that the annual follow-up for three years, because the majority of failures happen in the first few years, they're done with both symptoms and with objective measurements. And then once you know they're doing okay, we know that the risk of failure is not zero, but quite low you can follow them every two to three years. We do use endoscopic evaluation every five years for surveillance, the assumption is that with this mod there is a higher risk of esophageal cancer, it is likely to manifest itself 10 to 15 years after intervention. So at the moment, we are recommending endoscopic follow-ups every five years lifelong. Thank you.

Announcer:

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