Hi, everyone. I want to welcome you to San Diego and the first day of HRS 2025. I'm Nashwa Abdul-Salam. And I'm Brittany Hurd. We are excited to guide you through this session on updates on hybrid ablation and management of atrial fibrillation. Just a few housekeeping things. We will have four speakers today. If you've not already done so, go ahead and download the HRS 2025 mobile app from your preferred app store. That's how you'll be able to participate in live Q&A during sessions. Please scan the QR code that's shown right there to assess this question's Q&A. When using a mobile app, you'll just use your own login, your HRS credentials for logging in. At the end, we'll save our questions and answers for that portion. And there's a microphone if you'd like to ask questions in person, or we'll be looking at the questions online. So our first speaker is Dr. Adol Carpio. And he's going to give us a talk about the role of hybrid ablation for persistent and long-standing persistent atrial fibrillation. Good afternoon. Thank you very much for the opportunity to present today. I have been assigned to talk about discussing the role of hybrid ablation for persistent and long-standing persistent atrial fibrillation. So really I have three main objectives for this talk. The first is to understand the rationale behind hybrid ablations for AFib. We'll describe briefly what are the strategies about hybrid ablation for AFib, and we'll review the most relevant data that we currently have and why we should recommend this therapy in certain patients with persistent atrial fibrillation. Well let's start from the beginning. Currently in clinical practice now, more advanced forms of atrial fibrillation, persistent and long-standing persistent, are really the most frequent forms of clinical presentation in an EP practice. And patients with persistent atrial fibrillation and long-standing persistent atrial fibrillation really are a challenge for management. They have multiple comorbidities, the arrhythmogenic substrate is very complex, and really we have not been doing that great with our endocardial ablation tools, and it's been known for years and years. And really, you know, the mechanism and how much we understand about it, it's that as atrial fibrillation starts as paroxysmal form, it's mostly a trigger-based arrhythmia. But as time goes and the arrhythmia changes, the substrate is more complex, there is significant remodeling in terms of functional, morphological, lithoracial enlargement, as well as myocardial fibrosis in the atria that make our tools and our technology to target triggers not as successful. Besides that, the third pillar of pathophysiology of atrial fibrillation is the modulators, and we're not doing much about, for example, the autonomic nervous system or ablation of the ganglionated plexi that can perhaps have some other benefits. And the clinical data is very clear. This is data from the STAR-AF study that was already 10 years old, and really things have not changed that much. And this study showed that pulmonary vein isolation is just not enough for offering significant results for this patient population. And if we add some substrate-based frequency ablation or you add lines to this PVI, really the outcomes are not different. And this is even after having a repeat ablation procedure. The posterior wall is a very interesting structure, but even that, the CAPLA trial that was published a couple of years ago, showed that if you do PVI alone or you do PVI plus posterior wall isolation, the results are exactly the same. And this is a recent publication of a three-year follow-up of the CAPLA study that was just published in European Heart Journal, showing that after three years, the results are not different. Importantly, after three years, there was 30% of redo procedures, and at least 75% of those patients who had a posterior wall isolation, they have reconnection. Well, the era of PFA, it's here. I mean, it's a lot of excitement. We have a big session next door. Everybody's excited about a PFA, but probably that's the answer. Well, so far, we don't have any evidence that PFA will change things significantly. This is data from a large multi-center registry showing that if you add posterior wall isolation to PVI using PFA, the results are exactly the same. And again, there is no significant data in terms of randomized trials or even comparison with radiofrequency ablation. As I mentioned, the posterior wall is a very interesting structure and probably has significant pathophysiologic role in persistent atrial fibrillation. This is an interesting study looking at the atrial myofiber architecture from endo to epicardium, looking at the complexity of the rearrangement of the myocardial fibers and why that substrate is very complex. And we know, for example, that there is this endo-epicardial dissociation that we see. And maybe, you know, again, this posterior wall should be a good target. But again, we are not doing that great with catheter ablation so far. Back in 1987, the Cox MACE Procedure was described. A few years later, the Cox MACE 3 Procedure has become the gold standard for cardiovascular surgeons. And really, this lesion set was designed to break or to block multiple microreagent circuits that can be culprits, you know, for persistent atrial fibrillation. So this Cox MACE Procedure, I mean, and you can question the data, the follow-up, the type of endpoints, but really has become the gold standard. And the main thing about this is that by cutting and sewing, the surgeon can do transmural and durable lesions. And that's really at the bottom line. Over time, that Cox MACE Procedure has evolved. In the 21st century, there has been multiple iterations for this technique until it has been less invasive because the cut-sew procedure requires cardiopulmonary bypass. It's not exempt of significant complications. Even cardiovascular surgeons cannot adopt that technique, you know, universally. But over time, we have less invasive things trying to simulate, again, the Cox MACE 3 Procedure. Fifteen years ago or so, the hybrid ablation was described, but it's only four years ago that we have the first randomized clinical trial of the hybrid procedure for persistent atrial fibrillation. The surgical MACE, again, without the cut and sew, this thoracoscopic approach actually can target multiple things. Can isolate the posterior wall using these rate of frequency or cryoablation clamps, can perform linear ablation of the posterior wall, can exclude the left atrial appendage, can even target the ganglionated plexi, providing a more comprehensive lesion set for this more complex patient population. So what is hybrid ablation? It's really, you know, a synergy of work between the cardiovascular surgeon who takes care of the picardial work. It has a direct visualization of the anatomy. It can dissect the picardial fat, so it can apply more durable lesions, can avoid injury to the phrenic nerves, and of course can also exclude or isolate the left atrial appendage as well as transect the ligament of Marshall or ablate the ganglionated plexi. The electrophysiologist is in charge of the endocardial work, and it can perform a high density mapping, so it can find incomplete picardial ablations and can complete those gaps and testing with comprehensive heart endpoints. In addition to that, it can also target different triggers for persistent atrial fibrillation. So currently there are three main techniques for the hybrid ablation. This is the bilateral thoracoscopic approach using these rate of frequency bipolar and biparietal clamps that unblock and isolate the posterior wall and the pulmonary veins. It can be a unilateral thoracoscopic approach using, again, rate of frequency clamps that can isolate the veins, and using a picardial pen can do ablation of the posterior wall. And the conversion procedure, that is a different technique, and you will have a different talk about that technique. What is the data? Really, two randomized clinical trials. The first is the CISAF trial that randomized patients with persistent atrial fibrillation to a hybrid ablation. It consisted of a picardial, PBI, and left atrial posterior wall isolation, exclusion of the left atrial appendage. And in a second stage, three to six months later, there was a touch up lesions by the electrophysiologist. The second group, catheter ablation using PBI and optional substrate modification, and even included a repeat ablation procedure also within three to six months. The endpoint, freedom from AFib, AT, or atrial flutter lasting more than 30 seconds at 12 months. And the outcomes were clear. Catheter ablation did significantly better overall, 72 against 40%. And in both, persistent and long-standing persistent, the outcomes were clear. The complication rates were non-significant different. So the conclusion was that hybrid ablation is more effective than catheter ablation for persistent AFib with similar complication rates. The second study is the HARDCAP-AF trial. This study was published just a couple of years ago. And interesting, it's really a small group of patients. The hybrid group was 19 patients, again, PBI plus posterior wall and left atrial appendage exclusion. And in a single stage, so actually almost simultaneous endocardial validation and touch up of the ablation plus CTI line. And a second group of catheter ablation of 22 patients that had PBI plus posterior wall. And a repeat ablation was also permitted in that group. The endpoint was a slightly different endpoint. This one was freedom from AFib lasting more than five minutes at 12 months. The outcomes, and even in that small group of patients, look at the results and were clearly beneficial for the hybrid ablation, 89 against 41% of antiarrhythmic drugs. And with antiarrhythmic drugs was 95%, again, 41%. Each group had one complication that was not significantly different. And again, hybrid ablation was more effective than catheter ablation for persistent AFib with similar complication rates. This is what you see in the second stage of the procedure. You see that the posterior wall is isolated. And then sometimes you can complete another ablation gaps in the posterior wall or the pulmonary veins. And then additional ablations like, for example, in this case, a mitral isthmus. So what are the considerations for hybrid ablation? So there are certainly some advantages to that. First, I mean, it can offer a comprehensive lesion set. It's being shown, at least in limited data, that it improves outcomes for persistent and long-standing persistent AFib. It can target non-PV triggers, including isolation or exclusion of the left atrial appendage. The challenges, first of all, the evidence is, again, mostly from single-centered studies, only two randomized clinical trials. There is some complexity about coordination of the procedure between the surgeon and the electrophysiologist. And there is still some unknowns. For example, what the workflow should be, what should be the timing of the second stage, should be simultaneous. If it's a second stage, should it be weeks, months later of the surgical procedure? And of course, this is not available to all patients. There is some limited access. And there is a higher upfront cost. So in summary, hybrid ablation, again, we still have no good understanding about the pathophysiology of persistent atrial fibrillation. Whatever we're doing with the endocardial ablation, again, our recurrences are still high. Hybrid ablation can offer a more comprehensive approach. There is, again, a synergy of the surgeon and the electrophysiologist in order to perform transmural durable lesions and targeting of non-PV triggers, including the left atrial appendage exclusion. And the evidence of hybrid ablation is growing, but still it's limited to only a couple of randomized clinical trials. Thank you very much. Thank you. Next, we'll have Dr. Gorey of Coral Health West discussing convergent versus convergent plus ablation. Okay. Good afternoon, everybody. Thank you very much for allowing me to discuss the hybrid ablation for AFib, the convergent procedure, which is a little different than the procedure we just heard about, but still considered a hybrid ablation. It's versus the Convergent Plus. I have no relevant disclosures. So as everyone in this room knows, AFib is a progressive disease. It starts out with normal hearts, with paroxysms of it, and then it progresses. And if it's not properly treated, the disease tends to progress. And unfortunately, you know, the vast majority of patients that we see over time here, you see 30% are estimated to be paroxysmal, and the other 70% are more advanced disease. And that's unfortunate for us because we have a really good option for when it's early, and options for when it's later disease are a little more limited. Oops, what did I do here? Sorry about that. I must have clicked the wrong button. The good news is it restarted my time clock. Okay. Here we go. So is PVI alone enough? Well, as literature has clearly demonstrated, it works very well for paroxysmal AFib. It's the gold standard, and in multiple studies, the data is very robust. However, as we heard in the previous presentation, for persistent AFib, it's totally another story. Multiple studies have shown that the success rates are less than 60% with PVI alone, and as was also demonstrated in the last presentation, the STAR-AF2 trial showed that there's really no benefit to doing more when you're doing it endocardially. So endocardial ablation is equally bad as PVI additional substrate modification when it's just being done with a catheter-based endocardial procedure. There is a recent meta-analysis that was just published in the Heart Rhythm Journal this year that showed there might be an advantage of doing more AFib ablation besides the pulmonary vein. However, once again, in randomized controlled trials in Kuhlen-Kaplow, the posterior wall, this did not bear out to be any better than PVI alone. So the question, why does endocardial catheter ablation fail in this population of persistent atrial fibrillation patients? Well, it's because the disease has progressed. It's not just triggers from the pulmonary vein, but it's the appendage, the ligamental marshal, the posterior wall, other sites. And with endocardial catheter-based ablation, transmurality can be limited. There's an endocardial dissociation that has been demonstrated, talked about in the prior presentation as well, that might be the reason that we don't do well with endocardial-based catheter ablations alone. Clearly, there's a need for expanded ablation beyond pulmonary vein in advanced atrial fibrillation. So, come to the hybrid epicardial-endocardial convergent procedure. So in this procedure, it is done, once again, with a surgical team and an electrophysiology team. For the first time, when we started doing this, we got the surgeons and the electrophysiologists to play in the sandbox together, a place we're not comfortable, but we've become friends, and we actually meet on a regular basis in a heart team meeting to discuss these complex cases and what to do. But stage one of this procedure involves the surgeons doing subxiphoid access and ablating the posterior wall. And once again, this is just the initial convergent study, not the convergent plus, which we'll get to. And then that procedure terminates, and then later on, the electrophysiologist comes back, touches up the pulmonary veins, the posterior wall, using either radiofrequency, cryo, or PFA. So, the advantages of the hybrid convergent approach are twofold. One, it's a much more reliable, homogenous set of posterior wall lesions. When you do a posterior wall isolation endocardially with catheter base, all it takes, if you're doing a box-type lesion, one little gap, and it's like you didn't do anything at all. Where there's redundant lesions being applied epicardially, as well as when the patient comes back for a repeat mapping, endocardial lesions can be done as well. And additionally, it reduces the risk of collateral tissue damage. Obviously, the biggest concern that you have as an electrophysiologist is hurting a patient and damaging the esophagus, causing an atrioesophageal fistula, is one of the most feared complications, which is probably why we were very timid to ablate more aggressively along the posterior wall when we were trying to do this all endocardially. So, patient selection. Obviously, for earlier stages of AFib, there's really no need to send a patient for this two-staged procedure. But in this set of patients here, where there's more advanced AFib, the substrate has changed in large left atrium, scarring in the posterior wall, prior failed ablations, other comorbidities, obesity, heart failure, patients that you know a standard ablation will not be successful, these are the patients that are best utilized for this technique. So, what is the data for this? There was an IDE study, the CONVERGE study, that was published a few years back that looked at randomizing patients between a hybrid convergent ablation, as I just described, versus an endocardial catheter ablation, which included pulmonary veins, a roof line, and a CTI line. And here you can see from the data, these curves diverge right after the blanking period, where the convergent ablation procedure had a statistically significant benefit. And there's not many randomized controlled trials out there that show benefit of doing more than a pulmonary vein isolation in these patients. So, this was an exciting study. This was published almost four years ago, I believe, and really kind of proved the reason for what, that this procedure finally had some evidence-based behind it. So, going back to what we've done at Spectrum-Corwell, we used to be Spectrum, the last two years before we became Corwell, but our journey began in 2017. At that point, it was a staged procedure, and a year later, it was still staged, but we staged it just two days apart, not 30 days apart, and we added 3D mapping, that the cardiac surgeon would use a high density mapping catheter to help them guide lesion sets epicardially. And then the next year, we added the left atrial appendage clip to the procedure, and then the year after that, well, actually, it was just in select patients. In 2020, it became routine for almost all patients. It does require a second incision in a VATS-type procedure, so that's why we're only doing it in select patients initially. And then in 2021, we added the ligamental marshal. So, what has this data shown? Last year, we actually published our experience in Heart Rhythm, and what the convergent plus is really the evolution of the convergent procedure. In the CONVERGE study, it did not include any of these elements, so 3D mapping, left atrial appendage clip, and ligament and marshal resection. So, here's our data on this procedure at our institution. You can see freedom from AFib in 170 patients with a mean duration of AFib of almost five years, and almost 60% had had a prior ablation, 87% freedom from AFib at one year, so really good numbers. And it's not just, you know, the endpoint that we use, that we're forced to use here, which obviously is something that gets debated back and forth, is 30 seconds of AFib on a monitor, a failure. If you have a persistent patient that's been in AFib for three years, and they have two minutes of AFib off antirhythmics, that would constitute a failure here, but clinically, it's a huge success. So, even using these very stringent markers of success, our numbers were quite good in this paper, in our experience here at Corwell. So, let's look at each of these components individually. So, 3D mapping. Here, there's a diagram showing, on the right-hand side, you can see what the epicardial map looked like prior to ablation, and in the left-hand is after the surgeon has delivered lesions. In our experience, this actually did prove to be statistically significant for an improvement in AFib burden reduction. So, this is now, once again, part of our standard procedure. The surgeons, we were a little reluctant to give them our tools, but we did, and they seemed to do a pretty good job with it regardless. But I do believe it has benefits, and it's proven in our experience as well. So, the left atrial appendage, probably the biggest adoption to this addition to the convergent procedure. You know, the left atrial appendage clearly is an enemy to the patient with atrial fibrillation, for the main reason being stroke. And clearly, if you can eliminate the patient's stroke risk, that is paramount for every provider taking care of patients with AFib. So, you know, the LAOS 3 study that was published recently really kind of answered this question definitively, quite definitively. So, this was a patient looking at almost, a study looking at almost 5,000 patients undergoing cardiac surgery that randomized to having an appendage removal, either clipping or over-sewing or no occlusion, and all the patients remained on anticoagulation. Here you can see the curves diverge, and so this really conclusively demonstrates that removal or closure of the left atrial appendage reduces stroke in patients with atrial fibrillation undergoing surgery. And as a result, in the most recent guidelines, here it became a class 1A, so highest level of evidence that all patients undergoing cardiac surgery should have their left atrial appendage managed. So, besides reducing the stroke risk, we were interested in does this help with the AFib outcomes? So, here in this diagram you can see what the epicardial map looks like of a left atrial appendage, of a left atrium without the isolation, and here you can see once it's isolated, it's obviously eliminated. So, there's mixed data on whether this helps, and in the studies we have, the AMAZE trial with a Lariat device showed that there really wasn't significant benefit. There is some other randomized controlled trials in the BELIEVE that did show that this helped. So, the jury is still out on this, but if nothing else, removing it for the stroke risk clearly is beneficial. Looking at, this is the group out in New York with Dr. Felix Yang, learning their experience of hybrid convergent with left atrial appendage versus without. Here you can see they did have a statistically significant benefit in AFib reduction in this group. And then I'll just, this was our experience here at Corwell. We did not show a benefit in our experience, but there was a trend. So, once again, removing the stroke risk is paramount. I'm running out of time, so I'm going to go through these next two slides quickly. I'm almost there, I apologize. VANA-Marshall. So, the ligament of Marshall was the last thing we added. Here, the VENUS study showed that alcohol ablation of the VANA-Marshall did lead to clinically beneficial success rates. Once again, not many randomized studies have shown that. So, that became something that we focused on. Here's a picture of the ligament of Marshall. It's a pretty simple add-on procedure for the surgeon. Once they're already doing the left atrial appendage management, this takedown is quite easy. Once again, didn't, in our experience, a trend towards success, but didn't meet statistical significance. And here's the totality of all the published data on the convergent study. And you can see, these numbers are all quite good. So, as I said, in the population endocardially, everything's less than 60%. Here, 60% to 85% have been shown in several different studies. So, in summary, the convergent study, we know that advanced AFib, PVI alone, has limited success. The posterior wall ligament of Marshall and left atrial appendage are clear substrate for sustaining AFib. And in this procedure, they can be relatively easily addressed. 3D mapping has been shown to improve outcomes. Left atrial appendage management, probably one of the biggest benefits of this procedure. It clearly lowers the stroke risk, may lower the AFib burden. There's data that suggests that. And ligament of Marshall, as a clinical electrophysiologist, we see that this structure is really arrhythmogenic. And, you know, I do ligament of Marshall or vein of Marshall ablations all the time on my endocardial cases. And it, you know, clearly in some patients, it's a big trigger for AFib. So, final statement, convergent plus yields long-term outcomes for advanced AFib that's similar to seen in paroxysmal AFib. You know, if you can get 75% to 80% in this population, clearly that is pretty significant. And there's clearly a role for this procedure in patients with AFib. So, thank you very much. Thank you. Our next speaker is Dr. Kessler, and he's going to be presenting a critical appraisal of the role of hybrid ablation in the management of atrial fibrillation. Thank you very much. It's a great pleasure to perhaps give an electrophysiologist's review of the literature around surgery. And I'm very grateful to Freddie and Andre for really covering a lot of the trials that I'm going to present to you, so it'll allow me to move quickly. So, where are we at with the current guidelines for the role of hybrid ablation? Well, essentially, it's a 2B recommendation in patients with symptomatic persistent AF refractory to drugs that the hybrid procedure may be considered or may be reasonable to reduce the risk of recurrent atrial arrhythmia. And that really contrasts markedly with the current recommendations for catheter ablation. So we're really going to explore the background for that. So we've already heard a lot about the limitations of catheter ablation. And I don't take up any argument when it comes to RF-based catheter ablation. Pulmonary vein reconnection remains challenging. We get better results with paroxysmal rather than persistent. And then there's another reduction in success when it comes to longstanding persistent AF. Big left atria are more challenging. We're really not sure what to add on beyond PVI to try and get better outcomes. And as you can see, the current recommendations are a 2B for adding anything beyond PVI in cases of persistent AF. And we've continued over more than 20 years, really, to battle with the durability of radiofrequency ablation. So again, we've heard about the advantages of hybrid ablation. The beauty of marriage between surgery and electrophysiology means that we can prove electrophysiologic endpoints. It's always been a huge limitation of surgery alone. This kind of concept of proving isolation just by attempting to pace and saying there's no capture is far from an acceptable electrophysiologic endpoint for isolation. Transmurality would seem more likely to be successful if you're coming at the myocardium from both sides. And there's certainly literature, as Andre and Freddie have shown, to support improved success in the setting of longstanding persistent AF. The disadvantages are, without argument, that it's more invasive. The procedure takes longer. The hospital stays longer. The patient recovers longer. It's more expensive. And it is associated with more complications. So there's a lot of focus on the posterior wall. And there are a whole bunch of theoretical reasons why it's an attractive target to both surgeons and electrophysiologists. It has a common embryologic origin to the pulmonary veins. It's certainly a recognized source of non-PV triggers. It houses the parasympathetic ganglia. Also a site of proximal rotational activity. It gives us a kind of belt and braces approach to pulmonary vein isolation. And it also debulks the atrium. And if you think about the multiple wavelet hypothesis, we believe that there needs to be sufficient critical atrial mass to sustain atrial fibrillation. It also houses a really important structure called the septopulmonary bundle, which can be a site of wavefront collision in the setting of triggers, which tend to fractionate and sustain atrial fibrillation. We've heard a little bit about SAR-AF2. But there's also DCAF2, which essentially involve randomizing patients to PVI alone versus PVI plus. A mutagenization of regions of delayed enhancement on CMR. And then the trial that I was involved with, we've heard also about the Kapler trial, which showed absolutely no benefit with adding posterior wall isolation. Again, all RF studies. So just to highlight the way we isolate the posterior wall with catheters, we tend to generally take a linear approach, as you can see here. And as has been highlighted, the epicardium is our nemesis. And in our studies, we generally need to ablate inside the box 50% of the time. And with experience, you can get those sorts of acute isolation rates, so around about 86%, 87%. Now, there's also this concept that the posterior wall is a common site of fibrosis. Therefore, if we isolate it, we're going to get better outcomes. And that's a concept that's well-entrenched in EP, and it's also well-entrenched in surgery. But we looked at this in Kapler. And what you'll see on the left-hand side of the screen there is that across a number of studies, if there is fibrosis, the outcomes are worse. Now, what we then did was we looked at all the patients who had posterior wall fibrosis and compared outcomes of PBI alone versus PBI plus posterior wall isolation and saw, again, a theme of our study, no difference. But importantly, what we found was that if there was low voltage on the posterior wall, then almost all the patients had low voltage elsewhere. So that does translate across to the hybrid-convergent approach. If you're just going to add posterior wall isolation, then perhaps you're not going to improve outcome. Well, the ERASE trial actually went ahead and looked at ablating those regions more extensively in the atrium. And they did indeed find, with a large randomized trial, that outcomes were improved if all regions of electrically detected low voltage were addressed with isolation or bidirectional block. So we've already heard quite a bit about the convergent hybrid ablation procedure, a two-to-one randomized trial of the hybrid approach with PBI only, and the proportion with long-standing persistent AF around about 40%. That's also a theme in this surgical literature is they often talk about long-standing persistent AF. But invariably, most of the patients have a continuous AF duration of less than 12 months. And you've already heard about the success, 67% versus 50%, but a significant increase in complications. And this is really where most electrophysiologists are reluctant to send their patients for surgery. As much as this has tried to be minimized, these are serious complications. Certainly, most electrophysiologists wouldn't accept complication rates of 7% to 15%. Pericardial effusions requiring drainage, stroke TIA, excessive bleeding, phrenic nerve injury, and a 0.0525 difference in the hybrid surgical complications compared to catheter. The other major limitation of all these comparative studies is how can you compare two procedures with one procedure? If you get two shots at endocardial isolation of the pulmonary veins and posterior wall, then the vast majority of patients will have durable PBI without being exposed to excessive complications. Recovery and safety. So can we then just skip the endocardial side? Well, this was a study from UCLA where they actually gave us more information about what happens at the endocardial approach. And while we see those tire tracks across the posterior wall, you'd think that the likelihood of durable posterior wall isolation would be high. But in this study, the posterior wall reconnection was nearly 60% after the epicardial-only aspect to the procedure. So it certainly shows the importance of including that endocardial component. Now, we've heard a little bit about non-randomized data. And we also see this a lot in EP. We see non-randomized small studies which show a lot of promise with add-on components. And then when we subject them to large multi-center randomized trials, we're often disappointed. And this is just a nice case in point. This is the CACER-AF trial where this was non-randomized data which showed a substantial improvement with a surgical approach compared to a catheter-based approach, although not seen when patients underwent multiple procedures. But this was a nice study because it gave rise to the randomized CACER-AF trial, which was confined to patients with longstanding persistent AF. Importantly, all the patients had implantable loop recorders, unlike the minimal monitoring that was performed in the other trials. And it was a bit more like-for-like. So it was the CADO mapping system, PVI plus posterior wall plus lateral mitral line versus the surgical approach with AtriCure, which included PVI posterior wall isolation, the left atrial appendage clip, targeting of ganglionic plexi, and also verification by an electrophysiologist in the surgical theater. And there was absolutely no difference between the groups when it came to arrhythmia recurrence. There were significant differences in favor of catheter ablation when it came to health economic analyses, quality of life, and total cost. And again, the theme of an increase in adverse events was seen with surgical ablation at nearly 40% and catheter ablation with 15%. And given those high complication rates, I suspect the definition of a complication was a bit tough. So the intensity of monitoring matters. We see this with pulse field ablation, and we see it again with surgical ablation. What you see here in each of those graphs is the success within continuous monitoring, so 52.6%. And then we see the success if you just do three 24-hour monitors in the same patient cohort, 92%. If you do three seven-day monitors, 80%. And then we can approximate continuous monitoring if we go to three 14-day monitors. So depending on the stringency of monitoring has an enormous impact on the reported outcome. We've heard a little bit about CSAF, so almost a sort of European equivalent to convergent, but with perhaps a more extensive ablation strategy. A few less long-standing persistent. Again, a two-to-one randomization. In this study, exclusion of the left atrial appendage was included. And also, it was at operator discretion whether they added beyond PVI. Again, the degree of monitoring was not particularly intense. I wanted to just highlight that in the catheter-based group, around about a third of patients, there was some attempt at posterior wall block, but it was only achieved in 56%. And in the surgical group, they often went on and attacked the ganglionic plexi, ligament and marshal, and some other lines. So again, we've heard about the results of this, which you can see on the right panel. What I want to highlight, though, is that in the catheter ablation group, only 89% achieved PVI. So I think this speaks a little bit to the operators in that arm of the study. Certainly, we would not see anything less than 100% for pulmonary vein isolation acutely. You can see the success in the hybrid ablation group of posterior wall isolation at the index procedure. 83%, so comparable to what we saw with Kapler. You can see the procedure duration with catheters, 251 minutes. That's nearly three procedures for us nowadays. So I'm not sure about the efficacy of catheter ablation in this study. The last trial, which I'll go through fairly quickly because it's already been covered, was a very small study of only 40 patients, which did show an improvement in procedural success. What was very interesting, though, as a takedown from this study was there was no difference in quality of life, despite a near doubling in freedom from AF if you look at those outcomes. Now part of that may be explained by this binary concept about the 30 second rule. They either have AF or they've had 30 seconds and therefore they're deemed a procedural failure. In Kapler, Rose Crowley, one of our PhD students, looked in detail at this concept of regression. So we've heard a lot already today about progression. Well, if you undergo PVI, about half will not have AF at all. And another third, so we're up to nearly 75%, 80%, will only have paroxysmal AF. And that translates directly to reductions in health care utilization and quality of life. So this whole concept of a binary outcome is becoming increasingly outdated. Now what about the role of surgical ablation in the setting of failed catheter ablation? Well, there really isn't much literature on this. This study was used in the European guidelines to support the role of surgical ablation. But it included a lot of patients with paroxysmal AF. The proportion with failed catheter ablation was 60% to 70%. So there were some real sort of limitations. But nonetheless, it did show an improvement with surgical ablation compared to repeat catheter ablation. And I must say, after two procedures, they're pretty disappointing results for catheters at 37%. Again, this concept of increased complications with surgery. Well, the elephant in the room, which has been somewhat alluded to, is pulse field ablation. It's faster. It looks like it's more durable. We're just at the beginning of our journey with pulse field ablation. This is the lattice tip catheter where patients were brought back, and the durability of linear ablation beyond PVI was apparent in somewhere between 90% and 100% of patients. And again, on the right-hand panel, you'll see the safety of pulse field ablation. Most of the complications relate to vascular access compared to a meta-analysis of hybrid ablation, showing significant complication rates in up to 6.5%, including mortality of 0.2%. We've also seen this retrospective study looking at the role of pulse field ablation on the posterior wall. And again, this non-randomized study doesn't show any advantage with a single procedure outcome to adding posterior wall isolation. But again, this is single procedure, first generation pulse field ablation. And I just wanted to highlight how short the procedure times are becoming and the option of same-day discharge with catheters. So to conclude, where are we at with hybrid ablation? Well, I would argue that we need more evidence. We need one-to-one randomized trials, not two-to-one. We need larger studies. We need to have a look, really, where hybrid may plug in is in the long-standing persistent population. So we need studies in exclusively this population. It has to be apples versus apples. So it's got to be two procedures in both arms. They have to be equivalent. There needs to be continuous monitoring. Nowadays, it has to be pulse field ablation. And we need independent funding for those studies. So I think, undoubtedly, catheter ablation's faster, cheaper, safer. The patients recover more rapidly. But the question is, can hybrid be more effective? And the endpoints need to be AF burden and quality of life, not freedom from AF. Thank you. OK. We'll have Dr. Wymer now from Eberhard Carl's University School of Medicine discussing complications associated with hybrid ablation. Yeah, thank you very much for inviting me to San Diego. And talk about what my previous speaker already mentioned, the complications of hybrid ablation. I would like to take the chance to comment on one or two things of the CCF trial, because I'm gonna focus on this trial a bit, because we conducted and designed this trial. This is why you're gonna see more or less analysis of the CCF complications and also efficacy. The thing is, what I just noticed, and I'm talking as a surgeon, of course, is that I still feel that we have not the right perspective to hybrid. We call it two procedures to one procedure. We kind of like still separate the complications done by the surgeon and the EP, and that's not the idea of hybrid. It's one procedure. Of course, you do it endocardial and apicardial. But this is one approach to the patient, and the same EP that did those long procedures with questionable results in Cs, for instance, did the endocardial part of my patients as well. So you cannot say, okay, the endocardial catheter part, success rates were too low, I can achieve more, but don't apply the same thing. Then he lowered, more or less, the hybrid success rates as well. So we target the substrate of the posterior wall. Is it important or not the posterior wall? I know there is conflicting data, but I think one main thing is that we were limited endocardially by the trans morality that we can apply. And we can overcome that with tools that we have available as surgeons. That has nothing to do with EP or surgeon. It's just a more powerful tool that we can apply there. And I think this is part of the success if you ablate apicardially and endocardially at the same time. And what we did actually focus on were, of course, longstanding persistent patients in this trial or patients with persistent AFib and an enlarged left atrium. And this is the most challenging patients. We are not talking about paroxysmal patients. I think there no heart team in the world would start to target them. So those patients were actually included in those trials, and paroxysmal was explicitly excluded. So we already focus on those challenging patients where we have limited success with even repeated catheter ablation. In CCF, a repeat catheter ablation was allowed within the first six months. A third got a repeated catheter ablation, and the others didn't. Now, this is something you can question in this trial. Why didn't all of the failures get it? But this is, again, something that also the patient decides at the very end. Does he wanna get another procedure? We did not make that mandatory, of course, at the very end. So if you look at the data, you already saw the success rates of our primary end point at 12 months. There was a significant difference, but that difference was really durable. Over three years, meanwhile, we just published that at the era congress a couple of months ago, and also after three years, you still see a significant difference. The gap was even bigger than at the primary effectiveness end point. And of course, as more advanced AFib gets, as more beneficial this AP endocardial approach gets. So in those patients that got long-standing persistent AFib, by the way, the AFib duration in this trial, the mean AFib duration was three point something years. So that was not like other trials where you, I mean, you can shuffle around a little bit with the definition of persistent, long-standing persistent. But per definition in this trial, the same, by the way, true for hard cap, was a very challenging to treat patient subgroup, let's put it this way. So the CCAF efficacy data was more or less really confirmed by the hard cap trial, which had a pretty similar design and protocol to the trial, but was also confirmed with the converge trial. Because the numbers were pretty much the same, no matter what kind of platform you use. This AP endocardial ablation with targeting of the posterior wall had the same effect in all of those three randomized controlled trials. To give you a little bit of an impression, because of course, and no one will argue with that, apicardial ablation is much more invasive than a catheter ablation. But still, it can be done very straightforward with a relatively low complication rate. And at the very end, you see here how the clamps encircle the pulmonary veins and isolate already a part of the posterior wall. You can, in the same procedure, target the LAA. This is another advantage of hybrid, that you have a very easy access to deal with a left atrial appendage, no matter if you target it as a substrate or if you really target it as a stroke prevention. You do the same thing from the other side, and with those two clamp circles, you isolate the posterior wall. For the convergent procedure, you already saw that lesion set in the previous talks, but this you can consider even less invasive. The other one, you need three ports on the left and on the right side. Here you have one incision uses a cyphoidal approach to target the posterior wall with your device. So you don't have to go through the plural space. It's less invasive, patients recover a lot faster. Even with a bilateral thoracoscopic approach that you saw earlier, patient usually leaves the hospital after two or three days. Why do we keep them that long? It's not necessarily because they don't recover very well, but because we like to treat relapses of our recurrences in the hospital and not by the primary care physician. So now talking about the complications that occurred in C's, we had numerically higher complication rates in the hybrid arm. And I'm on purpose now, because I said it earlier, don't say, but we also did two procedures, so it's clear that you have higher complication rates. No, the complication rates was higher, it did not reach significance in this trial. If you really wanna go down this way of separating endocardial from apicardial, the complication rate of the apicardial part was 4.9. So about two-thirds occurred during the index procedure, which was the apicardial part, and one-third of the complication occurred during the endocardial part. Now, is this a complication rate? Also, if you look at the catheter arm in 5.8, you will say, no, this is not a realistic complication rate. That I see in my clinical practice as an electrophysiologist. I agree with you, but in a randomized controlled trials, your complications, your personal complication rates will be higher than what you see in your institution. We all know that because it's a lot better monitored. And then it's just becoming bad luck at the very end, that you have in the catheter arm a mitral valve injury. You will say, probably, I never had that, or I rarely see that. It occurred in this trial, that's bad luck. But I cannot say, here it's bad luck, and in the hybrid arm, it was good luck, that we had so low complication rates. Were the complication rates disabling? That's also an important thing. I mean, we're talking about maybe bleeding. Most or a lot of those complications were really kind of like associated with entering the pleural space, pneumonia, and one pneumothorax, but we had, you don't see a cluster of complications where you can say you have a high risk of bleeding or whatever. Those were all one patients out of 102, 110, so it's really hard to say complication rate of bleeding is increased by this procedure. If you look and compare those data to data from high volume centers, we here put the data of three high volume hybrid centers in Europe together. You had a similar complication rate that was, because it was not a randomized control trials, but partly the same operators as in the CCAF trial, we had a complication rate of 2.5 for the hybrid arm. So you can say, you always can pull a trial where you have the same exorbitant complication rates as a CCAF trial that you just saw. That was, of course, a killer. I really have to say this. If you see those numbers, that's absolutely not acceptable. But if you look at those three randomized control trials, the complication rates were not different of the two arms. And now talking about, we had it in the previous talk, cost effectiveness and complications. Reintervention after an approach or after treatment strategy, is that a complication? It certainly affects cost effectiveness. If you again look at the CCAF trial, we had, first of all, 70.6% crossing over to an apicardial procedure afterwards. And then we had a lot more cardioversions, hospitalizations of the patients. We had a lot more repeat ablations in the later course. That always involves quality of life of those patients. And it also will increase costs. So what is the end point in cost effectiveness? You cannot look at the primary procedure in those patients. So looking at that data, I really have to summarize that hybrid ablation is and will remain more invasive. We will never be able to compete with endocardial catheter ablation here. And I don't wanna appear that this will take place one day, but it is superior in this challenging patients in restoring sinus rhythm. The complications rates are not significantly increased, but it's logical to me, if you involve a more invasive procedure or a more invasive approach, that your complications rate will be higher. Is this acceptable? This is always something that we try to evaluate in our guideline committees, right? We look at the benefit-risk ratio, and that's absolutely in favor of this approach in non-paroxysmal AFib. So, yeah, it reveals favorable risk-benefit ratio. I think this is important to say at the very end. So, before you say I don't do anything to this patient anymore, or I repeat my catheter approach for the fifth time, consider hybrid ablation. Thank you. and the audience wants to come on the microphone. I'll start with a question. Can you all just speak about what collaboration looks like for these hybrid ablations between CT and EP and what is the ease of getting these procedures approved from an insurance standpoint? I'll take a stab at that. Is this on? So in our experience at Corwell, when we first started this program, essentially most referrals come from the EP doctors to the surgeons. We would send the patient to the surgeon. The surgeon would say, yes, no, can I go through risk and benefit? And then we would try to do a procedure in the same day or two days apart for one hospitalization. It became, there were some insurance barriers, but more recently, we have not encountered those. But trying to get the surgeon and the electrophysiologist schedules to coincide on the same day became an insurmountable barrier. So that's why we started staging them 30 days apart, which had some benefits. It was two hospitalizations, two general anesthesias, so there were some downsides to it, but logistically, it just became possible for us to do it in the same time. So you can ask the question. Prabhat Hibbar, EP from Little Rock, Arkansas. I have a couple of questions. The first question is, I would like to ask the panelists, what is the anticoagulation strategy after you clip the left atrial appendage? Do any of you stop anticoagulation at any point, or do you just say there's no data, we don't know what to do? No, based on the LAOS-III trial, there is a reduction in the stroke rate, but you still have to continue an anticoagulation, so that's my usual practice. Yeah, and I'm the rebel here again, because we see it a little different. I mean, the LAOS-III trial, the effect on stroke reduction was in addition to oral anticoagulation. Now, how do you interpret that? It's difficult. We usually do that on an individual base, and I'm very honest to the patient and tell him, according to the guidelines, we have to continue. But realistically, I think this is really, you cannot compare the EP guidelines here necessarily with the hybrid approach, because we always, at least not in convergent necessarily, in convergent plus, yes, but we always target the LAA, and if the CHATS VAT score is low, patient is in sinus rhythm, then we usually stop oral anticoagulation after three months. Thank you. My second question was about the article that came up in Europace last year where they compared PFA versus convergent procedure, and they said there's no difference. I'd like your opinion on that article also. That study, you know, I review it. I mean, there was no difference, but they use historical controls, so again, if you look at these single-center studies, you know, retrospective data, you will see, actually, there was one nice slide showing the randomized trials, you know, outcomes for the convergent, which was around 66%, 65, and the single-center studies, you know, it's like 20 points higher than that. So I will take that data with a grain of salt. I think we need really a randomized study to show if it's really benefit or not. Yeah, no, I agree. My concluding slide was we really need to see, you know, a meaningful-sized randomized trial of hybrid versus PFA. I think more in the long-standing persistent group than the persistent group. So we'll take one last question. Hi, I'm Rajvi. I'm a physician assistant at Sutter. We've been seeing some places where we're doing the convergent procedures, where we do the endocardial first, and the epicardial second, swapping the stages. Have you seen that? What are your experiences, and do you see a benefit with one approach versus the other? The question was which one you should do first? No, if it's trans-centers, you know, do the reverse. They're doing it reverse. Endocardial first, and then epicardial. Yeah. What would be the reason to do that? What's your rationale? That's what I'm gonna learn. Right. Yeah. I'm seeing at some centers where, including ours, where we have been seeing some patients having the PVI portion first, and wanting to see if you guys have seen these, if you've experienced it, or if you theoretically see a benefit in certain patients to have the endocardial approach first. I think one big advantage of not doing it reversed is just for my EP really being able to validate what I have done up front, and I'm not, I can test epicardially, but not with your potential tools, right, not as sophisticated. So this is why I'm also in favor of the staged approach, actually, besides being a nightmare doing it on one day logistically, but you really have the opportunity to have consolidated lesions there, or see the gaps much better than if you do it right away. If I clamp the pulmonary veins and you make a map, you probably have an isolated vein, although I have no, if I only clamp them, no ablation, you already have a, so reversed, I don't think, I wouldn't see a good reason for it, actually. And because the pericardial reflections vary so much from patient to patient that the epicardial portion the surgeon does is not as reliable. That's why we do such a good job afterwards going in and touching up. Sometimes we have to do very little, sometimes we have to do more. So if the epicardial portion was very reliable, like a surgical PVI, then that may make sense, but it's not. So I think the standard way has advantages. John Fontainefield, Florida. Relative to complications, any of you can comment, have you seen or believe that the stiff left atrial syndrome might be associated with this convergent approach? And being that you also probably have patients who had procedures done that failed, and that's why they're coming to a convergent procedure or surgical intervention. So given that, what do you think about the incidence or the occurrence of stiff left atrial syndrome with this scenario? Thank you. Go ahead. I guess it's not only because of the extensive ablation, but typical population that goes for a hybrid ablation, it's like those that have been already ablated endocardially. It's really like a evolving problem that has failed one ablation, has been antirrhythmic medication, patients have an atrial myopathy, extensive fibrosis. So I mean, I don't know it's only because of the convergent procedure. I mean, I think it's just because of the previous ablations. That's what we see also in after four or five ablations and extensive linear ablations with endocardial approach. How do you evaluate a patient for the possibility of developing that complication given that you're being asked to do a convergent procedure perhaps? I mean, in my practice, when I'm doing a re-redo procedure and I see that there is an extensive fibrosis, I try to limit the ablation because I think the benefit has reached to an end point pretty much. And I try not to do more. I mean, for that reason particularly. And again, doing more ablation also, it's not probably gonna be of any benefit anymore at some point. I think it's a really important question. I think it's a broader issue though for ablation. I think in some ways, because the surgeons aren't really going to attack too much of the anterior wall. And I think essentially the posterior wall's fixed in terms of its contribution to mechanical function. I don't have any concerns about posterior wall isolation or PV isolation. But I think it's actually gonna be more the electrophysiologist than the surgeon. You know, when they start isolating the back wall and posterior and pulmonary veins easily and patients come back with recurrence, particularly with PF and it's so easy and so quick to land big lesions, I think that the stiff left atrium might become a concern. Now, I know there's data to suggest that the architecture of the atrium is better preserved with PF than RF. But I don't think that data's strong enough. So I share your concerns about the stiff left atrium. Yeah, thank you. And I'll just add, in our experience, we have not seen, by just doing the posterior wall and the veins, patients come back with severe diselic dysfunction or staph atrial syndrome. I think it's because the anterior wall is preserved. Yeah, that has been studied, by the way, in our surgical population a lot because we were afraid of, I mean, we attempted to make the box as big as possible and we said, okay, shouldn't we keep it rather smaller? Do we create an isthmus again if we make it too big? So we had a lot of MRI studies with what do we do with a MACE lesion set, which is, in principle, a box. And it's exactly how you said, it's so fixed. The posterior wall is not really moving even in a healthy atrium because it's fixed. So your contractility that you preserve with the ablation is coming from outside what we do in a conversion procedure or in a box procedure with a TT procedure. I wouldn't be too afraid to harm the patient with that regard, to be honest. I did notice a very low incidence of pericarditis also. So that would support what you're saying. Yeah. Unfortunately, we are over time, but thank you to the speakers for an excellent talk and thank you to the audience for your participation.

hybrid ablation

atrial fibrillation

HRS 2025

epicardial techniques

endocardial techniques

CONVERGE trial

pulse field ablation

cardiac surgeons

electrophysiologists

AF management