Okay, everyone, if everyone can have their seats, I think we're ready to start this late Saturday afternoon session of Heart Rhythm 2025 in San Diego. Thank you, everyone, for joining. So, if you have not already done so, please download the Heart Rhythm app and scan the QR code. You can submit questions for this session through the app and using this QR code, or I think we'll have time for direct questions on the microphone in a small enough group that that's possible as well. So, today's session will be on pulse field ablation, maze mapping, or mania. We have four interesting talks. The first two are sort of a pro-con talk, not quite a debate format, but mapping or no mapping for PFA, AFib ablation, and the last two talks more on ablation beyond pulmonary vein isolation, posterior wall, and maze ablation. So, with that, I'll invite Dr. Julian Chun from Frankfurt, Germany to present the first talk, Mapping is Not Required for PFA. So, I try to bring up my slides. Dear Kevin, dear Paula, dear colleagues, ladies and gentlemen, it's my greatest pleasure to present today at HRS meeting on, yeah, it almost feels like a debate, even though it's not supposed to be a debate, and I'm definitely the bad cop, because I will convince you why mapping is not always required, my disclosures. And of course, to ask and answer the question why mapping may be required, I thought there are certain good reasons to do it, because typically, it used to guide our PV isolation procedures, and it was basically introduced to improve safety and to reduce fluoroscopy times, and also to help to understand mechanisms of atrial tachycardias, and maybe also mechanisms of atrial fibrillation. And my personal journey started more than 20 years back with the so-called double lasso technique, and we combined 3D mapping with electrical information, guiding our point-by-point RF ablation, encircling ipsilateral pulmonary veins, and this has been more than 20 years ago. What has changed now in the year 2025, and looking into most recent European era and HRS Asia Pacific consensus statement on catheter ablation, still pulmonary vein isolation, is basically, and remains, and has remained, and not changed, the cornerstone of AF ablation procedures, and all additional ablation targets at least have been classified of areas of uncertainty or even should not be performed. And therefore, I think it's very straightforward and very simple, because for an index pulmonary vein isolation procedure, it should be very, let's say, straightforward and simplified, and it does not need too much of boom, boom, and bang, bang, and nice and beautiful images, which in the end will bring us to the same goal, the best pulmonary vein isolation. This session today, of course, is about pulse field ablation. The pulse field ablation is the energy source which is its type at this point in time, and we all know that an electrical field is created, and depending on the recipe of the electrical field, different pores are created, and also reversible, but also irreversible electroporation may result, and the idea is to use this fairly wide zone, this broad zone, this therapeutic window to create a non-thermal, but still irreversible electroporation effect. There are many, many devices around, and I'm sure you have seen plenty of them in action during this course of HRS. I will primarily focus on our experience using the Ferropulse device, and I would like to introduce to you our so-called 5S study, which should save simple single shot and using sedation as a strategy for a best pulmonary vein isolation. You can see here, what we do is selective angiograms, different configurations of the device, a basket configuration, a flower configuration, and then to assess local contact, we push the device to the vein based on our baseline angiograms, so we have a very good idea in seeing the champignon-like configuration that there is good contact to the tissue. The proposed energy, or the relation workflow, proposes four by two applications, and you can see here, four baskets, four flowers, and they should be rotated, and based on, yeah, fluoroscopy, for instance, and you see here, there's the wire, if you see it three down, two up, and you simply do rotate three up, two down, and this enables something of 30, 60-ish degrees rotation and adequate overlapping in a typical scenario. Following this idea, we introduced and we published our 5S study, and you can see here, after an initial validation phase and the streamlined phase, there was a very, very short procedure time, a small standard deviation, despite of six different operators from de novo, basically, and a fairly good safety profile, and we just recently presented as a late break at the German Cardiac Society meeting our extended experience, and you see here, still a very favorable skin-to-skin procedure time, low fluorodose, as you can see as well, and also, and this, I think, is most important, a very benign safety profile for a standard PVI procedure. So the question still is, does it, and what is the potential value if 3D mapping was added as a routine standard to this type of IAF ablation procedure, and this is work from Switzerland, and they compared mapping versus no mapping, as you can see here, and what came out is basically that the success rates are not similar, but all procedural metrics basically have been prolonged, even though the reconnection, but also re-procedure rates are basically the same, and therefore, the colleagues, they concluded that the use of the pent-spline system with no mapping was associated with a significant decrease in procedural characteristics while IAF recurrence was not different. Looking into re-mapping studies, and yeah, more or less a real-world scenario, there's work from De La Roca published, and they found also in the propensity score matched comparison that the Ferropulse device versus contact force and mapping over cryo was gold medal, silver medal for the cryo balloon, and bronze medal for mapping, so therefore, the straightforward approach may be okay for a good pulmonary vein isolation procedure, but can you say, wait a minute, there's data from the redo, from Daniel Sher, from the manifest data collection, and yes, you're right, in this initial real-world experience, multi-center real-world experience, there's definitely room for improvement with regards for durability of pulmonary veins, but you should keep in mind operators, they did use the proposed eight-application protocol. Looking also into pulmonary wall, also from the manifest redo data collection, and we will have a different talk later on, therefore, I don't want to spend too much time on this, but also here, we could and had to learn that durability of pulmonary wall isolation was a little less than 50%. On an acute level, of course, it looks beautiful if you do it, but we know over time, reconnection even with pulse-field ablation may occur, and this is also data from the manifest, and you see here that in patients with PVI plus pulse-field wall versus PVI only, there was no difference, so maybe it is not an empiric must for all, even if we use pulse-field ablation, but experience matters, we all know this, and this is, therefore, maybe not too surprising that a fluoro-guided PVI in experienced centers did now lead to a non-inferiority, again, using pulse-field compared to cryo-balloon ablation, and this study even met very, very narrowly superiority, even though I think this needs to be replicated and shown in larger trials as well. What else did we and could we do in order to improve durability of our lesions, and we came up with a configuration which we call the OLLIF, and you see here, we do slide a little bit in the little smaller basket, maybe OLLIF configuration, and do apply two additional applications on top of those, as you can see here, and in total, 10 applications per vein, and this did lead, in summary, to a significantly lower rate of reconnections in our center in patients who came back with recurrence. For safety reasons, we had no signals that increased hemolysis could have impacted the safety profile. Of course, and I'm sure you will see a lot more and have seen many, many beautiful signals on additional imaging, such as ice, maybe, or also the Farah view and the Opal environment, and also, we use it, and it's nice because you can nicely see and rotate the device in order to confirm a good overlap of potential lesions, so it's good and nice to see, I have no doubt, and this is also a different technology which also combines high-density mapping with a PFA balloon, and also this, there was a beautiful live case at this meeting, but still, overall procedure times, fluoroscopy times, and metrics are still not in that range if you compare it to, let's say, a straightforward, simplified procedure, and therefore, I would like to summarize. 3D mapping is nice, it's beautiful, but it prolongs procedural metrics. In contrast, the OLLIF concept easily improves PVI durability. Empirical postural isolation, even though it's been widely used, still has to prove, in a prospective fashion, and control its benefits, and of course, maybe I will have a different opinion once we have a randomized control trial which was comparing and proved the mapping benefit versus, maybe I call it a standalone procedure, and therefore, ladies and gentlemen, I think, and I propose, keep it simple. Thank you very much. Thank you. Thank you very much, Julian, for this nice presentation. If there is any question from the audience, please come to the mic. In the meanwhile, I would like to ask how confident are you that your lesions are really overlapped and you are not leaving gaps, and what do you do for your Redux? Are you using mapping for Redux, or what's your approach? Yeah, of course, I think, of course, it is important to create those overlaps in order to have the truth, certain for lesions, then more, maybe, angio, osteo, and even more, olive level, and this helps, at least in our experience, to increase the rate of permanent PVI in patients who came back with AF or AT recurrence. And the second question, of course, is in a second, in a Redux, or a third procedure, of course, it's a completely different scenario, completely different scenario. In this scenario, of course, we need to understand, first of all, if there was an atrial tachycardia, we need to understand the mechanism of the atrial tachycardia, but again, here, it's nice to have 3D mapping and nice colors, but we should not forget about our standard and very established, let's say, analyses of electrogram and activation and the tremor nerves, et cetera. So I believe a typical macro-rental tachycardia, which is predominantly the case in a flutter after a PVI, you can understand, even though you don't have 1,000 or 2,000 or 5,000 points. You can understand this tachycardia with 60 good points, I am sure. With regards to what is the best strategy then, of course, this is something which is completely, unfortunately, unclear, at least to me, and therefore, our strategy is to understand the substrate, and we go for a concept of linear lesions, which we try to do durably, block, based on, let's say, individual substrate or characterization, yeah. So I am a mapper, but maybe I don't need to be. Maybe it's historic that we map every PVI, but I guess one concern I have is the mapping, I'm not really checking for PVI after PFA because that seems to be pretty universal, but I worry about making my lesions too close on the posterior wall and creating substrate for flutter. So how do you address that if you don't map? Do you empirically do posterior wall isolation? Do you have other ways with ice or even fluoroscopy where you're assessing how close your lesions are together? Yeah, of course, we have a very rough estimate based on the floral, on the flower configuration on the left and the right upper vein, for instance. However, and this is, I think, the major part in our clinical routine, we have now almost in all cases, almost in all cases switched to the 31 millimeter device rather than 35 millimeter device. And we feel this allows or this allows for not too close, let's say isthmus along the roof. But of course, this cannot always be excluded and here we lack some information. Thank you, Julian. So it is my pleasure to introduce the next speaker, Dr. Andrea Sarkozy from Brussels, who is gonna talk and is gonna tell us about how mapping is an integral part of PFA. So, dear Kevin and dear Paola, it's a real pleasure to be here. And so, it did sound like a debate. And I know that Julian is capable of giving excellent talks and is capable of convincing you of everything. So, I have been knowing Julian for 20 years. This is when we got to know each other in 2004. This is how he looked like. And at that point, he has been using... It's very funny that he brought the same publication. So, he has been... When everybody was putting one lasso electrode to do the lasso catheter, to do the pulmonary vein isolation, Julian was so interested and so curious about mapping that he put even... They developed the double lasso technique and they put another bunch of catheters still in the right-left atrium. And that has changed in the last 20 years. So, now, Julian is only putting one catheter or two catheters maximum in the heart and then doesn't map anymore. So, sometimes, it's a big surprise that the catheter, instead of the right superior pulmonary vein, is in the RVOT. So, I think just to give another perspective about mapping. So, every intervention has advantages and disadvantages. I would only like to talk about, indeed, in the first part of the presentation, about the first pulmonary vein isolation and the role of mapping in these procedures. So, it has advantages. We are going to better understand the anatomy. We have a way to have contact assessment, lesion tracking, normally fluoroscopy reduction, because that's why 3D electroanatomical mapping has been developed, and the versatility to map complex substrates. The disadvantages are that, indeed, there is an increased procedural complexity, increased procedural time, there may be sheet exchange if it's not an integrated system, and, of course, the increased costs. Now, I think we are sometimes mixing mapping and imaging, and I know we are in the U.S., so I'm not going to talk much about intracardiac echo, but, for me, it's not really a mapping technology in the way that it's not capable of electrical mapping and lesion tracking, and so I would just like to talk about the 3D electroanatomical mapping, either integrated, meaning that the same catheter is doing the job, or non-integrated, when an apart catheter is being used for the mapping. And, indeed, this beautiful article from Julian has already been shown, and these are the two systems currently available commercially, which are being used without 3D mapping, so the pentaspray catheter and the post-salad catheter. Now, is mapping essential? So how can we answer that question? So, for that, we would like to have direct evidence, meaning that if there would be a randomized control trial showing that it's superior, then we would be happy, but, of course, this is not available yet, so we need to rely on indirect evidence. Now, we can look at observational comparative data where the procedure efficiency, efficacy, and safety outcomes and PV reconnection rates are compared between patients who underwent pulmonary vein isolation with a single-shot device, with first PVI, with or without mapping. And I would just like to mention, because we talked about it a little bit, and I find it very important that redo-AF ablation and complex arrhythmia substrates are, for me, a different category. So, fortunately, Julian has shown this data already, but, of course, the interesting part of these trials is always in the details. So, in these studies from Switzerland, it's a two-center study. Indeed, the procedural time was prolonged, and there was no difference with using adding mapping with a non-integrated system to the pentaspray catheter PVI. It did not make a difference on the outcomes. However, I would like to mention that the follow-up was 9 months. So, maybe if we would have gone a little bit farther here, there would have been a difference in the outcomes already here. And also, that 1 out of 10 patients, so 9% of the patients when they underwent mapping, they already had acute reconnection. And these patients were, of course, rehabilitated. I think this is very impressive and interesting data. So, also, I was very surprised to see that using a 3D electron-antimem mapping system, the fluoroscopy time was increased with almost 40%, which is, for me, very unusual. And I would like to one more time mention that it was a non-integrated electron-antimem mapping system. So, that means that there was sheet exchange and the lesions were placed not with the same system. Now, there is another with the pulsary catheter. There is another very small study from Dr. Guna Vardena with the pulsary catheter. Again, looking at this observational data, looking at single-center data only at 35 patients and trying to optimize the workflow. But what I found interesting in this study is that she had a phase 1 TEMP patient's procedure when mapping was together with a non-integrated system, with the N-site system was used with the pulsary catheter. And in these patients, the first-pass isolation rate was 86%. Then, in the second phase, after the learning curve, the first 10 cases, only fluoroscopy-based pulmonary vein isolation was used. And look at the... In the phase 2, based only on fluoroscopy, but the acute PVI in this patient was only... First-pass isolation was 81%. And finally, in the optimized workflow, again using the 3D mapping, it was 100% first-pass isolation. So, again, we should keep in mind that this is a non-randomized single-center study. There is a non-integrated 3D electron mapping system used, only with 35 patients, and there was no follow-up. Now, I don't like that much single-center studies, so I always like to turn to the large registries. For example, the Euphoria, which was published by Julian's group. And in this study, just to mention that 33% of the patients were ablated with a single-shot pentasprine cancer, first PVI, with electron-atomic mapping. And who were the people who used this the most, electron-atomic mapping, during the procedure? The most experienced operators, with more than 5 years of experience. To me, this is an interesting data that may show something. Now, we already talked about the manifest. Julian was mentioning it. So, this is the other large registry, the PF part of it, so the 1,700 patients registry. Again, one out of three patients underwent an ablation with a pentasprine cancer, with the use of 3D mapping. And one out of three patients had also ICUs. Now, what was very important data from this study, that at the redo procedures, they looked at the centers, where the PVI durability per pulmonary vein basis was more than 50%. These patients, these centers, had better outcomes. So, the connection, as Julian has also mentioned, is extremely important. And he has shown this study from Dr. Sher, the manifest redo study, when they went back to look at the real-world data of complete pulmonary vein isolation, the durability, PVI durability. And what Julian forgot to say about this study is that the use of any form of imaging or mapping at the initial ablation was associated with a higher PVI durability, so 47 versus significantly 37%. So, this is indirect data, but I think it's a very important data to keep in mind. Also, Julian has shown, as opposed to the ADVENT, the single-shot champion study. Again, I think it's a little important detail to look at, that in this study, the protocol was so that 25% of the patients who underwent, by very experienced operators, more than six months of experience, so more with the long experience with the pentaspine and cryo-catheter, they underwent 25 first patients underwent mapping. I think this new device learning curve or any kind of learning curve, it's very important to keep this data and option in mind, so when we are starting with a new device, even in experienced operator hands, that it may be useful first to look at the, do the procedures with mapping. This also came up, I am very happy that somebody asked this question. So, this was, for example, first after mapping of the first PVI procedure in a small atrium. This is what we see, so the incidental conduction block of the roof line because the two circles are too close to each other. Another example of how useful mapping can be, this is the integrated system. This is, for example, based on fluoroscopy, Julian has shown very nicely the little two, three splines up and down. This is when the operator was not seeing the before rotations, so ready to develop, ready to after rotation, the third 60 degree rotation to perform the second ablation, thinking that there is overlap as it is here. Well, there is, it was a 72 degrees of rotation and the second application, actually the third one, was exactly in the same place as the first one, so there is obviously, there is a big chance that there will be some gaps remaining in this region. And finally, just a very short note that I cannot imagine how you would want to do these procedures in this kind of very complex arrhythmia substrates and either when we see a patient presenting with atrial fibrillation but being in flutter, then over flutters, or after the redo procedures and pulmonary vein isolation. So in conclusion, I think it's currently not proven yet that routine use of electrons when mapping our eyes improves efficiency, safety, or efficacy of the first single-shot PVI procedures. I think the observational data suggests that PV reconnection rate may be lower with the use of eyes and 3D electron anatomical mapping, but we still have to prove if this translates to better long-term outcomes. In our center, because we are also, I have to be very honest, we have been in the last years not using, last two years not using in routine 3D electron anatomical mapping, but we do use it if there is an inexperienced operator or where there is a new device. I think for the learning curve, it's very important in the first five, 10 procedures to use the electron anatomical mapping which is not non-integrated. And finally, I do believe, strongly believe that electron anatomical mapping is recommended in case of complex arrhythmia mechanisms or substrates just like as atypical flutter and AF fibrillation. Thank you very much. Thank you. Thank you for a great talk. We'll open to any questions from the audience. I'll start with a question. So if I am gonna map, is it okay just to map with the penicillin catheter or with the lasso or do I need a high-density mapping catheter in addition? In my opinion, I think it depends on the procedure. If it's a single-shot PVI procedure, I agree. We need to keep it simple. So if the patient is in sinus rhythm, I would suggest that we are mapping with a pentaspine catheter. We don't use high-density mapping catheter. If the arrhythmia substrate is complex or in case that we do non-PV, so extra PV lesions, then I think 3D mapping with high-density catheter may be useful. Maybe if I can also ask one question and give one comment. Just one. First of all, as a comment, you referred to the Euphoria data and mentioned that the most experienced operators used predominantly 3D electronic mapping. This is correct. However, we also found and were surprised to understand that those operators had the most numbers of complications. So therefore, there's a disconnect on this. And therefore, I'm not sure if it automatically needs to, will lead to a safer procedure just to connect 3D mapping. And the other, and this is my question, would you consider now, based on what you have been nicely exploring and explaining, to use 3D mapping in routine cryo-balloon cases? No, I think it's, so we are talking about PFA. This is a PFA session. And we were talking about PFA being used with 3D mapping. So I would not consider, I am very well aware of your very nice data, actually, showing it does not improve outcomes. But we are talking about, not a balloon technology, we are talking about another form of olive basket, whatever, flower. We are talking about the pulse select. We are talking about caster handling, including very fine movements and rotation based on fluoroscopy. I think, so as I said, in our routine now, what we do, if, for example, fellows, I am very well aware of that, that it depends on which high volume center you are working or not. But in case of, I think, inexperienced operator, or when you use a new device, I think it's very useful to do in the first cases, in the learning phase, 3D mapping. Yeah, I agree with that. Maybe a question for Julian. If you are not using mapping and you get a spontaneous atrial flutter, or you induce an atrial flutter, how do you manage that? Yeah, it's a good point. Of course, those are the patients, typically, we should not be assigned for, let's say, single shot technology. However, if there was a typical flutter, of course, we can also do, even though it's not, let's say, recommended, to do a CTI flutter, even with a single shot device. Basic entrainment maneuvers is also possible. And also, therefore, you will be surprised how often you can terminate and ablate successfully macroentotopic audio. Great, thank you very much. I'd like to ask a question. Actually, I have a comment. Do we have time? Yeah, sure. So, I think, look, if money wasn't an issue, we would map everyone. I think so. Because you do get more information. In my experience, and I think most of your experience, too, about 20% of the cases, if you stimulate, you will get some kind of organized rhythm that's likely to come back again. So, I do think, like, you know, the real question is not whether mapping is helpful. Of course it's helpful. It needs to be balanced against how much more it costs and how much more time does it take. But if you solve these two issues, of course mapping is a good thing. And the second thing is just the comment about the cryo, the balloon technology versus, you know, the pentaspline. These are two completely different approaches. A cryo is a truly single-shot device. The pentaspline is not a single-shot device. It's a catheter that you can, you know, you can put in the vein and apply and get, like, you know, I don't know, 50% of the vein, then you rotate a little bit more. But you don't really know. Even if you're the most experienced operator, you don't 100% of the time know that you have a nice overlap. Likely you do with more experience. But there is a clear distinction between a true single-shot device to the pentaspline, in my mind. Thank you. Okay, so we'll move on to our third talk. That definitely turned into more of a debate, so that was great. So now we're going to move on to ablation beyond the pulmonary vein. So the first talk is from Atul Verma from McGill University, titled, Should we now do PBI plus posterior wall for all patients with PFA? Great. Thank you very much. And just while we're waiting for the slides to load here. Okay, perfect. So the question is, should we do posterior wall in all patients with PFA? And these are my disclosures. I mean, we can start at the beginning. Why do the posterior wall at all? Why did we even start doing this? Well, embryologically speaking, the posterior wall comes from the same tissue, the same extensions as the pulmonary veins. So if you believe that the pulmonary veins are the major source of triggers for atrial fibrillation, it also makes sense to believe that the posterior wall, which is, in effect, the same tissue, an extension of the veins, embryologically speaking, that the posterior wall, too, should be addressed in PBI procedures. And if you think back to the original MAZE procedure, the MAZE procedure always isolated the posterior wall in addition to the pulmonary veins. So this was not something new that we just suddenly invented. This goes back way back in time. And certainly, with PFA, it seems like we have eliminated the problem of esophageal injury. There's lots of preclinical data showing that you can place a PFA catheter right over the esophagus, ablate, ablate, ablate, ablate, and yet when you sacrifice the animal 30 days later, you do not see any evidence of esophageal injury. Now, having said that, is it that simple? Because, in fact, we're now starting to see publications that when the animal is sacrificed after a few days or after just a couple of weeks, it is actually possible to see some esophageal lesions after PFA application. Now, is this unexpected? Are we meant to panic about this? No, it's not unexpected. We should have expected that there would be some esophageal lesions. But the reason why we don't see them at 30 days is because, unlike thermal ablation, IRE, electroporation PFA, does not destroy the extracellular matrix of the esophagus. And the esophagus is built to regenerate. So as long as you have an extracellular matrix with intact vasculature, progenitor cells are going to come in, they're going to repair the esophagus, and then after a period of about two weeks, the esophageal lesions are gone. Why does the esophagus repair itself? Well, just think about all the hot fluid, sharp things that you place in your mouth and swallow all day. The esophagus has to repair itself after it's done all those things. Furthermore, even a small layer of fat can deflect significantly and decrease the concentration of field on the esophagus. So even if you're delivering a full-strength field in the left atrium, even a couple of millimeters of fat will substantially reduce that load. So I just wanted to point that out, that I'm still not worried about esophageal injury with PFA, but the story is a little bit more nuanced and more complex than just saying that it's not possible to get lesions. So why do the posterior wall? Well, I think one of the things that has already been mentioned by our two previous speakers, so I'm not going to spend a lot of time on it, is that as you do PFA with these large catheters, it is very easy to create WACA lines that come so close, and this is seen here in the very bottom image, if I can get the arrow to come, in this bottom image, the lines come so close that you're now leaving a very small channel, which potentially could be prorythmic. Now the key word there is potentially. There is actually no well-done study to prove that leaving that small little line is in fact prorythmic, but we just assume that it's prorythmic. And so we say, okay, well, as long as we're not having to put too many additional lesions on the posterior wall, and since we know that it's safe to ablate on the posterior wall, why don't we just do it? And this is some data from the Swiss group showing that the total number of PFA applications for the posterior wall was about 20. And then if you add that to the 16 lesions that they applied for the pulmonary veins, you know, that's about 36, 40 lesions, and that's certainly below that threshold of about 50 lesions, which starts causing hemolysis with some of the catheters, in particular the variable circle and the pentaspline. There are other catheter designs where you can go 64, 128 lesions and you don't have to worry about hemolysis. But the point is that depending on the technology that you choose, you can actually do the posterior wall without necessarily exceeding that hemolytic threshold. But the question then becomes, if you do the posterior wall with PFA, is it actually durable? Do we actually get a good result? And again, this is the Swiss group's data, which I think was the best data looking at this question. And when they went back into redo procedures, they did pulmonary vein isolation and posterior wall on everyone, they actually found that 85% of the patients had durable posterior wall isolation. So it seems like if you do the posterior wall correctly with the tool that you are choosing, you can actually end up with a durable result. Now a lot of this data was using the pentaspline catheter. And you might say, well, what about the circular gold arc, the pulse select catheter? Given that it's over the wire and it has a nose, can you really do posterior wall? The answer is yes, you can do posterior wall. This is an example of one of my cases where I do use mapping systems to track the shadows of all of the lesions. And you can see that if you actually want to run that catheter clear across the posterior wall, it is very easy to do so. And at the end, you get a very, very nice posterior wall isolation in addition to pulmonary vein isolation. So we have now been doing a lot of pulse select cases. That number 200 is now probably outdated. We're closer to 300. But I just wanted to give you a small sampling of the first 60 clinical cases where I've been doing PVI plus posterior wall isolation in all patients. On average, it requires about 53 applications with the pulse select catheter. The LA dwell time is about 32 minutes. We are using mapping. And we are also using ice. So we do get to play with all of the expensive tools and toys, fortunately. And the fluorodose is relatively low. But we've also been measuring all of the hemolysis parameters in these patients. And if you look at that plasma-free hemoglobin, it's about 403 milligrams per liter or about 40 milligrams per deciliter, depending on which units you use. And translated, that means it's falling below that severe hemolysis threshold limit in spite of the fact that we are applying so many lesions. Now, in fact, there have been a number of meta-analyses done looking at the question of whether posterior wall isolation adds benefit. This is probably the best meta-analysis that was done by Prash Sander's group. And if you look here, it doesn't really matter how you do the box isolation, whether it's a single ring, whether it's two lines, a box isolation, whether you just go and debulk and ablate everywhere on the posterior wall, it seems like you actually do get a benefit in terms of overall outcome, particularly in the 12-month freedom from atrial arrhythmia. And then, of course, there was the CONVERGE trial, which was a hybrid PVI surgery trial where basically the posterior wall was done surgically under direct visualization to get a fully durable result. And you can see here that when they did the CONVERGENT procedure and added the posterior wall, the success rate in these otherwise chronic, persistent atrial fibrillation patients was significantly better with posterior wall isolation than with just PVI alone. Now, this data has been shown, saying that in the manifest PF registry, and remember, this is a registry, it's retrospective look at the data, so even though there's Kaplan-Meier curves, this is not a clinical trial, it seems like adding the posterior wall doesn't really add that much to success. However, you need to look at the details. And look at these details. For example, in the patients who got posterior wall isolation, they also got many more mitral lines. They, in general, received more lines and more additional ablation sets. And we know, whether it's with PFA or whether it's with RF, that getting durable mitral lines is challenging. PFA has not solved this problem. And so it's interesting that in the posterior wall ablation group, they were also doing all kinds of other things which may not have been durable, and therefore may have been taking away from the success of doing a pure posterior wall isolation. Well, the real elephant in the room is the Kaplan trial. Now, Kaplan, of course, was a radiofrequency trial. This was not a PFA trial. But it's just as relevant because, frankly, the lesion depth that you're getting with your current generation PF systems is no different than with close protocol RF ablation. So when people say, oh, we have to repeat all these trials with PF, and all these trials are useless, they're wrong. But you can see here that with the Kaplan trial, there was no difference in persistent patients who received posterior wall isolation. Having said that, the median duration of atrial fibrillation in these patients was only about five months. So yes, they were persistent, but most of them were early persistent. If you look at more truly persistent populations, there are actually some very interesting promising results of using pulse field ablation to isolate the posterior wall in persistent AF populations. And some of these results are actually starting to look pretty good. But these are all single center, non-randomized trials. These are simple trials. Having said that, the STAR-AF3 trial will be reporting next year. We have completed enrollment. We're in the follow-up phase. This was a more persistent AF population than Kaplan. We are comparing three different strategies, one of which includes isolation of the posterior wall. Thank you to all the sites who finished enrolling the 600 patients. And we can expect results on this in fall of 2026. Again, it's not PFA, but it's very well done RF. And I think the results are going to be every bit as informative. So in conclusion, I think posterior wall isolation may be a good strategy for patients, particularly those with persistent atrial fibrillation. With PFA, the procedure certainly has become easy, avoids serious esophageal damage. It does require extra lesion application. So depending on your technology, make sure you understand the hemolysis limits. And finally, effectiveness has yet to be proven in large-scale trials. Thank you very much. Thank you, Atul. We are looking forward, really looking forward to see the results of the STAR-AF3. I think that to be on time, we should move on to the last speaker. And then if we have time, we can leave the discussion for later, okay? So it is my pleasure to introduce Dr. Ilad Anter from Israel. He's going to talk and he's going to tell us whether if it's time to bring back the catheter-based MACE procedure with PFA. Thank you very much. I'm glad to be here. Okay, so my task is, is it time for coming back to the MACE procedure, but with catheters? So what is the challenges we have today? And the real challenge is the status quo. So catheter ablation has emerged nearly 25 years ago for AFib, and we've been doing PVIs. However, we haven't really changed patient outcomes significantly, and I'll show you some data about it. What we have done is that we improved the safety of the procedure, we improved the efficacy of the, the efficiency of the procedure, but the efficacy is relatively unchanged. And the, the, or at least the discoveries, the scientific discoveries have not matched so far the technological advancements. And if you look on this original study from Mishela Sager, describing the results of PVI in patients with paroxysmal, and some actually persistent atrial fibrillation, if you actually read the, the results section, the outcome was not so much different from what we have today, 62% success rate, and this is late 1990s. Now this study have been shown again and again in this meeting, this is from 2BS. When we looking on patients with paroxysmal atrial fibrillation, nowadays, like with current technology, the pentaspline catheter, when we monitor them closely with loop recorders, we can see that the outcomes are relatively similar to what Mishela Sager described 25 years ago, 62%. So the problem is that, or at least the challenge is not in, in obtaining PVI. The issue is that PVI, or anything else that we have been doing so far, max, you know, max our outcomes around this number. And this is from Atul Verma, and the Star AFM study showing that it doesn't really matter what strategy you use, PVI alone, or you guide electrograms that are abnormal, or you just do empiric lines, the outcome is fairly, outcomes are fairly the same, around 60%. This is my own study that I published with the Afera system with persistent patients, and we've, we showed that the outcomes with, you know, with a very advanced catheter that can also map is about 73%. But don't forget that we used Holter monitorings every month or so, and if you, if we were to put loop recorders and using Jason Andreda Circa dose study, we know that that will take this outcome probably about 10% down to around 60%. So we are stuck in the 60%. Maybe for paroxysmal we can get to 70%, but this is kind of like where we can go. Now you can say, you know what? You haven't done enough. We can do posterior wall. We can do mitral lines. We can do other things. But we have done it actually unintentionally. That wasn't part of the protocol, but you can see that in the investigation alarm that used the sphere nine catheter, substantial amount, 95% of these patients, the operator chose to do additional lines, but yet these are the outcomes. So why the maze worked? The maze worked because we targeted both triggers and drivers, and what the maze does, at least the surgical maze, it creates compartments where the, when the size of the compartment is smaller than the wavelength of the atrial fibrillation driver. And the lesion set is anatomically standardized. It's less dependent on electrograms and on mapping and on interpretation. It makes the procedure relatively simple, at least surgically. And importantly, the lesion sets also include the right atrium, not only the left atrium. Now this is a meta-analysis of a lot of patients from Ralph Damayano, and what he's showing here, look at the results after 10 years of patients with paroxysmal and persistent atrial fibrillation. After 10 years, they see the results that we see after one year. Yes, now you know, this is without loop recorders, but still, this is comparable to the most common way that we monitor our patients, and it's really good. And when you also analyze or sub-analyze the data based on patients that underwent only left-sided ablation versus those that underwent right atrial and left atrial ablation, or at least had lines in both sides, you can see that a right atrium adds a lot. And we don't do much in the right atrium. We do a CTI, but we don't do a lot of ablation for drivers or triggers in the right atrium. So what are those lines that they do in the MACE procedure? So the left atrium, it's pretty, I think, obvious to everyone. They isolate the posterior wall. They create a posterior, sorry, they isolate the pulmonary veins. They create a posterior wall box set. They do a mitral line, and they also connect the left superior pulmonary vein into the stem of the left atrial appendage. But interestingly, what they're doing in the right atrium is in addition to CTI, they create an SVC to IVC line, but two additional lines, one line that connects the right atrial appendage into this SVC-IVC line, and another line that connects the tricuspid annulus into this incisional line that they made in order to cut into the right atrium to do the procedure. So what changed? Why are we talking about a MACE procedure now in 2025, where we have so many better technologies that are pericontaneous? So there is a growing evidence that achieving roof, floor, and mitral lines and all the other lines we want to do can be done better with these technologies and can be done safer, particularly in regard to the phrenic nerve and to the esophagus. And the data I'm going to show you is the data that we have with the focal catheter, the large focal catheter, the lattice catheter, that is designed to do linear ablation as opposed to a pentaspline or a single-shot solution. And this is a study we published several years ago, and in this study, we used both RFA and PFA using this catheter, and we remapped a significant amount of these patients. And these patients were paroxysmal and persistent patients. But the bottom line is here in this figure here. You can see that in the redo procedures, the roof line was intact in 100% of the patients. And in the majority of patients, 91% of them, all the linear lesions we made were intact, and this included mitral lines, roof line, inferior line, CTI lines. So there are tools that are designed to do linear lesions that seems to be more effective and safer compared to the tools that we use until now. And this is just the first of them, this sphere 9. There are many more catheters that are going to come to the market soon that are designed to do safer linear lesions. So who should we consider doing a MACE procedure to? In my mind, at least, long-standing persistent natural fibrillation, patients that are coming for a redo procedure and have durable PVI, those that are coming for a redo ablation and have multiple ATACs or significant area with scar atrium, or just patients with severely enlarged left atria. However, there are challenges and there are considerations of doing MACE procedures, and what are they? First is the risk of overablation. Multiple lines that can be prorythmic, they can create an unnecessary scar and they can impact atrial function. Sinus node dysfunction has been reported in a substantial minority of patients undergoing the MACE procedure, and I can tell you that I have done several Cox MACE-like ablation procedure with PFA, and I have seen transient, at least transient, sinus node dysfunction. So we have to carefully think about it, and if we do decide to do it, we probably need to be more considerate of where we want to do these lines. There is a technical complexity to this, precise lesion sets, confirmation of block on all these lines, the heterogeneity of the tools across centers and the time-consuming, and there is lack of standardization and evidence. Obviously, we need an RCT to compare MACE to all the other strategies that we do in patients with isolated veins. So to conclude, standard approaches of PVA plus have reached, in my mind at least, their efficacy limit, especially for patients with persistent atrial fibrillation. I do think that the Cox MACE procedure is logical, it does make sense, and we nowadays have the tools at least to ask the question whether this approach is suitable for some patients. But in order to start doing this, we really need to test this strategy in a randomized study. Thank you very much. Thank you very much, Ilad. So there are some questions from the audience. Atul, this one is for you. Can posterior wall isolation with PFA really be considered equivalent to posterior wall isolation with RF, since we are essentially killing the endocardium rather than trying to create lines of block? Yeah, I mean, that's a very good question. There's been a lot of argument over this, like if you do a box versus if you do an encircling linear lesion versus if you go inside and you pummel the posterior wall, which is what we're doing with PFA catheters. But if you'll recall, I showed you the meta-analysis from Sanders, who looked at each and every one of those techniques. Now, of course, that was all with radiofrequency, but they really did not find a statistically significant difference between any of those techniques. So even though there are people who say, oh, well, if you do a box, there are lines, and can you really get block across lines? And the reality is that most people who are doing the posterior wall are probably doing a small combination of all of those techniques. So you may draw lines, you then check inside the box. If your box isn't isolated, you then put a few points within the box. So people are probably doing a bit of a heterogeneous approach. A question about posterior wall isolation with PFA. I've seen a lot of folks starting to extend it very low on the floor, almost down to the CS, and I guess maybe that's in line with debulking in a patient with persistent AFib. If you do that, two questions. One, do you need to check for atypical flutters, putting patients at risk for mitral flutter? And number two, do you have any concern about stiff leptatrium with all the extrapolation with PFA, or is that really an RF phenomenon? Yeah, good questions both. So there has been no definitive evidence published to say that extension of the posterior wall all the way down to the CS significantly improves outcomes. I know that Natale's group in particular has been quite keen on this, but they're still putting together their data and they're still putting together their numbers. But as of right now, there's really nothing more than just opinion driving that. Stiff left atrial syndrome with PFA is interesting because, again, you preserve that extracellular matrix. So yes, you do get scar. Yes, the muscle does die. But because you're keeping that extracellular matrix, there is a feeling that the walls after ablation are going to be more flexible than thermal scar. And there's some speckle tracking echo data to suggest that that is in fact the case. But you know what? PFA has only been around for a couple of years. So we've got to wait 10 years to see if the stiff left atrial syndrome comes. Thank you. Well, I think we are out of time. I think the speakers may be available at the end if there's other questions that folks want to come up and ask them. Otherwise, thank you, everyone, for attending. And thank you to the speakers and my co-chair for an excellent session.

Heart Rhythm 2025

San Diego

pulse field ablation

atrial fibrillation

mapping debate

posterior wall isolation

PVI

MACE procedure

ablation strategies