Chapters Transcript Video PCI in the DCB Era: To Stent or Not to Stent — That is the Question Dr. Heizer reviews the role for drug-coated balloon technology in PCI and stenting for cardiac patients. So I'm excited to talk to you today about um PC I and the DC B era to stint or not to stint. That is the question. And let's see, it's not clicking. Here we go. I have no disclosures. This is the outline of our talk today. First, we're gonna go into a little bit about the history of coronary interventions and how it's evolved um including stents and stent design a little bit and then we'll segue more into um D CBS or drug coated balloons themselves. And in a more focused talk, this is a sort of a neat artistic representation of the evolution of coronary interventions over the years. Um I got this in residency. I went to a TCT meeting and one of the books they had there um that they were giving away, had this illustration and I thought it was kind of neat, just sort of showing how um interventions have evolved over the years. First, it starts on the left, you see um balloon, angioplasty, then bare metal stents and then drug alluding stents. And then what our goal has sort of been is to have something that um either a bio resorbable scaffold or drug coated balloon is something that you don't leave in the artery. So you can turn the coronary arteries from what you see on the left to what you see on the right where you leave nothing in there. First, we'll talk about the history of coronary, angioplasty and stenting. So this slide is just to show you sort of some important dates in the historical timeline dating back all the way to 1916 when the term stent was first used. Um and then going on to the 19 sixties, 19 seventies and particularly in 1977 the first balloon angioplasty was done on A L AD and a 37 year old by what many consider as the father of uh modern angioplasty. And that's Andreas grunig and that was done in Zurich. And then it wasn't until about 10 years later that the first Coronary stent was placed by Jacques Puel as well as Ulrich Sigwart. And you can see the images of those interventions on the left. And interestingly um in the vascular space, stents were actually used much earlier than that. And it wasn't until un until later that coronary stenting was uh developed in the early days of angioplasty. Things were kind of rough to say the least. Um And it's known to some as the saga of the balloon. Well, there were patients um that the treatment clearly helped and it was life saving. We didn't really know how to treat patients afterwards, as you can imagine. Um doing a big intervention like that, it takes a lot of coordinations. You know, now we have very strict protocols with anticoagulation and things like that. Um But at first they didn't really know what they were, what they were doing in that regard. So um in one of the first trials published in New En New England Journal in 1979 and this was Dr Grunig as well as Ike Sinning, who you can see in the picture. Um There were only 50 patients, it was only successful and 32 of patients, 32 of the 55 required emergent bypass three with infarct during the procedure. Um And they realized quickly that they were going to have problems with one acute vessel closure and two problems with r stenosis or um instant thrombosis. Thereafter. Now acute vessel closure was happening around this time in about 2 to 5% of cases. And re stenosis rates averaged about 30% in a year. So it's much higher than what we see nowadays. Um And it sparked a whole um a whole wide range of early research looking into these, these disease processes. Then um after, after balloon angioplasty stents were also developed, the earliest stents you can see here going from top to bottom, you have the giant Turko Ruben stent, the palma shot stent and the wall stent in the US, the uh palma shot stent was approved in 1994 and it was the first one that really gained traction in the United States. Whereas in Europe, the wall stent became more popular. And one important thing regarding these is the, is these actually had to be hand crimped onto a balloon and you had to deliver that along with the guide catheter together over the wire. So the only thing really in the coronary at the time was the wire and you delivered everything over that. So you can imagine these were much prone to stent loss and it was technically very difficult to have a successful procedure in those times. Here's one of the earliest publications looking at Coronary stents and they also published in the new New England Journal and this had 100 and five patients, 23 of which were vein graft interventions. There was complete occlusion in 24% of patients after the intervention and re stenosis occurred in about 13% after an average, about 66 months. And you can see those results mainly on the right here. So initial problems with stents were very apparent at that time and we had some work to do. So what we really need to figure out is what's happening when we balloon or stent a vessel. You know what sort of reaction you could see on the right uh immediately post procedure, you the artery expands and you get good result. Uh but then immediately thereafter you have elastic recoil and the artery wall contracts and then the external elastic membrane shrinks and you have negative remodeling. And then after that, you have a process of neo neo intimal hyperplasia, which is thickening of that intimal layer. Uh on the left, you can also see what kind of inflammatory factors are involved in this uh within the 1st 30 days. And particularly what uh uh research has shown to be very important was uh smooth muscle cell proliferation and a lot of our treatments have been targeted towards that. And we'll, we'll discuss that a little bit further. So, stent thrombosis just a little bit about this. We're gonna be focusing more on things like ISR but um stent thrombosis, uh you can see here, there's several risk factors, procedural clinical um anatomical risk factors, but importantly, absence of A P two Y 12 inhibitor has been one of the, one of the main risk factors. So we really wanna make sure that the, the patients that are getting stents or or balloons have a P two Y 12 inhibitor on at the time of stent implantation. Also, malas position is huge. So if, if you, you can fully expand a stent, but if it's not opposed to the vessel wall, there's a pretty high risk of having stent thrombosis, um late stent thrombosis and that stent thrombosis that occurs over a year out from the intervention. Um Instant re stenosis is a ma major risk factor. But malas position as as discussed is also very important. Now, instant re stenosis far and away. The most important process related to ISR is neo intimal hyperplasia as we discussed. So that intimal layer becoming more thick and thick over time. Um but there are other other risk factors. As you can see uh both procedural and clinical and lesion related. On the right, you can see the classification system for used for ISR that we use in studies on the top. There's focal ISR which can be articulation or gap between stents at the margin or edges of stents or focal within the body of the stent. And then down in the in the lower section is the more diffuse ISR patterns which can be interesting proliferative or even a total inclusion of the stent. So given all of these early stent complications, especially in the bare metal stent era, this sparked a lot of research focusing on what what can we do. And the 1st 1st thought was more drugs, more medications, you know, aspirin, more P two Y 12 inhibitors. They had di uh Diamo dextrin G GP two B three A inhibitors and sparked a lot of research regarding all of this um cipher and tax stents were developed during this time, um which were the initial drug drug eluding stents and they were stainless steel, um had much better designs, but they still had a lot of issues related to these early complications Um And so the first drug coated stent was actually not like the drug coded stents that we use today. It was a Heparin coded stent and it was published in the benet two trial in 1995. Um, they actually had pretty decent results with this. Um They compared des to poba with six month follow up and twelvemonth follow up which you can see on the right patients with the drug alluding stent had much better event free survival than those treated with Poba. And then research came out around that time that smooth muscle cell proliferation was really that main factor involved in the neo intimal hyperplasia. And so that led to the, the drugs that we use today on stents, which is like the paclitaxel um camus and then the, the Lymus analogs as well because they, they work, I I won't go into the detail of the um biochemical pathways, but they work against cell division and basically keeping those smooth muscle cells from pro generating. So we'll talk a little bit about stent characteristics and design. After the early stents, we had those uh the stents that have the antiproliferative agents. Uh You can see on the right here is bare metal stent and the rest of these have antle agents, paclitaxel here, Camus, zotarolimus and everolimus. And basically what this shows is about 30 days out the endothelialization process that happens in the stent wall or, or, or in the vessel wall and how the stent endothelial iss. So you can see actually with the bare metal stent, it happens much faster. You see it's very smooth. Um Whereas with the inter proliferative agents, it doesn't happen quite as quickly and maybe a little bit better with the Ees and the Zes than the others. But that is what led to us requiring these patients to be on longer DAPT uh because it takes longer for those stents to endothelial. OK. Manufacturers, then ha ha also had to look into a lot of different technologies uh in order to elute these drugs fro from the stents. So it, it does take some work to try and get this process happening over the course of months. Um in order to, in order to aid that endothelialization process and decrease inflammation. Um so I won't go through all of these. But the gray part is the polymer coat and the um the black part is really the, is the stent. And so in a, you see that there's diffusion of the drug through the polymer. In B there's an additional polymer coat that the, the drug goes through. And then in C, the polymer actually swells and D there's no polymer and the drug actually gets eluded from the stent itself and e there's a stent reservoir and then there's uh there's also um in five or, or an f there's bios or biodegradable polymer that gets the drug gets released as the polymer degrades and then there's some others. And also I'll just mention J is basically a, a bio resorbable polymeric stent. So the bio resorbable stents here, you see, as stents evolved and continued to advance. Uh the earliest stents are here, taxus and cipher on the left. But then stents became much thinner uh to the point where they're half the thickness of those early stents. And some of these ones that we use, especially the, the thinnest one that we have here is the syo stent, which is only um it's 60 compared to 40. Uh I think it's I'm not sure that the level of measurement, but I think it's like microns. Um and then also the polymers have different levels and variations of thickness. Uh Some of these polymers are also biodegradable, including the synergy stent, which we use. Uh this is bio biodegradable polymer. Another thing that, that evolved during this time was stents were stainless steel and then they became more Cobalt, chromium or platinum chromium. And that's, that's how they were able to make these thinner, thinner strut stents. So despite all these advances, we still have some, we still have some difficulties with, with drug alluding stents. And it's something that we sort of see in practice every day as interventionalist. Um And also, you know, clinicians, anyone working in cardiology, you, you deal with this. But um but uh drug delivery is one of them. So with the stents and the polymers around the um stent struts. You, you really can't cover the entire the entire vessel because it's only covering about 15 to 25% of the vessel. So there are some areas where that drug doesn't get to completely. Um Also we mentioned that the need for longer term DAPT which not everybody can do. Um Also the durability of stents both in small vessels, long lesions uh and considering bifurcation lesions, that's been something that we've seen over the years. Uh these patients are at higher risk for instant re stenosis. And then there's also late and very late stent thrombosis with early stents in the bare metal. And then even um in the early drug eluding stents in the tax cipher areas, uh we saw a decent amount of patients with late and very late stent thrombosis. And so that sparked some research as well. Um And actually, as you can see here, um here's a meta analysis sort of looking at different uh drug alluding stents with different anti prolific antiproliferative agents. And actually this shows that um with the ees, the everolimus saluting stents, Cobalt chromium, in particular, there was less uh less late stent thrombosis in those patients and that there has been other, other large studies that have confirmed this as well. So with stents where we at now, we have come a long way. But despite these advances, we have stent failure and this usually means ISR um target lesion failure rates which includes ISR is about 3 to 5% in the first year. And this is usually what I tell patients before we do an intervention to it. You know, I tell them if they ask me specifically about stents and how long they last. I usually tell them you can expect, uh, uh, 3 to 5% failure rates in the first year. And then about, um, less than, uh, less than 1% or really 0.2% to 0.4% every year after that. Ok. So now moving on to drug coated balloons, uh we'll go in first the properties of drug coded balloons. And what makes those, uh what makes them successful? And then we'll go on to some, some of the data. So drug coded balloons were developed initially in this era of wanting to really leave nothing behind in the arteries uh cause we were seeing, you know, patients coming back with lots of stents, lots of ISR and we really want, wanted to avoid, you know, doing that moving forward. And so there's, there was a focus on leaving nothing behind. Um I remember in my, in my training Interven Interventional fellowship, you know, many of the, many of my mentors had said, you know, you, if you balloon something, you really ought to stent it, but we'll find that that may not actually be the case. Um And there are, there are situations where it's just not practical. So, um what is it a drug code, a balloon. It consists of three things, uh a semi compliant balloon, a polymer matrix coding and also an excipient. So the, the matrix coding actually contains the pro proliferative agent. And then the excipient is basically a medium through which uh the drug gets transferred and it helps facilitate the drug transfer into the vessel wall. As of 2020 there were about uh there were these uh available drug coated balloons on the market far and away more than the others. The sequent pleas is the one that's been the most studied and that's all been European trials or, or also Japanese trials and in another um non US territories. Um The agent is one that we'll discuss a little bit further, but it's, it's also paclitaxel drug coated balloon similar to the sequent pleas. But that's the one that we're studying in the United States and, and should have approval uh by the end of this year. And then there's uh in the claus category or C Lius. Um There's the virtue drug coded balloon, which actually the virtue and the sequent pleas had in 2019 had FDA approval for uh investigational device exemption. But I, I'm not sure exactly what happened, but no research has really been done in the United States on these and I don't know if it was related to COVID or, or exactly what. Um but those have actually not been studied yet in the United states, there may be some ongoing trials but nothing published as of today. So drug coated balloons, they're not, it doesn't sound like it's a super complex thing, but there is a lot that goes into really making, making something that seems so simple work really well. Um So in, in developing drug code of balloons, manufacturers and scientists have to look into a variety of factors which are listed here. Um You need something that has a homogeneity of the distribution of the drug along the surface. It has to be stable during production and delivery. You have to have uh you have to account for the amount of drug that's lost during the delivery. Also, the um the drug has to be delivered during expansion during a very short period. Uh so that you don't have prolonged balloon inflation times. And this is, this is particularly important for coronary compared to peripheral where in peripheral space. When we use drug code balloons, usually people, uh usually operators will leave those up for about three minutes. Um Whereas in the Corinna, that's not something that's really practical. Um Also particulate loss downstream is very important as there's, there's a substantial amount of drug that does get lost into, into, into the downstream circulation. So why is Paclitaxel a good choice? Um Well, it has high lip lipophilic and that makes it ideal for binding to the balloon as well as retention at the site of delivery. And uh and and you could see um addition of contrast was one of the initial things that they studied that showed that improved the solubility and dramatically increased the amount of drug that was delivered to the cell constituents. So um that's what led to the sort of the sequent pleas being developed with a sort of a contrast agent. The I iopromide is what it was called. Um And then since that time, other manufacturers have developed other excipients that are a little more advanced that, that also help with that process. But typically, um somebody asked me before I gave this talk, you know, how much drug is lost during delivery. And you know, when you're trying to get that balloon to the, to the, to the vessel, it's about 10%. So it's really not that much. Um And about 80% of the drug gets released during the expansion, some of which goes into the vessel wall, some of which goes distally. And I think that is partially dependent on what excipient you're using. I don't know the exact numbers for each balloon and I'm not sure the manufacturers would really release that information. Um LIMAs coda balloons have also been studied, but it's a little more complex and it requires delayed release technology because um it, it is a lot harder for the uh Camus or the or Lymus analogs to be retained at the, at the cell level. After many days in the Paclitaxel studies, they've shown that paclitaxel is still present up to 30 days after the, the use of the drug coated balloon. Whereas in the in the camus studies, it's, it's not there at that time and they have to use a delayed release technology. So one of the probable reasons for delay in using drug coated balloons in the corner in the US was this statement that was issued by the FDA in 2019 in regards to the peripheral drug coated balloons, uh where they reviewed some randomized controlled trials. And there was a signal for mortality. Um and this was actually all cause mortality in patients and, and it was late deaths that were seen uh up to five years after the case. And um unfortunately, this was, this was also in the in the setting of seeing that these patients had decreased re stenosis rates and decreased need for revascular revascularization. So really the there there may have been a signal for increased mortality, but it wasn't necessarily related to the results of the drug coated balloon. And so the FDA issued an update to physicians and health care providers actually just last year that said that these paclitaxel balloons are unlikely to increase risk of mortality. And there have been other studies that show that that's the case as well. Uh So what kind of lessons have we also gained from peripheral studies? S fa risk of re stenosis is up to 50% in six months for very long lesions in the setting of stents. And so, um so basically, they, they moved towards more using drug coated balloons for very long and calcified lesions, but they may not be as effective. So oftentimes in these cases, like if it's a very long CTO, you may stent the proximal part of it, but then use a drug coated balloon for the rest of it to try and decrease the amount of stent that you're, that you're using. Um And then also understanding, you know, successful results and acceptable results. So when we use drug coated balloons, you're not necessarily looking for a perfect or near perfect result. Uh like we might get with some of the stents that we use cause you know the stents, you get a, you get a pretty result upfront, but sometimes in certain situations that might mean more problems later because of just leaving the stent there. So let's review some of the data on drug coded balloons and the corries outside of the US. And some of the early studies in the United States. First, we'll talk about instant re stenosis. Um Coronary drug coded balloon has a wide range of possible uses that are listed here. Most um the most important of which is instant re stenosis. And that's what we'll mainly be using it for as it rolls out later this year. But you can also use for small vessels, bifurcation lesions, acute M I and there's, there's studies involving all of these things listed here. One of the first uh paclitaxel drug coded balloon studies in the coronaries was published in 2006. So it's been a while. Um that Europe has been using this. It's been over 15 years and it did show a profound difference in six month angiographic results compared to poba for instance, re instant re stenosis. And this was a small study but still very, very profound results in the initial study, drug coded balloon for ISR, as I mentioned, has been available for over 15 years in Europe and also in Japan. Uh there's been multiple randomized studies investigating drug coded balloon, both for bare metal stent intent, re stenosis and drug alluding stent and sentry stenosis. And this led to the 2014 ESC or European Society guidelines that recommended as a class one level, a recommendation for drug coated balloon for treating ISR. And this, this is pretty important because that did lead to long stream or, or widespread use of drug coated balloons in those other countries. Whereas in the United States, we haven't been using it. Here is the P PC AD two trial which uh we'll, we'll go into some of some of the details of these trials, but not a lot. Uh But this compared Paclitaxel coded balloon to Paclitaxel coded stent. So it was one of the first drug coated balloon versus drug eluding stent trials for instant re stenosis. Um And actually in this trial, drug coated balloon was superior to the drug alluding stent for the treatment of bare metal stent instant re stenosis. And they used the primary outcome here of late lumen loss, which is basically a process of, you know how the lumen that you get after the intervention compared to the lumen that you have when you follow up geographically, how much, how much has it changed? So 0.18 millimeters means um it went 0.18 millimeters down over the course of several months. Then there, there were some more trials looking at um DC B for ISR, we have the ISR Desire three and the ribs four trials on the left and the Ir Desire three trial. Uh It looked at drug coded balloon versus uh paclitaxel eluding stent, the tax Liberte. And this trial showed that drug coded balloon was safe, good uh comparable option uh to, to drug alluding stent for de si sr and there was no need for an additional layer of stent. So they used kind of a softer end point which was diameter stenosis of follow up, which was, which was similar between the groups. Um They also studied Poba in that trial and Poba did not match up to the to the drug alluding stent or the drug coated balloon. Um The Spanish Ribs trial, ribs four trial on the right. Conversely showed that the use of an uh Eola mi saluting stent for de si sr most likely decreases the the need for reintervention compared to the drug coated balloon. And there was a, a mace difference or um or basically major adverse cardiac event difference between the groups, but it was completely accounted for by the, by only the need for rein interventions and not by increased increased death or mortality. Um So there were conflicting results of these two. And here you see this is 10 year data on the Isar Desire three trial, which showed that drug coded balloon and des were comparable and better than P A for ISR. But given these con conflicting results and a little bit mixed results. Uh The, the United States guidelines uh really advised for using a drug looting stent and said that this may increase need for rein interventions and improve outcomes in patients who are appropriate and also could, could do prolonged AAPT. But keep in mind that many of these studies also did not require intravascular imaging. These were done at times where the, the way that we did interventions was different, we didn't use high pressure balloon inflations. Um And I I looked through, I looked through everything and they were using pretty low pressure balloon inflations, they weren't using scoring or cutting balloons either um which may have an impact on, on durability. So what are we doing in the United States for these patients with ISR? If we don't have drug coated balloons? Well, that's shown here. Uh The by far, the majority of patients, more than 70% are getting stents. A second layer of stent. There are about 20% who do not get a second layer of stent. A no stent method which could be just ballooning. Um More that, that's probably what it is. And then there's also bare metal stent that those have gone out of favor over the years. So we're not really using bare metal stents anymore. And then brachytherapy, which has been not widely available. And so it, it doesn't account for the majority of patients who have instant or stenosis. Importantly, um ISR does account for about 10% of all PC is and in this registry of about of over 100 million patients over these years, um that equated to up to over a, over 100,000 of the PC is during that time, in contrast to what we're doing in the United States, you see here, this is from the uh Japanese PC I registry and how they've been u utilizing drug coated balloons over the last 78 years. And you can see that the, the percentage of DC B use over that time has gone up dramatically. And I didn't, I didn't see anything as far as Europe, what percentage it is that they're using drug coded balloons. But I imagine it's, it's similar to what they're seeing in Japan. So now on to um the, this main trial that the first US trial of drug coated balloons. And that's the agent ID E trial. This was presented at least the preliminary data at TCT back in October. And this was similar to some of the earlier trials that were done in Europe in which were comparing drug code, a balloon to balloon, an angioplasty. And uh you can see this was a pros prospective multi center randomized trial, 480 patients, most of which had DC B compared to the PBA. Um You could see the exclusion criteria. This was des or BM SI sr typically shorter lesion lengths. And of note, intravascular imaging was used in 75% of these patients. It was not required to use it but it was encouraged. And so that's a pretty good number compared to some of the older trials that have been that have been published. Um Also of note, multiple layers of stent were present in about 44% of these patients. So, Dafter was required for at least one month. Daft usage was similar between the groups, post procedure measures. And uh procedural success was similar between the groups and on the primary outcome target lesion failure. At one year, there was 17.9% in the DC B group compared to almost 30% in the POBA group. And this was significant for superiority. So clearly drug coated balloon is is um superior to Poba for the use of ISR. OK. And this was pretty dramatic with the number needed to treat less than 10 and equates to a relative risk reduction of about 38%. OK. And there were also importantly, um instant thrombosis, there was no instant thrombosis in any of the DC B patients. Looking at the subgroup analysis, there was um a greater difference in target lesion failure for the multiple layers of stents than for those with a single layer. Um I think you can see that there's a trend towards significance for the single layer of stent. But I think this study was just not powered enough to really detect, to detect that. And I think using DC B for a single layer of stent is still probably better. So what's the take home of this trial? DC B is, is superior to PBA or PTC A for ISR DC B is safe with low risk for instant thrombosis. And DC B is likely a good alternative to drug alluding stents. We can extrapolate that especially in patients with multi stent ISR where you, you really don't want to put another layer of stent. I mean, it's you, you should not put a third layer of stent in, in a coronary for one. So one of the drawbacks of this, the main drawback is probably that it didn't compare against drug alluding stent, which has become the standard for first time ISR in the United States. It also did not require high pressure balloon inflations or scoring balloons and it did not require intravascular imaging. So this is a ISR uh algorithm that I first saw uh in 2020 was when I was doing my interventional fellowship, Doctor Waxman with Washington Hospital Center presented this at the C RT Fellows course. And it sort of helped me to conceptualize, you know, you know, when you have instant re stenosis, why do we do what we do when we, we use laser, when we would we use brachytherapy, all those different kinds of things. Um You know, sometimes we have to rota through a stent that, that kind of thing. Um And this unfortunately did not account for the use of drug coated balloon because it's not something that we were using in the United States. So it actually sort of needs to be updated and there's a lot of situations where drug coated balloon would be of a feasible and reasonable option for patients who have um instant re stenosis notably. However, um drug coded balloon may not be as effective with calcified lesions and in calcified lesions, uh with intent recent notices, you really wanna uh lean more towards using like intravascular lit lithotripsy or, or laser and potentially placement of an of another stent in those situations. So let's go through some cases. Um First one is a 76 year old female with an NSTEMI and cardiomyopathy. She had RC A stents that were placed two years ago. And here's how the RC A looks now um this, in my mind, this is just, I saw this case come up a couple of weeks ago and I, and I saw this and this would be a perfect case for a drug coated balloon because it hasn't been that long since the, um, since the stent was placed. And it's also a relatively focal sec segment of the coronary. And that's the kind of patient that, that would have been approved for a trial like this. Um the left system, there was some disease in the left system as well, but this was clearly the culprit lesion. And I think drug coated balloon would have been an option for this kind of patient. Ok. Um Next case is 81 year old with an NSTEMI and um severe osteo ISR of a vein graft to an OM as well as mid SSVG proximal ISR. These stents were placed over 10 years ago. And while this kind of patient would not be someone that they would have enrolled in a trial because they would typically exclude vein grafts cause vein grafts are at increased risk of, for instance, re stenosis in themselves. Um This is still something where I might consider using a drug coated balloon because in vein grafts, when you have two layers of, of stent, really, the rates of failure are pretty high. And if you can get away with a good result using a drug coated balloon, um I think that might be a reasonable option. Um The issue is you'd have to use two with, with this one, I think the proximal one is instant and the mid one is more um at the edge of the stent. So you might consider just using a, a stent on the distal one on the ibis. You can also see um significant uh fibrocalcific change within the um within the stent as well as within the vessel itself. So we opted to stent both of these considering that we didn't have drug coated balloons available, but end up getting a good results. It's just that the longevity of this is not gonna be that great. Here's another case, a 74 year old with an abnormal stress test and um CCS three angina and a prior PC I of the native circ proximately. And they're known to have an inclusion of a vein graft to a diag but the limb from a dia the diag to the om is open and you're getting retrograde flow and there's a severe distal circ lesion. And so plan to just treat that, but where ISR comes into play and sometimes you don't expect to need to deal with it. But in this particular case, that proximal segment I I'm showing the IVIS here, it had a MS a of 3.5 millimeters squared and there was incomplete expansion which you can see on the lower image or good expansion, but incomplete opposition. And so in order to get even get a, a stint down into that distal segment. We had to, um, we had to balloon within that stinted segment guide liner wouldn't go. The IVIS would pass just barely, but nothing else would go. And so we ended up having to balloon that proximal segment. So a drug coated balloon might have been of good use there to get full expansion of that, that prior stent or at least better longevity after ballooning or at high pressure. Ok. And final results there next, we'll move on to a small vessel. DC B for small vessels. So what constitutes a small vessel? In most trials? The upper limit is gonna be 2.75 millimeters but others consider it to be le anything less than three millimeters. This does represent a significant portion of uh PC is up to 35 to 40%. These patients are at higher risk for re stenosis at about 8% in a year and 10% in two years. And one study did show that target lesion failure for vessels that were 2.0 to 2.5 millimeters was much greater than those that were, that were greater than that. So really the definition take it with a grain of salt, but I think the smaller it gets the higher the risk of of instant re stenosis. There were multiple earlier trials looking at small vessels in DC B, you can see basically the gist of, of what they found. Um, and I won't go into the details, but, um, the table here that's presented fro is from the Bellow trial and they looked at geographic outcomes six months uh after and patients who got DC B compared to those who, um, who had uh balloon only and there was much or I'm sorry, not balloon only DC B compared to um, uh drug alluding stent and there was much less late lumen loss and those who had the balloon. So if you don't leave a stent there and you get good results on a balloon, the chances of having late loom and loss or instant re stenosis basically is much lower in those patients. Some of the more recent trials looking at DC B for small vessels, there's the basket small two trial and the Picolet two and these were done around the same time in Europe. Um Both multi center randomized control trials looking at uh DC B versus des, the basket small two trial showed that DC B was non inferior to des and small vessels. And the picolet two trial showed the DC B may be better than DES for small vessel disease due to the decreased late loom and loss in these patients. So pretty good results for small vessels. Here's a case uh where there's a patient who has a Lima that's patent. But then distally just beyond that, Lima, there's a sub total occlusion of the L AD and came in with an N sty and a drop in the ef down to 35%. So I included this one in the small vessel because it's actually, it's not the biggest L ad distally and it ended up being like a 2.5 millimeter stint. And due to the proximity of the anastomosis for this patient, um I think DC B might have been a good option because historically, we would recommend only Poba for treating the anastomosis. And, and that was really the common practice up probably until just a few years ago where stenting has now been more common at the anastomosis site of the Lima. However, the there is increased risk for instant re stenosis if you do stent at the, at the site of that anastomosis. So DC B might be an option here. It's not something that's really been studied. Next, we'll go into a little more detail on bifurcation lesions, the others we won't go into as much detail about both due to time and um because there hasn't been much data on it, but bifurcation lesions are also really important in an area of interest for drug coated balloons. Uh It represents about 15 20% of PC is there's a high degree of procedure of failure complications and decreased outcomes. Um This is just a representation of the areas of, of sheer stress where stenosis are common to develop around these areas of low sheer stress initially. But then after you stent re stenosis occurs more at this area of high sheer stress. There's a lot of different algorithms that have been presented about drug coded or about um a bifurcation stenting. And really one of the, one of the things that stuck with me in my training was uh one of my mentors told me the best two strength two stent strategy for a bifurcation lesion is a one stent strategy. So really if you can fix it and have good results with one stent, that's better and typically has better outcomes. Um There are situations where you would need to do a two stre two stent strategy. But I think more often than not, we try not to leave as much metal back as much metal there because there's gonna be overlap segments as well. There's a lot of DC B bifurcation trials that have been done. We'll just talk about one of them briefly here on the left. You see the results from the DC B bifurcation trial. It shows uh what they studied in this is basically um you know, either either using a DC B for the side branch versus using a um just a balloon. And there was, there was much better results with using the DC B compared to the balloon, both in um minimal Luminal diameter of the side branch right here and also in late LU and loss of the side branch. So the, the Deb group had much less late looming loss on the right. You see the hyper trial, which uh was a substudy that was done on the patients who had bifurcation lesions. And these lesions were treated not in a randomized fashion compared to anything else, but just to show that this was feasible and safe. Um But the bifurcation lesions, the main vessel was stinted and then the side branch was uh ballooned with a drug coated balloon. And um there were no cases of bailout stenting in this. There was one patient who had peri procedure M I but overall the results were really good and showed that this was a safe practice. I'll show a couple of cases of uh bifurcation cases. First one is a young patient 34 with an Nstemi and a circ bifurcation lesion. You can see there involving 20 MS cannot. And unfortunately, the smaller OM is the one that has the most disease, but it looks like both of them need to be treated. And I think using a drug coated balloon on that smaller one might have been reasonable because for one, it's a smaller vessel about 2.0 to 2.25 millimeters. And um a two step method is probably not preferable if you have something that, that's that small. Um We ended up having to stent both, but I think drug coated balloon might have been the, the first option if we had drug coated balloons available for this indication. Next we have a 63 year old with an N semi and a new low ef in that first image, you can see there's left main disease. There's also a culprit circ lesion and the proximal circuit itself has less than 50% stenosis. So, um I initially went with a provisional strategy for this and used kissing balloons at the end after stinting the main vessel and we got good results. But I think still optimal strategy for this, if we had drug coated balloons available, might be using a drug coated balloon on that side branch rather than ballooning because there is going to be a little bit increased risk of re stenosis if you just balloon the territory and don't stem it or don't use a drug coated balloon. Ok. So QM I, there is one study that was published during my fellowship. Um I remember when this came out, I thought it was kind of interesting but um using drug coated balloons for a QM, I is something, you know, where we've gone away from using balloons for a QDM. I for such a long time. I was, I just thought it was very interesting that um they were even doing studies on this. Um And they did find that using drug code, a balloon uh was safe and these patients did pretty well. The endpoint was FFR value at nine months which was comparable to patients who had drug alluding stents. Um bailout stenting was needed in a significant number of patients due to mainly dissections. Ok. And so there's still a lot of studies that need to be done regarding drug coated balloons. But um overall, I think we do need to prepare to uh use these and be prepared to also treat these patients after after the ballooning process. Um particularly for ISR we need to be familiar with these techniques. Lesions really should be predilated with scoring and cutting balloons. First. This has been shown in trials that you get better results both angiographically and clinically. If if patients are are treated with high pressure or scoring balloons, anybody with ISR also, you should be using intravascular imaging 100% of the time. Um unless the IVIS can't go or um or the oct um for de novo small vessel lesions, we should be pre dilating with a balloon vessel ratio of 0.8 to 1.0 to avoid significant dissections and consider scoring balloons in these patients. Also, if calcification is present, looking at the different types of dissections, we also need to be more comfortable with having an acceptable result versus a perfect result. I think with stenting, we've been pushing more towards like more perfect results as much as we can. But with drug code of balloons, these results aren't gonna look like stent results and what an acceptable result is defined as is less than 30% residual stenosis, no type C or worse dissections and Timmy three flow. Ok. So that's what we would need to be looking for with these interventions. And anything, anything that meets that criteria, it's acceptable, leave it alone and these pat these patients actually do. Well, what's the D A strategy gonna be when we use drug code of balloons? What's recommended right now is three months. But if people have bleeding complications, there's not going to be any problem stopping this one month after a as you know, we we often have trouble with or sometimes we'll have trouble with, with stents. Um We also need to in individualize these approaches. So if somebody has many layers of stents or multiple ISR, you might keep them on dap for longer. Um Patients at high bleeding risk, you might leave them on DAP for L for a lesser time. Ok. So that concludes the talk um in, in order to summarize stents have come a long way, but we're still having issues with ISR or um late stent thrombosis. In most de novo cases, current generation des is still preferable D CBS have a wide range of uh potential clinical uses. Most promising. So far instant re stenosis, small vessel disease and potentially bifurcation lesions. As we discussed, DC B is coming to the United States, which will likely be by the end of the year and will this will likely have a lasting effect on PC I strategy? Probably increasing our, our rates of use up to 15 20% as has been seen in other countries. And operators need to be familiar with best practices if choosing a DC B strategy, consider also individualizing this and patient characteristics. Uh in order to account for when choosing A DC B or DS strategy. There's my references and thank you the chatbox. The first comes from Doctor Battier and his question to you, Justin is do drug coated balloons reduce the duration of depth? And what is the rate of uh dissection crossing over to the stent? Uh DC B? Um definitely does reduce the duration of debt compared to drug alluding stent. Um The, yeah, the current recommendation as I mentioned is three months after, after the uh placement of the drug code a balloon. But this, I would imagine that this is just kind of a conservative strategy right now because it's new. I think that it probably would be decreased down to about one month. Um, Published March 6, 2024 Created by Related Presenters Justin Heizer, M.D. Sentara Cardiology Specialists View full profile
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