SPEAKER: OK, hello, everyone. Welcome to Medical Grand Rounds. Thank you for those who are tuning in via Zoom and those who are here in person. Today, we are pleased to have Dr. Ken Bilchick here to discuss MRI imaging in patients with implantable pacemakers and defibrillators. 

Dr. Bilchick completed his bachelor's at Dartmouth College. He then traveled South to Johns Hopkins where he completed his medical school training, internal medicine, cardiology fellowship, and advanced fellowship in clinical cardiac electrophysiology. We were fortunate enough to recruit him down to UVA in 2007, and he has quickly made his mark. 

I've had the pleasure of working with Dr. Bilchick as a resident here. And what has struck me about him is his ability to wear so many hats and multitask. He's a fantastic educator who has given multiple talks and conferences to fellows, presidents, and medical students. He has a bustling EP practice, and has become the director of the advanced imaging and cardiac EP and heart failure program. 

In 2010, he completed a masters of science in clinical investigation and was bitten by the research bug. And his academic career has taken off. Currently, his research interests are at the junction of advanced cardiac imaging, cardiac devices, and heart failure. He has published numerous peer-reviewed articles and is presenting at every national cardiology conference. 

He took on the role as director of research in January of 2019, and if that's not enough, he's currently enrolled in a master's program in biostatistics. Dr. Bilchick, we are thrilled that you have made time to give Medical Grand Rounds. And it's on such an important topic that many of us are curious about. And with that, here is Dr. Ken Bilchick. 

KEN BILCHICK: Thank you. Thanks. Thanks for the wonderful introduction. So we'll be talking about MRI and patients with pacemakers and ICDs today. This is an area, I think, that impacts us all. You have patients that you'll be sending for various diagnostic studies and many of them will have devices. 

So I'd like to outline the learning objectives. We want to identify the benefits and risks of MRI scans in patients with these devices. We want to be able to distinguish between MR conditional and non-MR conditional devices. We want to describe the impact of abandoned leads on scanning a patient and talk about what abandoned leads are. 

And we want to describe the precautions and monitoring protocols recommended for scanning patients with devices. And then we want to talk about one example of how CMR can guide management in patients with devices. 

And so we'll go through these Frequently Asked Questions. I grew up with David Letterman and everyone likes a top 10 list, right, so throughout the talk I'll be addressing these 10 questions in appropriate places. And so you can think about really practical things that might come up in your practice and might help you. 

So we'll focus first on First Learning Objective, which is to identify the benefits and risks of MRI scans in patients with cardiac implantable electronic devices. So CIED is cardiac implantable electronic devices. It's the general term that we use to describe these heart rhythm devices, including pacemakers and defibrillators. 

So MRI is a powerful diagnostic tool. And it's based on non-ionizing radiation. We get excellent differentiation of soft tissues without the need for iodinated contrast, and it's now really the gold standard for a number of diagnoses. In the figure here, you can see the difference in a spinal imaging for a CT and MRI where the T1 hyperdensity is identified very nicely on the MRI better than the CT. 

And MRI access is a growing need. You may have thought about how many of your patients may have these devices, and how many of those that have these devices will eventually need an MRI scan. The numbers are pretty big. So 2.9 million patients received pacemakers in the US between 1993 and 2009. 

And it's actually estimated that about three out of four patients with pacemakers will need an MRI over the course of the lifetime of the device. And in addition, patients with ICDs are growing as we have increasing primary prevention indications for ICDs. And there's an increasing need for MRI'S in those patients as well. 

So I just wanted to go back and talk about the history a little bit, right. We need to-- this is a rapidly developing field with MRI, and I think you should appreciate the history here, where we've come from and where we are now. And so the first pacemaker you may know was back in 1958. 

The ICD was developed in Baltimore by Michel Mirowski. There's a great story about his life and how he developed this device that has now become so commonplace. You can see the difference in size in the device from 1980 versus 2009. So the devices have gotten a lot smaller. Levi Watkins, who passed away recently, was a groundbreaking surgeon at Johns Hopkins, and he actually implanted the first ICD in 1980. 

So here's a brief history, maybe not of all time, but of at least MRI pacemakers and ICDs, so here you have it. So the first pacemaker was implanted in 1958. The first ICD was implanted around 1980. And then in the 1980s, we saw the increasing use of MRI for clinical diagnosis. 

There are early studies demonstrating safety of MRI with pacemakers. And this was a big deal, because for a long time it was absolutely thought to be taboo to put a patient with a pacemaker in an MRI scanner. for the concern of magnetic interactions with a metallic device. It turns out, though, that pacemaker circuitry and leads have changed over the years, and now we have accumulated, particularly with newer devices, a pretty good safety data for these devices. 

This led to this push for FDA labeling for an MR conditional device. And now we don't call it MR compatible, we call it MR conditional, because the ability to perform the scan in a patient when the device is labeled conditional on certain practices. Like, you have to reprogram it a certain way. There has to be certain monitoring and things like that. So we call them conditional devices. 

And so we had the first MR-conditional pacemaker the Revo, in around 2011. It was approved by the FDA. And then, over the period from 2015 to 2018, we had the development of MR-conditional ICDs with FDA approval. And in 2018, CMS thankfully agreed to cover scans even in patients with non-MR conditional devices. And this was a holdup in doing more routine MRI scans in patients with these devices. The payment was certainly an issue. 

At UVA, we have a program that's been in existence now for about 10 years that we started back in 2010 when I was junior faculty here working with Jamie Weathersbee, chief MRI technologist at the time. And it's really grown as I'll show you on the growth side coming up later on. 

And somewhere around 2016, to accommodate this increased growth, we created this MRI cardiac device coordination system which is designed to facilitate multidisciplinary review and safety for patients getting these scans. And I'll explain some more details about that. 

So we want to talk about the risks of MRI in patients with these devices. MRI we think of as having three fields, a static, a field a gradient field, and an RF field. And these have different effects potentially on the device. So the static field can exert force torque, force and torque which are essentially closely related, vibration and device interactions. The gradient field is associated with case heating and vibration stimulation, device interactions. And radio frequency field, you can see the effects of that as well. 

So I'd like to give you a trip down memory lane to high school physics taking your electrical and magnetic subsection courses. And so you may remember that there's this thing called electromagnetic induction, right. And so this was an experiment done by Faraday a long time ago. And the idea was you had a magnet, and you had a coil wire, and there was a galvanometer hooked up to the coil wire. 

And so, essentially, you started out by having the magnet stationary, and then you started moving the magnet away from the coil, and it would be some deflection in the needle in the opposite direction. And then when you move the magnet toward the coil then the direction would be the other way. And then [INAUDIBLE], the dial would read zero when the magnet wasn't moving again. 

And so what was going on here is that you're inducing an electrical current in the wire by a changing magnetic field. So that 5B is the magnetic flux, and that's the derivative. And so the change, what's this is saying is that the electromagnetic field or electrical current in a wire can be induced by a changing magnetic field. Well, we do that with an MRI, right. With an MRI, we have changing magnetic fields to image tissue. 

So the leads are metallic devices, and it can concentrate and amplify local energy. And so there are certain categories of leads that are important. They're fractured leads, and epicardial leads that are a particular consideration. So the fracture leads are more dangerous, because in that situation you actually have a disconnect between the wire, and you have an unstable electrical loop that's not complete-- it's not complete. 

And then in the case of the epicardial wires. There's no blood flow, right, so the concern about epicardial wires is, we'll show an example later on, is that as opposed to endocardial wires where you have blood flowing around in the lead to cool the lead, you don't have that with epicardial leads. 

So there are these three categories of leads that have been of particular concern with MRI. One is the fractured ones, the epicardial ones. And then we'll talk about the abandoned ones as well. 

So first question here. What is MI, and why is it important when scanning with devices? So MI is electromagnetic interference. And you may know that the way a defibrillator, for example, works-- the way a defibrillator works to get the signals to determine if you're having ventricular fibrillation is it looks at discrete deflections. And you can see here that the electromagnetic interference can mimic the ventricular fibrillation signal that the device might see from the heart. 

And so in this case, then, you can see these markers on the bottom that say VF, and so you wouldn't want to have this situation in the scanner, right? Nothing uglier than a patient getting shocked in the scanner, so that's not good. So this thankfully can be avoided with programming in the sense that what we do is when we have patients with defibrillators in the scanner we turn off the tachytherapy, right. So that it's not detecting-- it's not looking to detect any VT or VF. 

So here's an example in synchronous mode for a pacemaker. The gradient field can mimic intrinsic cardiac electrical activity. And so you see here an example where you have this noise in the middle of the tracing, and there are no real QRS complexes. The device thinks there are. It thinks there is a cardiac signal, but there are no cardiac signals there. And as a result, you have a pause. 

And if someone's dependent and pacing, and they have a long pause in the scanner, that's not good. Once again, though, this can be easily addressed by programming the asynchronous mode, asynchronous mode, meaning that your programming that the pacemaker to pace, but not since. So it's ignoring any-- it's not looking for anything. It just pacing. And so that's how we do it. OK. 

So frequently asked question number two what is a power on Reset? So power on Reset, it's electrical Reset that's designed to minimize the device function when battery voltage drops from AMI or battery depletion. And it can be caused by a strong magnetic field. 

And so the reason this matters is that patients with battery depleted ICDs or patients with older ICD devices are more likely to get this function called a power on Reset. And the impact of the patient in the scanner, to the patient the scanner, is that, essentially, it can limit the appropriate pacing or put the pacing into a mode that we don't want it to be in, and so the hemodynamics could not be good. 

So then the related question is, well, related to this is can my patient have an MRI scan if the device is approaching elective replacement index because of battery depletion. And once again, in these patients we're concerned about, these kind of phenomena like power-on Resets. 

So ERI, it's a good acronym to be familiar with. It stands for elective replacement indicator index. And it means that the battery life of the device is such that this is a good time to change the generator, give the patient a new one. 

End of life, EOL, means that now you've ignored ERI, you haven't changed the device or the patient's loss to follow up, for whatever reason, and now we're limiting device functionality. So if you have a patient, and their device is approaching ERI, the magnetic field from the pacemaker can sometimes just cause a notch down in the battery longevity and push the patient over. 

Sometimes ERI or the patients with battery depletion as you'll see in some of the studies are more likely to have these reset phenomenon. And so the best strategy in this situation is to schedule a generator change first, and then do the MRI. 

So learning objective 2, what is the difference between MR, conditional, and non-MRI conditional devices? So way back, which I would say before 2002, these devices were really concerning. These devices would really behave badly, let's say, in an MR scanner, and even potentially if the battery were not depleted. And so one distinction is between the pacemakers that were before 2002 and after 2002. 

But as you know, even the battery life of the best pacemakers and defibrillators is going to be around 13 years right now. So you can imagine they weren't that good back then, and there are very few devices from before this time now in practice. Ten years ago, that wasn't the case, but now as time goes on, these devices are less common. 

However, the patients still have the leads. What's happened is they've gotten generator changes. So they don't have the devices anymore, but they still have those leads. So the patients are still there with non-MR conditional devices. So we can think of three different categories. We can think of what we call legacy devices. Legacy potentially means non-MR conditional devices. so it's just an easier way to say it. 

So legacy devices before 2002, which are exceedingly rare, and then just legacy devices in general. And then, MR conditional devices, OK. And so some of these early studies-- this was done by [INAUDIBLE], who was a colleague of mine at Hopkins back in the early 2000s, and what he did, this was really an important study in animals and pigs. Implanted these devices and then did MRI scans after they were in for a while, and then looked at tissue histology, because what we wanted to know is how was MRI affecting the tissue? Was it causing fibrosis, tissue injury, and things like that. 

You can see what they found is sort of a casing a little bit around the lead, but it wasn't really affecting the tissue so much. So there wasn't really a difference with MRI or not MRI. And a related question is about torque, right. So do you need to worry about MRI exerting significant torque on a pacemaker or ICD? 

And so if you can imagine your patients in the MRI scanner, is the MRI scanner-- so is the device going to fly out of their chest? Well, it's not. And he looked at this in the study as well. So that the measure force and torque were small and for reference 100 grams is near the limit of what you can sense. And so you can see that the force and the torque are all very small. And actually even smaller for the newer devices, which are shown on the bottom rows. 

So in the interest of making these devices more, say, compatible with MRI, design solutions were proposed. So change the ferromagnetic, minimize ferromagnetic content, isolate the circuit board, change the sensor, optimize input circuitry, circuit component change, things like that. And these developments led to the release of the first MR conditional pacemaker, the Revo pacemaker. 

You probably heard of this. They're made by Medtronic. There was a press release in 2011 and that started the whole MR conditional wave. And what they did with this device-- remember, it's not just the device. It's the leads, right, and the leads maybe are more important than the device. 

So there's an inner conductor coil to mitigate heating and they change the structure of the coil. So there's a study that led to the approval. It was a prospective randomized study where they randomized patients who got the device to get an MRI scan or not get an MRI scan, and then they checked device parameters after they got the MRI scan to see if they were actually different in patients who got the device or didn't get the device-- I'm sorry, who got the scan or didn't get a scan. 

And it passed all the effectiveness endpoint-- atrial pacing capture thresholds, ventricular pacing thresholds, sensing amplitudes, ventricular sensing amplitudes, all these were similar in patients with the device who got an MRI scan or who didn't get an MRI scan. So that was the way they chose to test this. 

Now it's interesting, what the device companies have done since then, is they really reverted to modeling because it's difficult to test a lot of patients just to get an FDA approval. And the FDA is now more amenable to this modeling approach where you-- simulation approach, so to speak, to demonstrate lead performance. 

So here's a question that always comes up or comes up a lot. If the pacemaker or ICD is labeled as MR conditional, do we know for sure that the system is MR conditional? And so here's the thing, right? You can put in MR conditional device in someone with non-MR conditional leads, and it doesn't count. You can make yourself feel better that the patient has an MR conditional device, but the system is not MR conditional unless the specific combination of leads and device are all MR conditional. 

So even if you have MR conditional leads from Boston Scientific, and you have an MR conditional pacemaker from Medtronic, the system is not considered MR conditional. Kind of funny, but it's because the way the FDA labels these is based on the configuration. It's the combination of this pacemaker defibrillator with these leads. So there are very, very specific things that are required for a MR conditional system. So MR conditional system, MR conditional device, two different things. 

Why do some people put in a MR conditional device when the leads may or may not be MR conditional? Well, early on some people were doing it because they thought, well, maybe it's just a matter of time before the leads get approved. The company will do some studies, they'll get the lead improved and it will be MR conditional. 

But in reality, it causes confusion and that's one reason why this device review system has become increasingly useful, because you can't just look at the model number of the pacemaker and say that it's conditional, because you have to look at the leads. You have to look at whether there are abandoned leads and fractured epicardial leads. All these things are important. 

So how do you figure out if your patient has a MR conditional system? Well, it turns out Abbott, which used to be St. Jude, Medtronic Boston Scientific, and Biotronics, they all have websites. You can type in-- you have to do a little work, right. You have to type in the model number of the device. You have to type in the model number of the leads, and determine then, if it's MR conditional. And the device will spit out an answer. 

Now, one thing you may not know is you may look at the device report in EPIC, and it may tell you, you may find model numbers, but maybe there's an abandoned lead. And we'll talk about that shortly. But you could have, once again, a MR conditional system based on the lead and the device model numbers, and it's not conditional because they have an abandoned lead. So it's a little tricky. 

Now one thing that comes up is in the current era what is the advantage of MR conditional system over a non MR conditional system. We looked at this in 100 patients and submitted an abstract to heart rhythm a few years ago. And what we found is that there was very little difference in the change in pacing thresholds in patients that had MR conditional systems or non MR conditional systems. 

So you may be scratching your head at this point and thinking all right, so why the MR conditional systems if you can potentially do a scan safely in a patient with a non MR conditional system? And the issue, really, and that's the next question here, the issue really is that there's less room for operator error because there's batch programming, and it's FDA approved, and it makes everybody feel good. 

But really, from the rubber hitting the road kind of standpoint the batch programming is nice. In other words, before you go an MR scanner, right, you have to reprogram the device. You may need to change the pacing mode to asynchronous. You may need to turn off alerts, you may need to turn off tachytherapy, various things. 

And if you don't have an MR conditional device, for example, then you have to go and change all those things individually. And maybe you missed something. Maybe you screw up, right? The reason the FDA likes these MR conditional systems is that you press a button, you say, I'm ready to go, do the MRI scan, and everything then is just programmed batched. 

The patient goes in the scanner, they come out, and then you go back to the programmer, and you say I'm done with the scan. And it reverts back to the previous program. So there's a big study in the New England Journal of Medicine in December 2017, [INAUDIBLE], just to put this in reference, he and I were Fellows at Hopkins the same year, so he's been very successful. 

And he had this nice New England Journal study where they looked at over 2,000 MRI exams in 1,500 patients with legacy devices to determine the safety of legacy devices. And the results were good. They changed the pacing modes, they assessed outcomes, and there were no long term problems noted. 

96% of the MRI'S were performed without the occurrence of any changes in lead parameters as consistent with our data at UVA. And in a long term follow up, just 3% or 4% of people had some remarkable changes in device parameters, like the sensing or the threshold, usually not that significant. 

And once again, this is hard to assess. We're not randomized, and you don't know would this have happened anyway, because lead thresholds, they change over time. And so anyway, this was really reassuring. 

They did find power on resets, and there were nine events. These are some older devices, the nine events in patients with battery nearing end of life. And in these situations, patients were removed from the scanner, and there were no adverse clinical events. 

So if you talk to Henry Halperin who's the senior guy on this study at Hopkins, electrophysiologist and also MRI physicist, they'll tell you who do you have to be most careful about not scanning with legacy devices? It's the people with battery depletion, right. He's less worried about the people with abandoned leads than the battery depletion people. And so here you see that there were no long term events. 

There was a companion study. This was published, I think, in the same issue from the MagnaSafe Registry with Robert Rousseau. And similar findings that there were no in 1,500 cases, including ICDs and pacemakers, there were no deaths, lead failures, loss of capture, and everything looked good. There were some partial electrical resets, some arrhythmias, and even repeat MRIs were not associated with any problems. OK. 

So learning objective 3, so now let's just talk about the abandoned lead. So specifically, let's define what an abandoned lead is. We hear this, and you just need to know what it is. So what an abandoned lead is, it's a lead that's not hooked up to the device, OK? 

So here you can see, I circled it for you, there are two leads in the right ventricle. Why would you put two leads in the right ventricle? Probably because-- usually there are two reasons. One is you either have a lead where the functionality is not good and you need to put another one in, and you decide not to extract it, because maybe it's old and you're worried about the risk of extraction. 

The other reason would be that you're upgrading from a pacemaker to a defibrillator, and you don't want to take it out. So people have abandoned leads. And so what happens to the one that's not hooked up to the device? We put a little covering over it, like a plastic covering over it, and tie an O-silk around it just to make sure the metal tip is not exposed, and then we just bury it in the pocket, and it's not hooked up to anything. 

So it doesn't really cause a patient any difficulty, but people were concerned about it because why? Because it's an incomplete circuit, right. And then we talked about electromagnetic induction and potential currents, and so they were concerned that you could get tissue heating, dangerous things to the patient because you have an unstable wire there that's not a completed circuit. 

And so interestingly, though, that's becoming less and less of a thing. Here's another example where you see that their wires on the right side not hooked to a device, and wires on the left side hooked up to the device. There are increasing safety data. So this was a Mayo Clinic study. 97 MRI scans in patients with abandoned leads, and there was no evidence of clinical or electrical problems. 

And they even took troponins before and afterwards. They were interested in is their lead heating at the tip that would have caused cardiac injury? And so they measured troponins before and afterwards. Everyone's, like, interested in troponins now, right? From everything from COVID to this. 

But here's another application of troponins. They measured them before and after the scan, and there was no difference. So the bottom line is, we have accumulating safety data, not a lot, yet, but accumulating safety data that looks like probably scanning patients with abandoned leads is going to be OK. 

But it's still not included in the present guidelines, and so what we do is we have a discussion with the patient. If your patient, you send us a patient that has abandoned leads, we'll say, all right, you just need to let the patient know that this is not currently included in guideline expert consensus-based recommendations. 

But there's accumulating safety data. And if they're willing to accept some possible minor increased risk, right, then it's fine, we'll do it. But because it's not currently included in the consensus recommendations that we'll talk about in a few, then we feel we have to have that discussion with the patient. 

All right, so I want to just talk about what we've done here at UVA over the past 10 years. So as I mentioned, that we started this program for MRIs and devices in 2010, Jamie Weathersbee and I along with Dr. Kramer, and [INAUDIBLE], and others. 

And it was a great example of collaboration among departments. And back then, this was really less familiar territory. And so you can see, back in 2010, we're only having like 10-20 patients. And you can see that in-- we scanned 178 patients, even with COVID, we scanned 178 patients so far and 2020 with devices. So we're on target to have about 200 scans. And you can see it's looking a little exponential, isn't it? 

So there's been an increased demand for this, and I mentioned the MRI CDCS to the cardiac device coordination system. This is something that Jamie and I created several years ago, because there's only so much you want to do by email. And it was starting to get messy. And so we contracted with some web developers, and we created this system. 

Now, why do we need to have it? Well, it facilitates a multidisciplinary review by radiology faculty, cardiology faculty, and device nurses to promote safety. And I've already explained to you how complicated these assessments are about looking at lead models, device models, banded leads, various things. 

And then we actually determine the appropriate personnel who need to be present for the scans. And also show you, for some scans we recommend a device nurse be present the whole time, and in other scans a radiology nurse. And then it helps connect everybody and talk about things. It helps connect patients, too, if they have questions, and they can ask questions. 

And then finally, we need a strategy for the programming configuration. Are you going to program to asynchronous or not? The electrophysiologist, electrophysiology faculty, we're doing procedures and various things. And the aim was to empower the device nurses to allow them to know what was going on ahead of time, have some input in the whole process, and then have a plan for programming. 

So these protocols are on the radiology internet and can be accessed. They're formal protocols that we have. Then we have an expert consensus document, and here's a summary of the monitoring of protocols. That's other learning objectives here. So it's a personnel with the skill to perform advanced cardiac life support, a CPR should be in attendance for the scan. 

The ECG and pulse oximetry should be continued for the scan, and personnel with the skill to program the device should be available as defined by your protocol. This comes up, so these are more conditional devices. So typically, the manufacturers will recommend six weeks from the time of implant until the time you do the MRI scan. And sometimes you want the MRI scan sooner than that. And so this addresses this issue. 

As I said, for MR conditional devices, it's OK. It's OK to do the scan. It's OK to do the scan sooner than six weeks. So if they really need it, that's OK. And then for non conditional devices, they say it's reasonable for patients to have scans if they don't have fractured epicardio or abandoned leads. 

Julie [INAUDIBLE] who wrote these, the statement was very clever. This is something worth noting when you're thinking about how you want to write a guideline document. So you see what they wrote. They wrote that there's indication to do it if you don't have these things. But this is not equivalent to a Class 3 recommendation saying that you're committing malpractice if you do. 

So they purposely did that to give people flexibility. They wanted to give an indication in the case you don't have them, but they realized that we wanted to accumulate safety data with particularly abandoned leads. And so they wanted to not give an indication but allow people to do research studies like the Mayo Clinic study I showed you. So that's how they dealt with it. 

And then, these are the ones where we take a few more precautions. So the patient dependent non conditional patients. So the document recommends that personnel with the skill to program the device be present for throughout the scan. So that the two candidate people are the radiology nurses and the device nurses. 

And our device nurses are doing a lot of things, of course, but this is one case where, because the device nurses are the ones that have the expertise in reprogramming, we want them there, not just the beginning and the end, but throughout the whole scan. 

So here's a summary of the protocols if you're not dependent and you have an MR conditional device, radiology nurse monitors, device nurse reprograms. And the same thing if you're not dependent and you have a non MR conditional device. 

And the same thing if you have an MR conditional device and you're a dependent. It's only this sort of bottom right corner where you have non MR conditional devices and you're dependent where we have the device nurse there the whole time. So another purpose of having the multidisciplinary review. 

I showed you the growth over the past year on targets that do 200 scans. And one thing we've struggled with is accommodating the demand. And particularly with COVID, there were some issues with staffing. And also, just in general, with cardiac scans. There's also a wait for four CMRs in general, too. 

And a lot of it is because we do these on the 1.5 Tesla scanner. I don't know how many have been down to the MRI suite, but it's where interventional radiology used to be. There are three scanners there. There's the Prisma of the Skyra there. There are two 3T Siemens scanners, and there's 1.5 Tesla scanner called the Aera. 

And we use the Aera for cardiac scans, for device scans, and for pediatric scans. And so there's a lot of traffic on that one. And our radiology and device nurses, they're salaried staff with prespecified work hours employed by the Medical Center, so they're not here after hours. 

So here, you're competing for this time for those three indications on the one scanner between 8 o'clock and 4:30 or whatever it is. And then you have to staff it, right. To staff it, you have to get scanner time. 

So the good news is Dr. Matsumoto has arranged for us to get a new scanner that we'll have on loan that's going to be in the trailer in the back of the hospital. And we're aiming to-- that was for you, Ben. We're aiming to do dedicated scans, cardiac scans, and device scans on this scanner. 

And we anticipate that once the scanner's up and running, this will really increase the accessibility and allow us to do these scans very, very promptly. All right, so Dr. Ruth is in the room. And Dr. Ruth, you've got to be the DOM hero of the week, I think. I'll have to talk to Mitch Rosner and just put in a plug for you. 

But Kyle Enfield had a patient in the NICU, in the neurology consultants-- not the NICU, the COVID unit for south, and the neurology consultants recommended that he get a brain MRI for change in mental status after having a CT that wasn't revealing. 

And so what does it take to do a COVID scan, an MRI scan in a patient with COVID? You have to essentially clear out that whole three-scan area for at least two or three hours. Because you don't want to have other patients getting MRI scans at the same time. And at the same time, though, we have to do them in the evening, because we have regularly scheduled stuff during the daytime. 

The ED sends a lot of MRI cases, and so even in the evening, this is a cramp. This makes things difficult for the MRI department because essentially then, they can't do any other scans. The three scanners are-- they can only do one scan in the course of three hours or so when they have this. But it's important. We need to do this. 

Now other centers, there's at least one center that Dr. Enfield told me about that actually put an MRI scanner in their COVID unit. Interesting idea, but for now, we really wanted to get the scan done. We thought this was the right thing to do for patient care. 

And so Dr. Ruth graciously agreed to help us out with the monitoring and it was done between the hours of 5 and 7 last night. That's our first-- well, there have been some other MRI scans in patients in the COVID unit. This is the first one that had a device, and they had a monitoring protocol. 

The really cool thing about it was Medtronic now has this iPad thing, and it's wireless. So what we were able to do is before the scan, they brought this iPad thing outside the patient's room. And my understanding is what they did is they took the wand which is wireless with the iPad, had the nurse go in, put it on the patient. Reprogram from outside the room, and then brought the patient down, and then did the same thing when they got back So just creative thinking, all right. 

So I have just final five minutes before we break for questions. I just wanted to talk a little bit more about sort of cutting edge research that we've been doing, and how we can use a CMR to improve outcomes in patients with devices and guide clinical management. 

So we can talk for about five minutes on some of these applications regarding cardiac re-syncronization therapy. So what cardiac or synchronization therapy is, really important device for heart failure. You can see it here. 

There's a device that's in the chest. This has three leads that are connected to the heart. It's designed to correct this is electrical abnormality you see on the bottom there where you have, with blue being contraction and yellow being a stretch, you have simultaneous contraction and stretch at the same time, which makes the heart less efficient. 

And so we've had a lot of success in using CMR to show how we can make outcomes better. Since the response rates in these patients, just without doing it blindly and without any additional imaging information, has been in non-selective populations in the range of 50% to 60%. 

And we actually have a clinical trial right now, an NIH funded clinical trial with MRI guided CRT. And the results so far in over 40 patients look really good. We have very promising post implant findings, more QRS shortening, and longer and more favorable electrical measurements at the lead relative to the QRS complex. And we're continuing to enroll with the primary endpoint analysis plan after we get to that 80 patients. 

We also can use the MRI information in these patients and integrate it with fluoroscopy. So when we're doing an implant procedure, we can convert the MRI information to something called VTK format, which is a pixel-based format, where you can encode information. 

And then you can put it into this program that's integrated with the fluoroscopy. We're the first center in the country to get this, and we've had a lot of great experience with it. And as you can see here, you can see the leads. And then you can see the overlay of the MRI that on the left-hand side that red area is delayed activation where you want to paste that most dysfunctional area. 

And then on the right hand screen, you can see the coronary veins we're able to trace out and superimpose on MRI findings with scar, that red area apexes is the scar. So you can use that to determine how well you're doing and which for example quadripolar pacing poll you want to use. 

And here's a new idea. I wanted to just mention this, particularly in the case of imaging patients with devices, is use CMR to assess programming. So I've talked to you about how you can use-- how you want to change device programming before the patient goes into MRI. Or you want to put them into asynchronous or dependent and things like that. 

But let's take this to a new level, right? So with CRT you can paste from different vectors. You can paste from both leads, both the right and left ventricular leads, or you could paste from the left ventricular lead only and infuse with the intrinsic conduction. Which one of these is better? 

So after yo figure out where you're going to implant the wires, how do you pick the best configuration? Echocardiography is very accessible, but has more noise. And MRI gives us the most detailed information about the cardiac structure function. 

So what we have here is a experience then where we scan the patient at their one setting. And then we take the table out of the scanner, and we have the programmer right there. And then we reprogram the device at a different setting. And then we put them back in the scanner and test the other setting. 

And we typically do two or three, and then we can get these really nice MRI data. As you can see here, the quality is great. We have some protocols including having them raise their left hand above the above the head, and also, to increase the distance from the device from the heart. 

And then also, picking the right cine imaging modality which may be gradient echo or SSFP. And what I show you here are our density plots of remodeling across the patients for both the right ventricle and the left ventricle. As you know, with ECHO an MRI is considered definitely better than ECHO for assessment of right ventricular function. And you can assess biventricular remodeling. 

OK, so that's the end of the content here. I'll just recap. Hopefully we've covered these key points for you. We've talked about the benefits and risks of MRI scans in patients with these devices. We've distinguished between MRI conditional and non conditional devices and the impact on clinical care. We've talked about abandoned leads. 

We've talked about precautions for monitoring during the scans. And we've talked about how we can use CMR to guide management. I wanted to just include a number of people up here who have been very involved in the MRI device program and also with the research. And I'm very grateful to everybody on that list. And I'll just leave the frequently asked questions up. That's it. 

SPEAKER: Thank you so much, Dr. Bilchick. So for those of you who are in the room currently, if you have any questions, we just ask that you use the microphone in the center so the Zoomiverse can hear you. And then we are open for questions on the chat as well. 

So we have a question in the chat. Is there some kind of MRI quote, unquote test or safety sequence that can be run on a patient prior to the real image acquisition to help determine safety? 

KEN BILCHICK: So it's an interesting thought and very good, very good idea. I think though, what I would say is that for the majority of cases, we've shown that even with legacy devices in these MR non conditional devices that the scans are done safely. We now have a series of over 1,500 patients and 2,000 patients from MagniSafe and from the Hopkins study. 

Maybe what the question is getting at is these patients with abandoned leads, for example, these areas of uncertainty. What I'd say about that is there's not really a test per se, but you know I think it's about risk modeling. I think you-- and it's about accumulating data. And it's about shared decision-making. 

And I think this is where it's really important that we talk to our patients, that we talk to each other as colleagues, and try to find the best approach for individual patients. Now certainly the patients are monitored, so if you were to see, just to get to that question, if you were to see anything that you didn't like, you can just take the patient out of the scanner. 

SPEAKER: Great. I had a question about the battery depletion. So it seems like that's the one huge issue that's shown in plenty of studies that can cause the reset. When you interrogate the device, at what point when you see the device that you say, OK, this person needs a generator charge before? 

KEN BILCHICK: Thanks. So there are two issues. One is that the power on resets are a little more likely when you have the battery depletion and so the device can revert to undesirable behaviors. But the other is there could be some slight incremental effect on longevity. 

And so if you're just over the edge for ERI, remember, that was the Electric Replacement Index, it could just push you over to now be in that ERI range. So for me. So for me, it's typically if the confidence interval-- you know about confidence intervals, right? 

And so confidence intervals, so if the devices actually have a confidence interval for battery longevity that they don't typically tell you, OK, you have 11 months. They'll tell you, you have somewhere between, say, six months and 16 months. And so I would say, if the lower the lower bound of that confidence interval is within about three months of ERI, then I'm thinking we just send them for sending for generator change. 

We typically in clinical practice, you don't have to wait until that very day that they hit ERI, particularly if they're dependent. And given the uncertainty of when they're going to reach ERI if they're getting close, it's not out of the range of clinical practice to just change the generators. 

SPEAKER: Great. Any last minute questions? All right, great. Thanks so much, Dr. Bilchick.