Novel Research Demonstrates Improved Patient Outcomes and Reduced Health Care Resource Utilization: Part 1

Part 1 of Podcast Discussion With Rod Passman, MD, MSCE, FACC, FHRS, FAHA; Suneet Mittal, MD, FACC, FHRS; and Mintu Turakhia, MD, MAS, FACC, FHRS, FAHA

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In this special 2-part series of The EP Edit podcast, Drs Rod Passman and Suneet Mittal join Dr Mintu Turakhia for a roundtable discussion on outcomes and new guidance in cardiac ambulatory monitoring. In the first episode, they discuss the latest advancements in ambulatory cardiac monitoring, highlighting the findings from the CAMELOT study. They discuss the evolution from the traditional Holter monitor to current ambulatory cardiac monitors, including long-term continuous monitors (LTCM) and mobile cardiac telemetry (MCT). Finally, they examine the factors contributing to inconsistent care, from geographic disparities to insurance roadblocks, along with the role of AI and the impact on improved clinical outcomes and patient experience.

Mintu Turakhia, MD, MS: Hi, and welcome to The EP Edit podcast. My name is Mintu Turakhia, and I am the Chief Medical and Scientific Officer at iRhythm Technologies. I am excited to have 2 dear friends and colleagues join me in a roundtable podcast about ambulatory cardiac monitoring as well as monitoring beyond that. We are going to get the state-of-the-art updates on outcomes and challenges in cardiac monitoring, and talk about where we go from here. With me are Dr Rod Passman and Dr Suneet Mittal, and I will let each of them introduce themselves. Please also share with us about where your interest in cardiac monitoring comes from. We will start with you, Rod.

Rod Passman, MD: I am a cardiac electrophysiologist. I am a professor of medicine and preventive medicine at Northwestern University in Chicago. I am also the director of the Center for Arrhythmia Research. My interest in monitoring dates back to my days as a resident and fellow. I was always interested in atrial fibrillation (AF), and what intrigued me was this disconnect between what patients felt and what they were having. That was a source of intrigue and frustration, that symptoms alone cannot really be trusted when you are talking about who has AF and how much they have. In those days, we were really limited in the kind of monitoring that we could do. So, from the days where I started my training to what we have now, the world has really exploded in what the options are. But what I think is still falling behind is how the general medical community views the options for monitoring and sort of fails to see some of the key differences that we as electrophysiologists see every day. So, part of my mission is to try to educate the doctors who refer me patients as well as my patients about how we are going to understand how much of an arrhythmia they have, and how we are going to monitor and take better care of them long term.

Mintu Turakhia, MD, MS: Thank you. What a great pretext to what we are going to be discussing today. I am going to now turn it over to Suneet and let him introduce himself.

Suneet Mittal, MD: Thanks Mintu! I am Suneet Mittal, director of electrophysiology at Valley Hospital in Ridgewood, New Jersey. Like Rod, my interest goes back probably 15 or 20 years, because I trained at a time where we were just evolving from the electrocardiogram (ECG) and standard 24- to 48-hour Holter monitoring to newer technologies such as mobile cardiovascular telemetry monitoring. That brought in all these new issues, such as how do we pick the duration of monitoring, how do we pick different types of monitoring done (long-term Holter versus patient-activated event recorders versus mobile telemetry units), and how many days to monitor. One of the things I learned early was there were incredible variations in care, and the attendings and colleagues who I would work with had very different ways that they even call these monitors, often the same monitor they call differently, how they chose the monitors, and how they were deciding on lengths of duration, was all varied. At any time, if there is a lot of variability, it means that people do not really understand it well. I was fortunate about 15 years ago to have an opportunity in the Journal of the American College of Cardiology (JACC) to give some initial insight into all the different monitoring strategies that have evolved.¹ Sadly, there has not been a lot of evolution in this area. There have not been any new guidelines, and until recently, until we had the opportunity to work on the study you alluded to, I really do not feel we made a lot of insight, and I think it is a wonderful time to talk about this topic, because I think there is a lot of really exciting things on the horizon.

Mintu Turakhia, MD, MS: Thanks Suneet, and let's go to that. I mean, your JACC paper is seminal. It is still used and highly cited. It is probably one of the most visible figures you see today, even in EP talks. I think that is a testament to the fact that a lot of the monitoring, and I would argue even the reimbursement, is anchored into these traditional technologies, right? You probably remember the days of having audio cassettes that patients had to keep changing as they were recording Holters in these old devices, and taking down people's credit cards and driver's licenses in the Holter lab when they lent out the capital equipment from the hospital. So, the models have changed, but to your point, you provided that overview, a little has changed in some ways, a lot has changed in other ways, but at the same time, it is 2024, the last guidelines were in 1999, and the Heart Rhythm Society (HRS) was still called the North American Society of Pacing and Electrophysiology (NASPE), and we have not seen anything. So why is it that we have high variation in care and no new guidelines? What has been missing? We have guidelines that get updated every 5 years for everything else, and we have gone a quarter century.

Suneet Mittal, MD: So, there are a lot of factors that go into that. The first issue is that there is a lot of geographic variability in the types of monitors that are available. What is available in the United States may not be available outside the United States, and guideline writers have been very conscientious of recommending things that may not be available in other geographies. The other big issue, especially in the United States, is there are major reimbursement issues related to different types of monitoring that are poorly understood. Some types of monitors are covered by certain insurance carriers, some are not. The net result is it leads to incredible variability of care, and that includes duration of monitoring for anywhere from 24 hours to 30 days, the type of monitoring (standard Holter monitoring, long-term Holter monitoring, or mobile cardiac telemetry monitoring). Worse, patient-activated recorders or auto-triggered loop recorders are still being used. What I feel sad about is that the people ordering these often do not understand the differences in the data that you will get back from that, and that can truly impact patient care, and that is the issue that we have been trying to investigate further to give our colleagues a little better direction on how to handle this. 

Mintu Turakhia, MD, MS: Yes, that is a great point.

Rod Passman, MD: I would argue too that one of the pieces of the puzzle that has been lacking is we have really not had great data to show these advances in technology have resulted in better care for our patients and better outcomes at less cost. So, I think it is not enough to say, yes, we have something better that can record your rhythm long enough. We needed to prove that those advancements translated into the hard outcomes that we all care about. 

Mintu Turakhia, MD, MS: So, Suneet, if you can break down, just for our listeners, the different monitors and how you think of them, and it really extends upon your work from JACC 15 years ago to where we are now. Can you break down the different categories and what they do, and their strengths and weaknesses? 

Suneet Mittal, MD: Yes. So, the way I think about it is as a spectrum; on one end of the spectrum is a 12-lead electrocardiogram (ECG) that patients are very familiar with in a physician's office and gives us a 10-second snapshot of time, and on the other end are implantable devices, whether it is loop recorders or pacemakers or defibrillators that can give years of single-channel data on what's happening with patients. But what we are really talking about is the middle here, and that middle extends from what we used to call patient-activated event recorders, which today almost always is some smartphone-based device that can allow patients to record symptoms of some type. So, the way we use that is when a patient has intermittent symptoms of something, they can basically pull out this device and record a spot 30-second ECG check that is stored as a PDF file that can be shared with a health care provider to determine if something is there. It is not going to tell you information about asymptomatic arrhythmias, and it is not going to give you information about duration of episodes, burden of information, or things like that. The next is Holter monitoring, and Holter monitoring has had 2 big evolutions. One is the duration of monitoring has gone from 24 hours to now 7 to 14 days is pretty much a routine. The second issue is that we have gone from wired systems to essentially patch-based systems, and this has really brought tremendous patient acceptance with this new form factor. Now, this allows us to really get more granular data, we can get longer term data of course, but by looking at every QRS complex during that time, coupled with very sophisticated artificial intelligence (AI)-based data analyses, we can get information about whether arrhythmias are present. If they are, we can quantify these arrhythmias, and we can determine the frequency, burden, and duration of these arrhythmias. The downside of these is that you have no information about what these devices are storing until the device is removed and analyzed. So, if your interest is in knowing what is happening as a patient is being monitored, then you need a new device called a mobile cardiovascular telemetry device, in which the same form factor can be used to wirelessly offload ECG signal. There it is a little more complicated because there are some insurance issues related to this, but for the first time we are learning that they might come at a cost of data loss. We may not get the same data integrity as we are getting with Holter monitors, and so this is what we are trying to get out to physicians that you must really start bringing in all these factors to identify the right device for the right patient. 

Mintu Turakhia, MD, MS: There are some important points here, and Rod, I am going to give this to you, but what you described are many degrees of freedom in the design of this. I think if you go back to the days of the audio cassette Holters, it was purely based on storage. It was whatever you could get on that 60-second audio cassette, and you had to keep doing it, so 24 hours, which was probably a major advancement at the time. Now, memory is cheap, and you can go on forever in the ways that you said. I think this point you are making is now the technology has caught up to the clinical need. So, you have Holter monitoring, which used to be 2 days, and now we can go up to 14 days. We generally call that long-term continuous because Medicare, for example, likes to refer to the sub 48-hour as “Holter.” There is mobile cardiac telemetry (MCT) and the way that it is designed with algorithms, but again, you may not get the full continuous data underneath. Then, a more extreme example of that is event. So, you have all these things that people can pick and choose from off the shelf, and physicians may not know. So, Rod, as you think about that and its relevance to outcomes, how were you thinking about approaching this with the Cardiac Ambulatory Monitor EvaLuation of Outcomes and Time to Events (CAMELOT) study, for example, or looking at a slice of America to see what is happening? 

Rod Passman, MD: I think that what CAMELOT is, and this was a paper published in the American Heart Journal last year,² it has some really unique points that deserve to be highlighted. This is a study of 100% Medicare claims data, really 290,000 patients from across the country. The first thing that was quite striking to me is what kind of monitors people are getting. Despite all the advances in technology that we are talking about, still more than half the monitors used in this country are Holter monitors, lasting for 24 or 48 hours. We know as practicing physicians that if you get your answer in those 48 hours, that is wonderful. But the chances of getting your answer in that 48 hours are going to be much less than a longer-term monitoring. So, I think that getting a snapshot of what we are doing as a medical community across the country was really important. But what to me was most illuminating was that we had the opportunity for once to see what the outcomes were. What is the likelihood that we get a diagnosis with a particular type of monitor? What is the likelihood that you do not get a diagnosis and are going to then have to repeat a longer term or another short-term monitor? How likely are we to impact health care utilization once we learn that information? So, this was a really unique opportunity to do that head-to-head comparison that has been lacking and maybe is a reflection of the fact that the guidelines have not been updated in 20+ years. 

Suneet Mittal, MD: I want to add that I will take the reverse view, which is that Rod is absolutely right that over half the people were still getting a Holter, but the contrary view is that almost half the people were actually getting a long-term continuous monitor or mobile cardiovascular telemetry monitoring, which goes to your initial question: how are people choosing that if it is not even in the guidelines? So, what a miss that there is technology available and is being used, but it is being used without any professional guidance on what the difference is. I suspect that most people are basing their decision on long-term Holter and mobile cardiovascular telemetry on factors that are not really data driven. I think one of the really key benefits of this study is to finally fill those missing gaps and start to put some data behind these choices that people are clearly making in the community when they are treating hundreds and thousands of patients. 

Mintu Turakhia, MD, MS: Great points. So, given that and the fact that there are almost 300,000 patients in this observational study, and it is a single-payer study. So, to the extent possible, you are minimizing payer heterogeneity. Now, there was a difference between local coverage determination and national, as you all know, for Medicare. But still, this was a pretty clean slice of Medicare. So, given the high proportion of use for Holter and mobile cardiac telemetry, in some ways, those often bracket the many options in the middle to your comment earlier. What did you learn? What were the clinical outcomes you thought were worth evaluating here that had value? How do you think that may inform outcomes based on what you found? 

Rod Passman, MD: I think one of the surprising results was that long-term cardiac monitoring was the method most likely to give you a diagnosis, much more often than short-term, which we might expect, but also more often than mobile cardiac telemetry, which can be somewhat surprising. But I think it speaks to the fact that we do not know how much data we lose. They may be very different patient populations. So, not only do you get a higher yield with long-term cardiac monitoring, but because you get a higher yield, you are much less likely to have to require a subsequent monitor to try to get a diagnosis. 

Mintu Turakhia, MD, MS: That is well said. I think just to clarify, by long term, what we mean is up to 14 days, but exceeding the Holter window of 48 hours, finding greater diagnostic yield or encounter diagnosis, as you said, across this. Did that surprise you, Suneet? Did you expect that?

Suneet Mittal, MD: First, I want to level set a little and build on Rod's point, and to answer your question even further, which is, what were the endpoints that we thought would be meaningful? I think we agreed that 3 would be pretty meaningful. One is, of course, did you make a diagnosis? Ultimately, you are doing this to make a diagnosis. Within that first 3-month period of applying this monitor, were you more likely with one type of monitor than another to make a diagnosis? The second thing, of course, is there are economics and patient time and effort that goes into these monitors. What we do not want is the need to repeat the monitor. Do you need a second monitor because the first one just did not yield a diagnosis and the patient is still having symptoms. So, we thought that it would be pretty important to assess out to 6 months the need for a second monitor. The third is, of course, we all live in a time where health care utilization is pretty important and we were really looking to see what the impact on health care utilization would be, emergency department (ED) visits and other things, because economics are really important. I have to tell you, I was surprised by the finding, because the first finding was that clearly long-term monitors, which as you have mentioned several times, typically only go out to 14 days, had a higher diagnostic yield, less likely for repeat testing, and less health care utilization than mobile cardiovascular telemetry monitors, which have historically gone out to 30 days and have people have thought or associated with higher diagnostic yield just by the duration of monitoring. That was a really eye-opening finding for me. 

Rod Passman, MD: I would add that the extent of those differences is pretty impressive, because long-term cardiac monitoring was about twice as likely to get a diagnosis as Holter and maybe about 30% were likely to get a diagnosis than even MCT. So, the numbers were not small, they were quite dramatic. I also think that we need to be careful when we are talking about utilization, because getting a diagnosis actually may generate more tests and more invasive procedures. That is not a bad thing. If you find someone with bradycardia due to syncope and put in a pacemaker, yes, that may go against you in terms of health care utilization. That is a really useful piece of information that we found and a very useful reaction to that information. 

Mintu Turakhia, MD, MS: That is a good point. Let's dive into each of these in a little more detail. So, diagnostic yield, what I thought was so clever about the study and the use of claims, is so often we do not think claims data is great for a lot of things. We have had these discussions before. Observational studies have their limitations. But in this case, the goal was an encounter diagnosis. Someone that documented this on a visit after testing. To your point, that becomes really meaningful. Maybe alone, it is not enough, but there was also another element which was the second outcome, which is retesting, right? So, all these things kind of lined up with each other, which I thought was very interesting. There was more encounter diagnostic or greater risk-adjusted odds of encounter diagnosis with LTCM, as you said, but that also mapped to having lower retest. So, they seem to all fit together in a consistent narrative. How do you think this informs what people should be doing in terms of their monitoring? So again, patients are different, sometimes one monitor makes sense, sometimes another makes sense. But on aggregate, you saw much greater diagnostic yield and lower retesting, so let’s talk about those 2 things. How should people think of what monitor to select based on likelihood of diagnosis and minimizing retest? Because, again, the goal is to get to a diagnosis for a patient as soon as you can. 

Rod Passman, MD: Well, let me just expand on what you said, because I think there are some additional features. Part of that is compliance. I mean, we would love to have people wear something forever, but people are not going to do that. Suneet and other people have done studies showing that you may ask someone to wear a monitor for 30 days, but a lot of those people, in fact, probably the majority, are not able to do that. So, I think when you talk about what is going to be best for diagnostic yield, which is going to be best to minimize my need to retest, it is what is my patient going to be able to be compliant with and not throw this thing back at me after a day or so because they cannot perform their activities of daily living, such as showering or swimming, and do all those things that make it worthwhile. So, I think that needs to be brought into the equation as well. 

Mintu Turakhia, MD, MS: That is a great point.

Suneet Mittal, MD: Yes, again, I think in addition to a form factor, obviously making sure that the device is on because without that there is actually no data of any kind that is meaningful. I really think that this is the first time that we can introduce the concept to people that the choice of monitor matters. I think that is a really big deal, because until this study was done, we had no such data. For lack of a better word, I often felt that these products had become highly commoditized where people thought that ordering one is the same as another, and it was really based on local practices and variables that were not really data driven by the science. Now, this allows us to introduce into the conversation the importance of looking at the data. I think these are 3 meaningful endpoints that resonate with virtually every end user of the product. 

The transcripts have been edited for clarity and length.

This content was published with support from iRhythm Technologies.

Episode 2 coming soon!

References

1.     Mittal S, Movsowitz C, Steinberg JS. Ambulatory external electrocardiographic monitoring: focus on atrial fibrillation. J Am Coll Cardiol. 2011;58(17):1741-1749. doi:10.1016/j.jacc.2011.07.026

2.     Reynolds MR, Passman R, Swindle J, et al. Comparative effectiveness and healthcare utilization for ambulatory cardiac monitoring strategies in Medicare beneficiaries. Am Heart J. 2024;269:25-34. doi:10.1016/j.ahj.2023.12.002