Melanie Cole, MS (Host): Welcome to UF Health MedEd Cast with UF Health Shands Hospital. I'm Melanie Cole. And today, we're highlighting phrenic nerve stimulator and sleep apnea, state-of-the-art treatments for sleep apnea and heart disease at UF Health. Today, we have a panel with two University of Florida College of Medicine physicians.

Joining me is Dr. Muhammad Ali Syed, he's the Medical Director and Fellowship Director of Sleep Medicine and an Associate Professor of Medicine; and Dr. Thomas Konecny, he's an Associate Professor of Clinical Medicine in the College of Medicine. Doctors, thank you so much for joining us today. And Dr. Syed, I'd like to start with you. Can you tell us a little bit about the prevalence and the high rates of sleep apnea in patients with cardiovascular disease?

Muhammad Ali Syed, MD: Thank you for inviting me for the podcast. I appreciate that. As far as overall prevalence of obstructive sleep apnea is concerned, it is different between male and female gender. In North America, it's between 15-30% in adult males approximately, and approximately 10-15% in females. So, that demographic generates the amount of cardiovascular disease associated with that. And majority of times, it is associated if someone is having sleep apnea greater than 15 times an hour stopping breathing, which means having moderate to severe sleep apnea is associated with cardiovascular risk factors.

Thomas Konecny, MD: I'll perhaps briefly add one of the things that also comes up is the underdiagnosis that many people actually don't know they perhaps have it. Rarely, anyone hears themselves snore, right? So, it's one of those things where, when we looked at just cardiovascular patients, this is one of the unique things that we published some work from our specialized center that probably nearly half of the people or sometimes even slightly more than half of the people who have heart attack actually have sleep apnea, at least mild forms of sleep apnea, and very rarely they know about it. So, it's an interesting tidbit with that.

Melanie Cole, MS: Well, it certainly is. And I know that a lot of times it's the partner. That's why it's an underdiagnosed situation. The partner's the one who mentions, "Hey, you snore" or "You stopped breathing," those sorts of things. But Dr. Konecny, do you think that sleep apnea contributes to cardiovascular disease or that people with cardiovascular disease are more at risk for sleep apnea and other sleep disorders? Are they interchangeable that way?

Thomas Konecny, MD: Well, I think we're at a very exciting time in terms of discovering how exactly they're interlinked. I've been in this business quite some time. And 20 years ago, when we presented our data at big meetings, people were laughing. You know, they're like, "Well, why would snoring and heart attacks or arrhythmias have anything to do with each other?" So, we've come a long way. I think we're discovering much closer links than people thought.

A lot of the treatments and technology is evolving and allowing us to actually hopefully improve some of the cardiovascular outcomes by treating sleep apnea. But perhaps that's why we're excited about our center, because it is a multidisciplinary effort. You know, it takes the sleep physicians, the cardiologists, the electrophysiologists, to work together. And I think we can actually, in the next probably several years or decades, I think we're going to be screening and treating sleep apnea in ways that we were not used to, say, 10, 20 years ago.

Melanie Cole, MS: Dr. Syed, why don't you tell us the difference between obstructive sleep apnea and central sleep apnea so that we have a working definition of what we're talking about here today?

Muhammad Ali Syed, MD: Sure. For obstructive sleep apnea, it's generally happening due to the structural narrowness in the back of the throat, which means that when the airway is getting blocked, it is causing people to stop breathing when they're sleeping. Generally, that is the obstructive sleep apnea. As far as the central sleep apnea is concerned, what tends to happen is that the brain is not sending the signal to breathe. So if the brain doesn't send the signal, what ends up happening is that no air is moving inside the body. So, the difference is that the patient is not having any ability to breathe at all. Whereas an obstructive sleep apnea patient has the ability to breathe, but it is not passing through the airway canal.

Melanie Cole, MS: Thank you for that. And Dr. Konecny, as we're learning more and more, and we can get into diagnosis a little bit, but I'd really like to speak about some of the limitations of traditional treatments for sleep apnea in cardiovascular patients. So, why don't you start with diagnostic criteria and how you're getting people into the office, really, how you're diagnosing this, and then we can talk about some of those limitations of the traditional treatments that we've been hearing about for years?

Thomas Konecny, MD: Absolutely. That's a great topic actually to tackle. A lot of people who do have heart disease are very much motivated to do something about it, right? We know some things that we can influence and some things we cannot. If people come to my office, I specialize in arrhythmias such as atrial fibrillation or other types of electrical disturbances in the heart. When they come, nearly everyone asks, "What can I do differently to improve things?" Well, it's hard to get younger, right? I mean, it would be great because age is a major determinant, but we're not going to accomplish that. Many people already stopped smoking or they're in the process of it. Many people are working on their blood pressure or cholesterol, kind of the more commonly known things, right? So, that's where I think sleep apnea comes in, because it is one of the modifiable issues that many people have that's, as Dr. Syed pointed out, is highly prevalent.

So, probably in my office, likely more people than not have at least a mild form of sleep apnea, which of course can go hand in hand with other risk factors, perhaps a little bit of extra weight, a little bit of deconditioning, increasing age, and all those factors. So once we get to how to improve things, that sleep apnea is actually one of the most appropriately modifiable factors. I will talk perhaps about our new programs and evolving programs, because really it is our belief that it takes a specialized place that provides really state-of-the-art expertise from multiple fields to be able to appropriately personalize the care.

 One person may snore, one person may snore and have a heart attack, perhaps related to it or have arrhythmias from it. And how do you differentiate them and how do you treat them appropriately? So, I think that's where perhaps our UF strength really comes in, is that we can say that we're at the forefront of what's currently known and perhaps even leading the way at some future possibilities for the exciting treatments, including the phrenic stimulator, which we're excited to offer to patients here.

Melanie Cole, MS: Dr. Syed, why don't you expand on how sleep apnea management intersects with heart disease treatment at UF? And tell us about the phrenic nerve stimulator and how these two collaborations, as Dr. Konecny mentioned, the multidisciplinary approach and collaboration at UF Health, why don't you expand on that for us?

Muhammad Ali Syed, MD: The whole idea behind it is to reduce the risk of further complication with patients. So, one of the things that I wanted to point out that majority of times, central sleep apnea, which is more of a brain not sending signal is due to multiple reasons. The most common reason that we see in our patients is heart failure. Heart failure is more common in males. We tend to see more common in male patients with CHF and more specifically central sleep apnea. However, it can also happen due to certain medications, certain issues in regards to if someone is living in a high climate, high altitude. When someone is having heart failure, generally what tends to happen, if there are different modalities of treatment for treating obstructive sleep apnea and central sleep apnea, majority of time people would have combination of things, not just having central or not just having obstructive, they might have combination of things.

However, due to certain limitations of central sleep apnea management from the positive airway pressure therapy, suggests adaptive cerebral ventilation, which is a special kind of a machine, patients who have central sleep apnea can be placed on these kind of machine. However, there is a SERVE-HF trial that indicates that someone who's having a pump function of the heart less than 45, they're not a good candidate. So, what those patients will do then? Those patients are very ideal candidates for treatment for central sleep apnea by transvenous phrenic nerve stimulation, which is a remedy device. And this is a device that we are actually currently using to help those patients who have nowhere else to go, because this treatment is not available anywhere else in northern part of Florida.

So, what we are trying to do is to provide them care in a fashion, which reduces the risk of their further complications and also reducing and making their life much more comfortable in a sense reducing the excessive daytime sleepiness by the treatment of management of central sleep apnea?

Thomas Konecny, MD: Perhaps I'll contribute as someone who is on the side of actually placing these devices, where we just do that in the electrophysiologic laboratory, one thing that perhaps may be interesting to many physicians or persons who might be listening, is that the phrenic stimulator really does something that we haven't been able to achieve in pretty much history of medicine. When we have someone who's has a tough time breathing because their respiratory drive is insufficient, their brain is not telling them to take a deeper breath enough. In the past, we would generally have them put a mask on and press some air into it with positive pressure options. But this is really the first time when we can do what physiologically the body does, which is we actually stimulate the phrenic nerve, which is it pulls down the diaphragm. And actually, the person takes a physiologic or nearly physiology breath sort of in, rather than us pushing the air inside their lungs.

why does that matter? Well, this is one of those things, both Dr. Syed's group and our group is highly interested in studying. Because for some patients, especially patients with heart failure, they may not actually be as well positioned to tolerate that positive airway pressure, which traditionally used to be applied. And perhaps it is these phrenic nerve stimulators that uniquely allow for more physiologic and natural breath for the patients to take at night when they're sleeping.

Melanie Cole, MS: Dr. Syed, how does the efficiency of what Dr. Konecny was just discussing compare to other treatments that we've heard about over the years, CPAP, Inspire, tell us how would you compare them?

Muhammad Ali Syed, MD: As far as transvenous phrenic nerve stimulation devices is concerned, they're actually following a five-year prospective study. And they've shown patients who were having central steep apnea while they're on treatment have reduction of their central sleep apnea from .80 to 1. So, that's a significant indication that what the device is doing is doing its job and is helping patients in improving the quality of their life. So, these two things stands out, what other devices are not able to do and what phrenic nerve stimulator is able to do that. That's number one.

Number two, patients who are intolerant to any kind of PAP therapy, who do not like to have any mask, or do not want to wear anything over their face due to multiple reasons. This actually helps them to get away from that and helps them to treat the central sleep apnea management from that. Yes, there is some residual obstructive sleep apnea. But what we have seen right now in our current patients that we have implanted, they're doing a really good job in actually improving in their excessive daytime sleepiness, despite of having some residual obstructive sleep apnea, their central sleep apnea has improved, so they are more awake. So, I think it definitely improves the quality of life and helps in reduction of other risk factors of cardiovascular disease.

Melanie Cole, MS: Such an interesting conversation and really enlightening. I'd like to give you each a chance for a final thought here. And Dr. Syed, are there any ongoing research initiatives at UF exploring this link between sleep apnea, heart disease? What would you like other providers to know about the work that you're doing at UF Health?

Muhammad Ali Syed, MD: Yes. We are actually collaborating with Cardiology with Dr. Konecny, and we are trying to actually see the heart rhythms that we are trying to monitor them and try to see what the impact of the duration of certain segments of the EKG would have an impact in future to see if there's any correlation between what will tend to happen in patients and their high risk of developing cardiovascular complication later down the road. So, that's one aspect.

The other aspect that we're working with is the phrenic nerve simulation to help our patients for treatment for central sleep apnea. And we are in the process of developing a protocol so that we can see how these patients do in a long-term basis.

Melanie Cole, MS: Thank you for sharing that. And Dr. Konecny, last word to you. What would you like other providers to take away from this very important discussion that we're having today about that link between cardiovascular disease and sleep apnea, sleep disorders, and kind of going back and forth between those two, the key messages here.

Thomas Konecny, MD: I think it's probably two things. One of them that this is really a very specialized arena. And if one is concerned about patients with this, it really does pay to send them to a specialized center. I would also argue that ours is one of the leading ones, not just locally or in our nation, but even in the world. We are the leading authors on the main chapters on these topics in the main electrophysiology textbooks. And we have many ongoing trials, which for the sake of time, I won't go into details. As Dr. Syed pointed out, we're looking at some of the arrhythmias and ECG changes during sleep apnea.

But let me also highlight a more patient-centered version of this, which is I have to compliment the sleep medicine team at UF for doing unbelievably great job at following these patients, titrating their therapies and working on these devices. Because, see, when I place a phrenic nerve stimulator or send our patients, it's utmost to me that we do it safely with the utmost expertise. But then, there is years of followup that has to be done diligently and very, very in a personalized nature. And I think that's particularly the strength of our collaboration.

Muhammad Ali Syed, MD: I will second that, and I think this is a unique collaboration that we have it is the way that we have designed this system that we keep patient first and make sure that their safety and their health is number one priority for us.

Melanie Cole, MS: What a comprehensive approach and multidisciplinary. It's so important. And, Doctors, I want to thank you both for joining us for this lively discussion today. And to learn more about this and other health care topics at UF Health Shands Hospital, please visit innovation.ufhealth.org. And to listen to more podcasts from our experts, you can always visit ufhealth.org/medmatters. That concludes today's episode of UF Health MedEd Cast with UF Health Shands Hospital. Please always remember to subscribe, rate and review UF Health MedEd Cast on Apple Podcast, Spotify, iHeart, and Pandora. Until next time, I'm Melanie Cole.