Transcription:

Melanie Cole (Host): Welcome to UAB MedCast. I'm Melanie Cole. And joining me is Dr. William Maddox. He's a cardiac electrophysiologist and an associate professor at UAB Medicine. He's here to highlight current management of atrial fibril. Dr. Maddox. Welcome back. Thank you so much for being with us today. This is such a huge problem. We're learning so much more and it's really, an exciting time in this world of AFib. Can you start by telling us about the prevalence, what you've been seeing in the trends and how treatment of symptomatic atrial fibrillation with rhythm control strategies can really improve the quality of life? And in several patient populations improves hospital rates, mortality, really all of it?

Dr William Maddox: Thank you Melanie, for having me. This is always fun to be on the show and be able to talk about some of the things that we get to do here at UAB. In terms of the prevalence of atrial fibrillation, this is the most common sustained arrhythmia that we see. Today in clinic I have 42 patients in clinic and probably 30 of them have atrial fibrillation as our population in the United States ages, it is going to become more prevalent, certainly with hypertension, diabetes and coronary disease, obesity being more prevalent in our populations, we're gonna see more and more atrial fibrillation.

Symptomatic atrial fibrillation is really an epidemic in the United States. And when I think about taking care of atrial fibrillation, I really think about it as two separate treatment modalities. One is prevention of stroke and the other one is prevention of symptoms. The prevention of symptoms is really a silo into itself. And we can take care of that either with rate control or with rhythm control and certainly with our advances in both medicines and technology over the last 25 years, rhythm control has become a mainstay in first line treatment for patients with symptomatic atrial fibrillation.

Melanie Cole (Host): Wow. That's quite a prevalent condition and I'm glad you mentioned risk of stroke. So I'd like you to speak a little bit about anything new, any game changers in diagnosis. And I mean, obviously since COVID managing diagnosis screening, all of that changed a bit. Can you tell us how technologies played a huge role as far as screening, diagnosing and monitoring AFib?

Dr William Maddox: Sure for many years, we've had ambulatory monitors that patients could wear when they're at home to surveil for arrhythmias when they have palpitations, but with the new mobile telemetry and the new wearables that patients have such as the Apple watch or many of the other, cardio has one, there's several manufacturers. Patients are actually able to monitor themselves at home. And there's many times when I'll have patients in clinic that are referred to me from either cardiologists or primary care physicians with their own strips of atrial fibrillation.

Or what they believe to be atrial fibrillation, either printed out or sent in an email or a PDF. And this allow for patients to be able to surveil for themselves.. And if they do get something on the monitor that looks like it might be atrial fibrillation, they can get that to their primary care physician or cardiologist fairly quickly and easily. And it's allowing us to be able to diagnose atrial fibrillation earlier in the disease process.

Melanie Cole (Host): Certainly has. And so, we hear a lot about the antirrhythmic medications that are available and it many times as a first line of treatment for these patients, but then there's always the side effects, drug interactions, adverse interactions that make the use of them challenging. So before we move on to some of the interventional therapies that you might offer, speak a little bit about what's going on in the medication intervention world right now. Dr. Maddox, what's new, what's changing, what have we found out that we didn't know, maybe a few years ago?

Dr William Maddox: Medications for rhythm control for atrial fibrillation really haven't changed that much in the last 10 to 15 years, we have our same mainstays of medication, including the 1C anti rhythmic, such as Flaco din Perone that we can use in patients with structurally normal hearts. We also have sodalol which is a class three enter would make a potassium channel blocker as well as dofetilide. And then Moltech is a deiodinated form of amiodarone that has some efficacy, although it is not as effective as amiodarone itself. And of course the 800 pound gorilla in the ring would be Amiodarone itself, which has been around for quite some time.

All these drugs have reasonable effectiveness, but they also have a significant number of side effects. And you really have to look at the patient's comorbidities to decide what medication might be best. Some patients can do quite well on some of these medications. In my first line, if someone had the structurally normal heart would be to use a 1C anti rhythmic, such as flacanine or [inaudible]. These do have side effects of fatigue and sometimes some slight vision changes and some patients just don't tolerate it well.

The other medications certainly have bradycardia as a complication, and then there's significant medication interactions with all of them. And so you really have to be careful with what other concomitant medications the patient might be on. So, it is a first line therapy for symptomatic atrial fibrillation for perisismal symptomatic atrial fibrillation, interventional options are becoming more and more first line therapy.

Melanie Cole (Host): Well, then let's discuss some of those because as we are saying, not everybody wants to be taking. Medications and for the rest of their life. And there's many interventions that have come on the scene. So why don't you start with catheter ablation? That's becoming increasingly common with a relatively high success rate and low complication rates. Speak a little bit about that and we'll get into as many as we have time for.

Dr William Maddox: Catheter ablation has been around for 35 years or so in various iterations. And catheter ablation for atrial fibrillation with a view towards targeting pulmonary vein isolation, which means that we create lines of scar around the pulmonary veins to isolate electrically, the pulmonary veins from the rest of the atrial tissue. That has been around for approximately 22, 23 years. Our understanding of the triggers for atrial fibrillation first came out in 99 with paper out of Bordeaux.

And it showed that 94 to 95% of the triggers for atrial fibrillation come from the pulmonary veins. And that has been the driver for the main state of our treatment for atrial fibrillation. Over the years, that ability to be able to target these areas has become safer, more effective and more efficient to the point now that catheter ablation for atrial fibrillation either with cryo ablation using a balloon technology that we can freeze the tissue around the interim of the vein or with radio frequency ablation around the pulmonary veins.

Usually by ablating a line around the Ipsa lateral pulmonary veins, both on the left and the right has become something that we can do in, an hour to two hours of procedural time. Now that's still a, full day procedure for the patient. But about an hour to two of procedural time with a low complication rate, I quote patients a complication rate of about one to 2% with that most commonly being hematoma or bleeding, bruising at the access site in the right common femoral vein.

There are very rare complications, including pericardial effusion, necessitating intervention, pulmonary vein stenosis, stroke of esophageal fistula. Those are dreaded complications, but fortunately are very rare somewhere in the order of one to 500 to one in 4,000.

Melanie Cole (Host): So interesting. Now tell us a little bit about the Watchmen, because that's another one that you know, many providers are talking about. How are you using that at UAB Medicine?

Dr William Maddox: When I talked initially about the different treatment modalities for atrial fibrillation, this really moves into the silo of stroke prevention. And stroke prevention is so important in atrial fibrillation because one in five strokes in the United States are associated with atrial fibrillation. And patients with atrial fibrillation, one of the main stage of treatment is we place them on an oral anticoagulant medication such as warfarin or the novel anticoagulants. Like apixaban tabigotran, ,or rivaroxaban. However many patients can't tolerate blood thinners.

They either have bleeding or have frequent falls or the need for other medications that might interact with the blood thinners. When that's the case, then another treatment modality that we have would be to occlude the left atrial appendage, the left atrial appendage is where thrombus formation occurs. That is the night for stroke. And so currently FDA approved is the Watchman device, the Watchman flex device, which is a night and all basket with Fabric covering that is actually implanted into the ostium of the left atrial appendage.

And over time, the body will build a layer of endothelial cells over the device and close off the appendage. There's also a second device called the Amulet device. That is by habit, that essentially does the same thing with a little bit different technology and, and has the ability to give us more variety in the left atrial appendage that we can treat. There are certainly size limitations to what we can treat and the appendage can't be too small or too large, and there has to be enough depth within the appendage for us to be able to deploy the device.

But for the most part, especially with both of these tools, we can close the vast majority of appendages that are out there. In my last 200 procedures, I think I've had two left atrial appendages that I just couldn't get closed with our current technologies.

Melanie Cole (Host): So your outcomes for these are really great. And so before we wrap up, I'd like you to speak how you're using these procedures. Are you using them along with other adjuvant therapies or standalone? And how UAB Medicine has been involved in clinical trials related to these closure devices, atrial fibrillation, stroke, wrist, anything you'd like other providers to know about?

Dr William Maddox: We have a comprehensive program here for the treatment of atrial fibrillation that includes both stroke prevention and prevention of symptoms for atrial fibrillation and in select populations. As I think you alluded to at the beginning, such as patients with heart failure in atrial fibrillation, there has been mortality benefits for rhythm control strategies. For years, we have been working with industry as well as with government sponsored trials, to look at the most novel technologies that are out there and try to continue to make our procedures safer, more effective and more efficient.

And we have several trials going on right now, looking at the use of left atrial appendage occlusion in patients with lower stroke risk and not really the traditional indications for left atrial appendage occlusion. That includes the Champion AF trial, where if you are on an novel anticoagulant and would like to be considered for left atrial appendage occlusion, we're comparing that to novel anticoagulation with the hopes that it will actually show that it improves outcomes and increases safety.

In regard to studies with catheter ablation, one of the most exciting things that's coming down the forefront is that our mainstay of treatment here is either using radio frequency, which creates heat or using cryoablation, which, freezes the tissue. But we always worry about damage to contiguous surrounding tissues when we do that. And a new treatment modality is something called pulse field ablation, which is actually a DC current that is pushed through electrodes within the heart that allows for ablation of local tissue with very little to no risk of damage to contiguous tissue that's farther away.

We hope that in time will show that this is as effective as our current ablation strategies, but it's much safer because we don't have to worry about the possible damage to the phrenic nerve or the esophagus or surrounding lung tissue. It's an exciting time in the field.

Melanie Cole (Host): It certainly is. And thank you so much, Dr. Maddox, what a great guest. You are such an informative podcast, too. Thank you again for joining us. And a physician can refer a patient to UAB Medicine by calling the MIST line at 1-800 UAB-MIST, or you can always visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast and for updates on the latest medical advancements, just like you heard here today, breakthroughs and research. Please follow us on your social channels. I'm Melanie Cole.