Melanie Cole, MS (Host): Welcome to the podcast series from the Specialists at Penn Medicine. I'm Melanie Cole and today we're highlighting AFib and stroke prevention. Joining me is Dr. Alexander Bridges. He's a Cardiac Surgeon with Penn Medicine. Dr. Bridges, thank you so much for joining us today. I'd like you to start by speaking a little bit about the prevalence of AFib, the scope of what we're discussing here today, and really the main complications that we're trying to mitigate when we think about treating AFib.

Alexander W. R. Bridges, MD: Well, good morning, Melanie. Thanks for having me on. It's a pleasure to be here. AFib is something that's, you know, near and dear to our practice. It's something we treat a lot. That's true I think of all cardiac surgery practices probably worldwide. It's an incredibly common disease. We see it all the time. Depending on the reason the patient's being referred to the practice, coronary disease, valvular disease, multi-valvular disease, the incidence of AFib that we see can vary significantly. The lowest incidence we see in, in coronary patients, kind of in the call it about 10% range, and then it rises all the way up to, to maybe to 50 - 60% range for patients who have multi valvular disease, particularly mitral valve disease.

The incidence of AFib rising in the population. That's been known For the past few decades, seems more, you know, every year the incidence seems to increase by sort of three, four, 5%. A lot of that is probably an aging population. A lot of that is increased aging population, but a lot of that's also probably just, we're looking for it more, we're finding it more, we're doing more long-term rhythm monitoring. And AFib is one of those diseases that the more you look for it, the more you'll find it.

Host: Well, that's certainly true, Dr. Bridges. So when we think of the complications, we hear about stroke and we're going to talk about the treatments to try and mitigate that risk. But there are long-term complications and consequences if it's not found. So I'd like you to speak please, about those complications and diagnoses because as you said, the more we look, the more we'll find, but sometimes it's found incidentally, sometimes patients don't know at all. Speak a little bit about that.

Alexander W. R. Bridges, MD: So I'm glad you mentioned stroke. You know, One of the absolute most important parts of workup for anybody presenting with a new stroke is to look for heart rhythm abnormalities. And we also will usually get an echocardiogram and look for structural heart abnormalities, which can be associated with the rhythm or independent.

Sometimes we find primary valvular lesions leading to a stroke. But a lot of the time, the truth is we find that the patient has AFib and a lot of the time they haven't known. They're not on any antiarrhythmic therapy, they're not on rate control therapy, they're not on blood thinners. It's a new diagnosis of a stroke and a new diagnosis of AFib, both at the same time.

So that's the one that's on everybody's minds and it's incredibly important. That factors for us very strongly into what we do during open heart surgery, particularly with management of the left atrial appendage. Anybody presenting for an operation who has a history of AFib should absolutely standard of care, have their left atrial appendage addressed specifically to reduce lifetime risk of stroke.

But as you pointed out, that's just one of the complications that can occur. The other things that we think about all the time, or the thing really, is the long-term risk of heart failure. A substantial proportion of patients with atrial fibrillation will go on to develop what we call a tachyarrhythmia-induced cardiomyopathy, a fancy term for basically just the heart's getting chaotic signals, rapid signals, and it actually leads to a significant decline in heart function.

This is something we see all the time. We see it really often in patients who have valvular disease as well. But we also see it in patients who have no valvular disease and one can lead to the other. Patients who have atrial fibrillation for a long time develop structural changes in their heart that can actually predispose to valvular disease.

More often, we see it the other way around, that a patient who has a structural valve disease, mitral regurgitation, mitral stenosis, that leads downstream to atrial enlargement and subsequently to atrial fibrillation. But We do actually see it going both ways. So fundamentally, the things we're trying to avoid are stroke, and we're trying to avoid heart failure.

Host: Well, thank you for mentioning that, that it does go both ways. And so when we think of treatment, what problems are you trying to solve Dr. Bridges? Are we looking to cure the AFib or reduce the risk of stroke, rate control, anticoagulation? It's really an interesting medical treatment paradigm.

There's so many different tools in your toolbox now, and we're going to talk about some of those. So Speak a little bit about what you're trying to achieve and some of the options, ablation, there's a lot of things out there today. so speak about some of those.

Alexander W. R. Bridges, MD: So, if you take the AFib as a disease that requires both medical management and occasionally invasive interventions, ablations, left atrial appendage ligation; if you think about it as a whole disease process. Our goal is to cure it. Ideally, our goal is to make it go away.

So a patient had AFib, so the patient no longer has AFib. Our goal is to cure AFib, stabilize a patient's heart rhythm. And in so doing, reduce their lifetime risk of stroke and heart failure. Some patients need a lot of interventions to make that happen. Some will need a few. There are lots and Lots of patients who get started on antiarrhythmic therapy and their heart rhythm remains stable for a long, long time.

There are patients who get a single episode of an ablation, percutaneous, done with a catheter by a cardiologist, for example, the electrophysiology division we have here, and get a durable lifetime cure. And then there's others we see in the operating room where we do a procedure, a maze procedure, for example, or some components of a maze procedure, and similarly cure them.

That's what we're going for. We're going for cure. If cure can't happen or if achieving the cure is considered too invasive; maybe a patient doesn't want to undergo an open heart operation just to address AFib, and there's no other reason for them to have open heart surgery, then long-term management is the goal.

We want to keep a patient's heart rate normal. We want to keep a patient's heart rhythm normal, provided that the effects of the antiarrhythmic drugs aren't basically not worth it, and we want to reduce a patient's risk of stroke with a blood thinner, by addressing the left atrial appendage or both.

Host: So, over the years, oral anticoagulants have been an important therapy. Not everybody wants to be on them for life, and those have evolved over the years as well. But I'd like you to speak about some of the surgical options, the interventional options that make it so that patients don't necessarily have to be on those oral anticoagulants for the rest of their life.

You know, the Cox-Maze procedure, the Watchman. There are all sorts of things today. Speak about what you're doing there at Penn Medicine.

Alexander W. R. Bridges, MD: Yeah, So, this is a topic of ongoing research, ongoing debate, and very collegial discussions between cardiologists, primary care providers, and cardiac surgeons. And I don't think anybody knows exactly the right answer. The Cox-Maze procedure was developed back in the 1980s, at Duke and at Wash U. James Cox really published first in about 1987, a series of patients where he had done open heart surgery and they had done what's called a Cox-Maze 3 procedure, what we now call the cut and sew Maze procedure, which was basically deconstructing the atria, cutting it into multiple pieces and then stitching it back together.

In the process, the left atrial appendage was taken away completely, so that was gone. But otherwise, the atrium was basically put together, but all of those suture lines, all of those cut lines evolve into scar tissue. And then what we call these macro reentrant circuits, and these trigger points were excluded.

So basically the atrium could only hear and could only transmit normal signals in a normal way. And that procedure remains really, I think a lot of people would still refer to it as the gold standard. It cures AFib well over 90% of the time. And patients are free from not only AFib, but they're free from being on antiarrhythmic drugs.

And at that point, there's really not a compelling reason, at least we would think for a patient to be on an oral anticoagulant. If you do less than that, then we start to get a little bit worried that a patient in the absence of an oral anticoagulant drug still has a meaningful risk of stroke. Now we're talking low single digit percentage, yearly risk of stroke, but that's not nothing.

And as oral anticoagulant therapy has become safer and safer, that risk benefit calculation, that risk benefit comparison is sort of a moving target, and that's actually for us, one of the exciting parts of the field is trying to figure out for each individual patient where their particular risk benefit calculation says, okay, yeah, you know, it's worth you being on an oral anticoagulant even though you've had a maze procedure, even though your left atrial appendage has been ligated.

There are some studies showing that for patients who have various different heart rhythms and present with a stroke, within 30 days, they've been shown not to have a clot within the left atrial appendage. So if you take away the part of the heart that is considered to be the most risky, you can still develop a clot within your heart.

So that need for the oral anticoagulants really hasn't gone away. But having said that, if we take a patient with a low burden of AFib, so having said that, if we do a curative operation, meaning that we do, let's say a full Cox-Maze procedure, we exclude the patient's left atrial appendage, and then we monitor their heart rhythm over the next year and show that they're not having any recurrent episodes of AFib, we, in the cardiac surgery community think there's a compelling argument for those patients to be able to walk away from the oral anticoagulants completely—but that's a conversation to be had also with their cardiologist.

Host: Isn't that interesting? And that is such a discussion among cardiac surgeons, cardiologists, and healthcare providers. So let's speak about the patient experience. If you have done a left atrial appendage closure device, or the Cox-Maze, you've done one of these and the patient is doing well, what then, what is their follow up like? Speak a little bit about quality of life because isn't that really what this is all about?

Alexander W. R. Bridges, MD: It is. You know, And quality of life surveys continue to show, they're shown for decades and they continue to show that patients with AFib have a lower quality of life and patients who had AFib with a lower quality of life and then have their AFib fixed, have a better quality of life. So it really is meaningful, not only in terms of decreasing, hopefully potentially medication burden.

Hopefully in certain cases, getting patients off their oral anticoagulants, reducing risk of stroke, those are all good things too, but patients feel better. So, the patient experience really has a lot to do with how much AFib they're having coming in, whether they've developed heart failure, and whether they're needing a minimally invasive procedure, for example, a Watchman device, a percutaneous ablation, or whether they've needed open heart surgery. For example, in the US today, every year about a thousand isolated Cox-Maze procedures are performed every year. Those numbers are maybe five, six years old. Perhaps the incidence has gone up a little bit, but only about a thousand people are going to the operating room just for a Maze procedure every year. But tens of thousands of patients have a Maze procedure done while they're also having another open heart surgery performed. So we do a lot of Maze procedures, and we see a lot of patients recover from them. And we see routinely that the patients who are out of AFib have a simpler, more straightforward recovery. They have fewer follow-up appointments and they feel better.

So they're still recovering from open heart surgery. You know, let's be clear. That takes a week in the hospital. They go to cardiac rehab, they're recovering for a few months. But you can tell that when you've gotten them back into a normal rhythm, things are simpler, things are more straightforward, and patients feel better. On the other end of the spectrum, when a patient comes in for an ablation, well, these are done as outpatient procedures by the cardiologists, and that's just fantastic when that can be done.

Host: Well, it certainly is. It's a pretty exciting time in your field and Dr. Bridges, one of the more important things when patients do have AFib, whether they're on medication or have undergone an intervention, is the multidisciplinary approach. Because there are other providers involved. Maybe they have to learn more about exercise or nutrition or weight loss or any number of cardiovascular positive type things. Speak a little bit about your team and all of the providers that might be involved helping a patient navigate the world of AFib and stroke prevention.

Alexander W. R. Bridges, MD: No, absolutely. And I'm glad you mentioned some of those things in terms of weight loss, exercise. If you look at the list of risk factors for AFib, number one risk factor, by far overwhelming everything, is age. Nothing we can do about that. But going down the line, the next risk factors are hypertension, coronary disease, obesity, diabetes, sleep apnea.

Every single one of those things, as we all know, are intimately associated with exercise, with nutrition, and with compliance with the newer medications. So all of this really does fit together. When we meet a patient who has metabolic syndrome or all of the typical risk factors for cardiovascular disease, those are the same risk factors for that patient developing AFib down the line. So, from a primary care and preventative care perspective, it couldn't be more important. In terms of a multidisciplinary approach, you know, at, at Lancaster we're very lucky. The electrophysiology department here is absolutely fantastic.

They've been leaders in the field, and we have an extremely collaborative relationship. So when a patient goes to see one of the electrophysiologists, if they feel the patient would be best served by a surgical left atrial appendage procedure, or by an open Cox-Maze procedure, or with one of those things in addition to another heart surgery, they send them over, they call us. We know right away. We get you taken care of in, like you said, in a multidisciplinary fashion. When patients are being worked up for what feels like an unrelated procedure, maybe a transcatheter aortic valve replacement, something like that, but if the patient has AFib, that's something to make us think maybe this patient's going to be better served by surgery.

Provided again that the risk-benefit ratio makes sense. So we're collaborative with the interventional cardiologists, the electrophysiologist, general cardiologist, and also the primary care doctor's offices. I think the heart group here at Lancaster General does an absolutely wonderful job of managing that. And, along with us.

So here at Lancaster General, we're participating in a national trial. It's called the LEAPS Trial, and this is a trial to investigate whether left atrial appendage exclusion, left atrial appendage ligation, basically taking away this part of the heart where blood clots can form, is something that should be done more often.

It's a very straightforward and simple thing to do during an open-heart operation. It doesn't really change the approach to the surgery, but we're trying to answer the question fundamentally of if patients who have a lot of risk factors for AFib—those risk factors we talked about hypertension, coronary disease, obesity, diabetes, sleep apnea—but who haven't yet been diagnosed with AFib, should we be doing something proactive at the time of cardiac surgery to reduce lifetime risk of stroke? Now, we don't know the answer to that question, so that's why we're participating in a randomized controlled trial. But anyway, that's something that Our division's very passionate about atrial fibrillation, and about trying to be proactive in helping patients going forward. That's one of the trials we're participating in right now.

Host: Well, thank you for going over that. As we get ready to wrap up Dr. Bridges, what would you recommend, first of all, for patients for whom AFib is largely managed, but who continue to experience premature ventricular contractions or flutters? It's a little bit refractory, but it is managed for the most part. And what would you like the key takeaways to be for other providers about referral, when it's important to refer and what you would like them to take away from this episode today?

Alexander W. R. Bridges, MD: The spectrum of heart arrhythmias, premature atrial contractions, premature ventricular contractions, you mentioned and beyond, flutter, fibs, ventricular tachycardias; it's an enormous field and there really is a concept of expertise in the field. And our electrophysiologists are really just fantastic at that.

Fortunately, premature ventricular contractions, PVCs, which we see all the time, don't appear to be a risk factor for patients developing AFib or going back into AFib, if they do undergo a procedure. Separate mapping procedures can be done, complex ablations within the ventricle can be done. Our electrophysiologists do them here and rarely, and we offer this, we have the ability to put patients on bypass, to stabilize them while more invasive ablations are being done, although that's rarely, rarely needed.

So in terms of the spectrum of arrhythmias for the patients who've got AFib and flutter, and I think the real message is that these are treatable conditions. The treatment needs to be tailored to the individual. The treatment should be tailored to the individual, and it's not that hard to do. Every once in a while, the surgeons do need to get involved with that.

We're happy to help. Patients have an excellent recovery. Quality of life gets better. But certainly if a patient needs open heart surgery for another reason, valvular disease, coronary disease, for example, and they also have AFib, that's absolutely something that should be treated. And I think that should bias patients towards thinking maybe, maybe open heart surgery is something I want to do, because at the same time as these other procedures, these other necessary procedures, we can also get rid of the AFib, we can take care of the AFib, we can reduce your lifetime risk of stroke.

And that's, I think, an important message for patients and providers to hear.

Host: Thank you so much, Dr. Bridges. What an informative episode this was. Thank you for joining us and to refer your patient to Dr. Bridges at Penn Medicine, please call our 24/7 provider only line at 877-937-PENN, or you can submit your referral via our secure online referral form by visiting our website at pennmedicine.org/referyourpatient.

That concludes this episode from the specialists at Penn Medicine. I'm Melanie Cole.