Podcast transcript
Let's start our conversation today just to get a baseline of who the typical AFib patient is.
There are a variety of patients. The very typical patient in my practice has multiple risk factors for atrial fibrillation. So we have to know those risk factors, and generally those are patients who have either other cardiac conditions or are obese, have diabetes, have hypertension, have sleep apnea or are not particularly active. So those are the classic risk factors for atrial fibrillation. However, there is a subset of patients with atrial fibrillation that do not have those risk factors. We see people as young as 20 or 25 years old who have atrial fibrillation. Sometimes those patients have other underlying rhythm problems that causes or precipitates atrial fibrillation.
We see young, healthy women or men at any age with atrial fibrillation where there's no immediate identifiable cause for the atrial fibrillation. So anybody can have atrial fibrillation. It even happens in high-performance athletes who have what we call a high vagal tone. Perhaps one other subgroup to note is our patients with so-called holiday heart after a night out of drinking or celebrating or eating a little too much or drinking too much. Alcohol certainly is a big factor in precipitating atrial fibrillation. And perhaps I should mention lately that we have seen a number of patients with atrial fibrillation with no prior history, who just went through major infections like COVID or other acute illnesses.
Do we have a sense about how many people nationally have AFib?
Atrial fibrillation is the most common arrhythmia in our nation or in other developed nations. It is considered a lifestyle rhythm problem, and comes with a lot of comorbidities that are related to lifestyle or lifestyle changes. It's also an arrhythmia of the aging population. As the population gets older, we do see more patients with atrial fibrillation. It's estimated that 2.5 million of patients with atrial fibrillation are in the United States or are going to be United States by the year of 2025, and that amount is estimated to double within a few years, given that we’re living longer.
We're also seeing more patients with atrial fibrillation because we diagnose it more often. Now that everybody has some kind of a smartphone or a smartwatch or something, we screen many more people, whether intentionally or unintentionally, for atrial fibrillation. So, we do see more patients with atrial fibrillation than we did even 10 years ago.
Can you provide some context on when patients should come in for a consultation with an electrophysiologist?
I've been an electrophysiologist for several decades, and atrial fibrillation has been a rapidly moving target population. Even 20 years ago, the vast majority of patients with atrial fibrillation were treated with all kinds of medications to make sure that their heart doesn't speed up too much, or what we call rate control medications or with blood thinners at the time. But as the treatment for atrial fibrillation has evolved and progressed and we can now offer patients a potential—I hate to say cure, but at least significantly impact the course of the disease and prevent atrial fibrillation from recurring for long periods of time, and some patients may even have atrial fibrillation again with more newer treatment methods—the timing of referral to electrophysiology has been changing. In the past, it was a last resort consultation. If the internist, many of whom are comfortable treating atrial fibrillation, wasn't making any progress or a patient remained symptomatic, then they were sent to a cardiologist, who used all the traditional means of controlling heart rate or shock the patient back in a normal rhythm.
And if that didn't work, then they were sent to an electrophysiologist for consultation to see if they may or may not be a candidate for ablation. And unfortunately, oftentimes that's too late in the disease process. What we would encourage physicians to refer patients with atrial fibrillation early in the disease process, basically soon after diagnosis, to figure out what's the best pathway, what's the best treatment strategy for that particular patient. I mean, every patient is different. Many times you'll just say, “You know what? Let's try to control the risk factors and adopt the wait-and-see approach.” But many times we miss the best time to do a potentially curative procedure.
There have been more recent trials that have shown that if we treat patients with an ablation procedure, for instance, we can delay progression of the disease, even halt progression of disease, and prevent many of the future comorbidities associated with atrial fibrillation. So right now, I would recommend that anybody who's been diagnosed with atrial fibrillation should at least have a conversation with an electrophysiologist once the basic workup has been done, to make sure that their thyroid function is okay, that they don't have a major heart attack or a major heart problem. After basic cardiac evaluation, I think they all deserve at least a consultation or a conversation with an electrophysiologist.
How do you determine which patients may be helped more by medication management versus those who may need a catheter or surgical ablation?
I would say we have to find an individual approach to every patient, and obviously somebody who is very active, is 60 years old and suddenly can't run that much or is tired all the time because he or she's in atrial fibrillation, is very different from the 89-year-old patient who has had a bout of atrial fibrillation. We have to weigh the risks and benefits of our treatment approach to those respective patients.
For instance, we look at the chances that we can maintain atrial fibrillation long term. If they have significant comorbidities that are not controlled and a lot of risk factors that are not controlled, then maybe those patients are best managed with what we call rate control and anticoagulation or stroke prevention, so that we don't expose those patients unnecessarily to an invasive procedure. However, if the chances of restoring and maintaining a normal heart rhythm are good—which a lot of patients fit that profile, especially if they present relatively early in the disease process—then those patients may be better managed with a more aggressive approach, including catheter ablation of atrial fibrillation.
Our guidelines give us a lot of leeway, and invasive procedure to potentially cure atrial fibrillation has been more widely accepted. In the past we have said they have to have failed a trial of an anti-rhythmic drug. Nowadays, we sometimes give the patient the option to go straight to an ablation procedure, and if that's the patient's preference or if that's what they want, and it always involves a shared decision process. Really, I see my role as making sure a patient understands the different management strategies, and then we discuss what's the best treatment approach for that particular patient. Nothing's off the table. I think we have many tools to treat atrial fibrillation, and ablation is one of them, and I'd like to offer that to the most patients that I can.
In a situation where a patient is determined to benefit from a catheter-based ablation, how do you determine whether that patient should receive a cryoablation or a radiofrequency ablation?
Well, those are both good choices. We have a third one, which is laser ablation, and now we have a fourth one, which is what we call a non-thermal approach that does not involve heating or cooling or freezing the heart tissue. There are a variety of factors. For instance, cryoablation, where we freeze a little part of the heart that's critical to maintaining or initiating atrial fibrillation, requires a small balloon. And that technique or technology is very straightforward and very safe, but it can only isolate the pulmonary veins. So if that patient has any other arrhythmia that we know of, for instance, something called atrial flutter, then we would need to go to a second method or tool such as radiofrequency to ablate the atrial flutters. And we don't like to use and mix and match too many methods or tools in the same procedure, because that just complicates the procedure. So in that patient, I might just use radiofrequency from the get-go.
If it's a straightforward AFib ablation with no other arrhythmias involved or a first procedure, it really comes down to, I think, physician preference and what they're most comfortable with, which tool they're most comfortable with. All the standard tools, like radiofrequency, laser or cryo balloon, have been shown to be safe and effective and have a very comparable efficacy rate of around 80 percent for a single procedure.
And really it comes down to which tools the physician is most familiar with or comfortable with. As an experienced electrophysiologist, we can use most tools, and we just determine based on whether or not it's a straightforward AFib ablation, whether there are additional targets that we need to address during the procedure and what we're going to use. Also, if it's a second or third ablation, most electrophysiologists will go to radiofrequency ablation, which offers most flexibility in terms of determining where we're going, what we're doing and what our target is going to be.
Is there a limit on the number of ablations a patient could receive?
Technically, no. But each procedure is a separate procedure. Just like when you have cornea artery disease with multiple blockages in multiple arteries, some people will have had 10 stents or 12 stents placed. And over the course of 10 or 20 years, similar with atrial fibrillation, people can develop different mechanisms for the arrhythmia, and so they may require different ablations throughout the decades. I think there is certainly a limit in the sense of what makes sense for that particular patient. If I've tried two or three ablations and I see that there are no good targets left, then I think it's time to discuss different management strategies and say, "Well, maybe ablation is not for you, or the outcome of another ablation is unlikely to change the course of your disease," and look at alternatives.
One thing I was curious about was how you approach the use of ablation to treat patients who have asymptomatic Afib.
In the past, we only basically treated atrial fibrillation if it caused symptoms and if it caused any other comorbidities, like heart failure or something like that. With asymptomatic patients, it's much more difficult to assess the best treatment approach for that particular patient. Unfortunately, atrial fibrillation causes problems, whether it's symptomatic or not. So the dilemma is that, early on, patients may have no symptoms, but they still can develop heart failure down the road or have a higher incidence of stroke, even if they have no symptoms of the actual atrial fibrillation, they don't feel their heart being out of rhythm. But many of those patients go on after six months or a year or two years to be short of breath or more tired, or there's a higher risk of dementia or strokes.
There's a higher mortality long term if you have atrial fibrillation, at least if you have a significant burden of atrial fibrillation. I'm not talking about the patient who has one episode a year for an hour. I'm talking about the patient who has quite a bit of it. So unfortunately, if we wait until these patients become symptomatic, then the success of, for instance, an ablation procedure is much lower after a certain time. We might miss that golden hour of treatment option or cure option in this patient. If I see a patient who has no symptoms, I have to discuss with him that even though you don't feel it now, you might feel it or it might cause problems in two, three or four years down the road. But at that point it's going to be too late to get you back in a normal rhythm and to keep you in a normal rhythm.
Outside of ablation, can we talk about some other non-pharmacologic avenues for stroke prevention with left atrial appendage occlusion devices such as the WATCHMAN device?
First of all, I want to step back one minute and say, we are so fortunate for the past 10 years that we have had other blood thinners than the good old Warfarin or Coumadin that we used for many, many, many decades. And that was really difficult to manage in many patients, because it interfered with their diet, it required frequent blood tests. And even though it's been shown to be very effective in stroke prevention, we always had a hard time getting more than 60 percent of patients properly anticoagulated with Warfarin. So, we've got many other new blood thinners on the market, which are pills that do not require constant monitoring and do not interfere with your diet. We have a lot more options, and they're probably also safer than some of the older blood thinners.
Now, in addition to that, there is what we call a non-pharmacologic approach to stroke prevention. We do know that most strokes come from the left atrial appendage, a little structure in the left upper chamber of the heart where blood tends to pull and clot and can fly off into the circulation into the brain. So we found out that if we somehow obliterate that little left atrial appendage, then we can prevent most strokes almost as, or as effectively as using blood thinners. And so there are a variety of tools to do that.
There are surgical approaches. There is something where you ligate the left atrial appendage with the Lariat approach, which is a minimally invasive procedure. And then there little gadgets that we can place into that left atrial appendage. The most common ones being the WATCHMAN device, but also the amulet device, and other companies are coming with similar approaches. The idea being that we're going to plug the entrance to that appendage, and within a few weeks they get sealed off by building a membrane on top of it. And so, that procedure is pretty straightforward and takes about half an hour to an hour, then it's done. Again, through a catheter-based approach. And in patients who cannot take blood thinners long-term, it's a great alternative to prevent strokes.
And are there any other newer non-pharmacologic treatment strategies that are also being researched at the current time?
Yes. And at RUSH, we are about to embark on a trial, I think in the REACT-AF Trial. Now with the occurrence of smartwatches and other monitoring devices, the idea is that maybe some of the low-risk patients do not need to take blood thinners long-term, and still have a low risk of stroke, and just take it only on an as-needed basis. So how that would work is that if a patient, for instance, wears a smartwatch that can detect atrial fibrillation, they would alert us or let us know if they have an episode, for instance, longer than an hour. And then they would take the blood thinner only for 30 days after such an episode.
And there's some preliminary data that suggests that that's a safe approach, and that we can reduce the time the patients is taking blood thinners by over 90 percent, so that they're basically only taking blood thinners for short periods of time if they have had a recurrence. Again, these are newer strategies. The studies will tell us on the largest scale whether that will work and whether that's safe to do, but it's an exciting new era of modern medicine and modern monitoring technology that can hopefully prevent complications due to blood thinners.
Do you think there's overall acceptance within the electrophysiology community about the benefits of using a smartwatch or a smart device for patients to monitor their AFib symptoms, or do you think there are diverging opinions within the community about them?
I'm sure there's a mix there. Most electrophysiologists I talk to are excited about this approach. Obviously, we are relying on patient compliance to wear the monitor, to notify us if they have a prolonged episode, and then go along with a treatment plan. But patient compliance is always an issue, no matter how you treat them.
I think most electrophysiologists are excited about the opportunities that these smartwatches, that are widely available, offer us in terms of managing these patients long-term. Some of them have been FDA-approved to detect atrial fibrillation. They're quite sensitive and reliable, and I do believe that they're going to change how we practice in many ways, both to document the effectiveness of whatever treatment approach we use, and to prevent strokes down the road. But again, we're lacking large scale trials, but the preliminary data are promising.
I've got one last question for you today, which is about Pulsed Field Ablation or PFA technology. Can you talk about how soon they'll be able to be used in practice at RUSH, and what the potential benefits for patients will be?
We are getting ready to use it here at RUSH. It's been pretty much experimental and part of trials only. Pulsed field technology is very exciting. It is what we call a non-thermal ablation method or tool. Instead of destroying tissue with heating it or freezing it and then having an inflammation, this causes what we call electroporation in a very circumscribed region, and can very safely create very effective ablation lesions that are transmural, meaning that they affect the whole thickness of the heart if needed, which is key to long-term success, at least in AFib ablation.
It's an exciting new technology. All the preliminary data that we have seen show that it is very safe to use. It can potentially avoid collateral damage to other surrounding tissues. When we do ablation, that's one thing always we're concerned about. If you heat the tissue, there's always some heat that transmits to the adjacent tissue and could potentially cause problems.
With this form of non-thermal energy, we can destroy tissue and create a scar that's well-defined and does not affect any surrounding tissues, without causing any collateral damage or potential collateral damage. There are still a few things that we are trying to figure out, what's the best protocol technique. There are a lot of physical or physics variable that can be altered to use this effectively. Catheters are in development to effectively deliver this new form of energy.
But generally, the electrophysiology community is very excited about having a new, very safe treatment method for ablations. In terms of long-term effectiveness, the jury's still out. I think it's going to be at least as effective as all the other tools that we have right now. It's potentially safer, and that's already half the game. So we're excited about it.
How close are we to implementing that in actual care?
We are hopefully going to start using PFA in the next few months at RUSH. As I said, it's still usually part of a protocol until we gather more data, so it's happening as we speak.
