Hybrid Treatment Approaches for Atrial Fibrillation

Additional Info

• Audio File:uf_health_shands/ufhs034.mp3
• Doctors:Miles, William;Beaver, Thomas
• Featured Speaker:William Miles, MD, FACC | Thomas Beaver, MD, M.P.H.
• Guest Bio:Dr. William Miles is Professor of Medicine and Silverstein Chair for Cardiovascular Education. He joined the faculty at the University of Florida in 2005. Prior to his current appointment, he was on the faculty at Indiana University from 1983-1998 where he was Professor of Medicine and Director of the Electrophysiology Laboratory. 
  
  Learn more about William Miles, MD, FACC 
  
  Dr. Thomas Beaver is The Grant and Shirle Herron Chair and Professor and Chief of The Division of Thoracic and Cardiovascular Surgery at The University of Florida College of Medicine. 
  
  Learn more about Thomas Beaver, MD, M.P.H.
• Transcription:The University of Florida College of Medicine is accredited by the Accreditation Council for Continuing Medical education, ACCME, to provide continuing medical education for physicians. The University of Florida College of Medicine designates this enduring material for a maximum of 0.25 AMA PRA Category 1 Credit. Physicians should claim only the credit commensurate with the extent of their participation in this activity.
  
  Melanie:  Welcome to UF Health MedEd Cast with UF Health Shands Hospital. I'm Melanie Cole, and I invite you to listen as we examine hybrid treatment approaches for atrial fibrillation. Joining me is Dr. Thomas Beaver, he's a professor and Chief in the Division of Cardiovascular Surgery at UF Health Shands Hospital; and Dr. William Miles, he's a professor in the Division of Cardiology at UF Health Shands Hospital.
  
  Gentlemen, it's a pleasure to have you join us today. Dr. Miles, I'd like to start with you. Tell us what you're seeing in the trends for atrial fibrillation. And while you're doing that, please review the types of AFib, including paroxysmal and persistent, and which ones you're seeing more commonly.
  
  Dr. William Miles: Well, we feel like we are seeing a lot more atrial fibrillation recently and we think it's probably because the population is aging. There's a fair amount of chronic illnesses like hypertension and diabetes in the population, which predispose to atrial fibrillation, being overweight predisposes patients to atrial fibrillation. And we now know that sleep apnea and other sleep disorders make patients are very prone to have atrial fibrillation to the point that almost every patient that comes in with atrial fibrillation we now screen for sleep apnea and send a lot of them for sleep evaluation.
  
  Patients can have either persistent or paroxysmal forms of atrial fibrillation. We think the paroxysmal form is sort of in most patients an earlier iteration than the persistent forms. The paroxysmal forms are a little bit easier to treat. The paroxysmal atrial fib is atrial fib that starts and stops spontaneously. The patient may have one or two episodes a week or a month or may have many episodes in a day, but each episode stops on its own and thought to be maybe earlier stages of the progressive progress that atrial fib goes through.
  
  Persistent atrial fib is atrial fibrillation that doesn't stop on its own. That can go on for hours and days until we give a drug or we cardiovert or we do some type of ablation. For the paroxysmal forms, we often start with drug therapy or ablation therapy, catheter-based ablation therapy as the first option and we leave more complicated things for patients who don't respond.
  
  The really interesting area these days is persistent atrial fibrillation where the therapies are much more difficult and so procedures that we're interested in that combine catheter-based with some minimally invasive surgical-based techniques may be advantageous in those particular types of patients.
  
  Melanie: Thank you so much Dr. Miles, for that answer. So Dr. Beaver, we're going to get into this hybrid treatment options and approaches, but before we do, is there anything exciting in diagnosis for AFib? Tell us what you're doing.
  
  Well,
  
  Dr. Thomas Beaver: I think Bill as a cardiologist sees more of the patients on the frontline and as a surgeon, I work closely with him to treat these more difficult patients. But Bill can comment more, but I think people now have iPhones and iWatches and electronics and probably are bringing their AFib to him in the office. Bill, have you been seeing that?
  
  Dr. William Miles: Yeah, we certainly have, and it's actually been very useful. You know, pulse monitors when people would bring in pulse tracings, they are very inaccurate and they're not really particularly helpful in most cases. But the new apps that have an actual electrocardiographic tracing and they can be very high-quality EKG tracings, they are very useful. And you can usually look at those and tell whether is this atrial fibrillation? Sometimes it's artifact that has to be distinguished from atrial fib. Is it atrial flutter? Is it PVCs or just PACs, premature atrial or ventricular contractions?
  
  So we think these patient-based apps are very useful. They don't completely substitute for 24-hour monitors or two-week or a month-long monitors, but they're very useful to help guide us in diagnosis and therapy. It may help us tell whether someone has paroxymal atrial fib or persistent atrial fib, for example.
  
  Melanie: Well then, Dr. Beaver, as oral anticoagulants are really an important therapy, we know that, but they come with limitations and many patients need an alternative. Tell us about some of these treatment approaches and what you're doing at UF Health Shands Hospital. Speak about the hybrid approaches that we've briefly mentioned.
  
  Dr. Thomas Beaver: Well, I think as Bill can comment further when you have atrial fibrillation, there's really two concerns. So one is the concern about the actual heart rhythm affecting the blood pressure and the way people feel. And then there's also the huge component of stroke risk. And that is why patients, of course, are on the blood thinners to prevent strokes, from forming an atrial appendage predominant site where strokes would form.
  
  For over 10 years now, we've been doing a clip that we can put minimally invasive via thoracoscopic between the ribs and that clip essentially isolates out the atrial appendage, and the procedure takes about 30 minutes. And patients that are good candidates for this-- I actually saw a patient yesterday, who they're tried on trials of some of the novel oral anticoagulants or warfarin itself, the traditional anticoagulant, and then they don't tolerate them. For example, some people have stomach bleeding or some people have hematuria or most commonly radiation proctitis from history of maybe radiation to their prostate. So these patients are ideal candidates for these new therapies. There's also the endocardial approach, and they can be put in the cath lab, which is the Watchman device. But I've seen a few patients. In fact, one earlier this year with an atrial appendage that is actually too large for the Watchman, and they're referred for this clip, which is really tolerated very well by patients.
  
  Dr. William Miles: if I can jump in the other patient that I think the left atrial minimally invasive clip is an advantage for is a patient who has an absolute contraindication to anticoagulation. Because to clip the appendage with minimally invasive surgery, the patient doesn't have to be anti-coagulated at all either before or after the procedure. Whereas if you implant a left atrial appendage occlusion device, there needs to be a period of full anticoagulation currently usually about 45 days after implantation of the device.
  
  So if the contraindication to anticoagulation is just relative you can get away with that. But if they have a very serious problem with any anticoagulation, a left atrial clip might be the better therapy for that particular patient. So we try to customize what type of procedure we do to each individual patient's needs.
  
  Melanie: And Dr. Miles, speak a little bit more, expand on the post-procedure drug regimen for us. What happens after one of these procedures or the hybrid procedure or the Watchman, as you mentioned, any of these, are they still using those anticoagulants? What are they doing? What are you doing for them now?
  
  Dr. William Miles: Yeah. So we think that the procedures for atrial fibrillation are not perfect because atrial fibrillation is a progressive process and also a multicentric process that can come from almost anywhere in the left or the right atrium. So once you get rid of atrial fibrillation or minimize atrial fibrillation with any type of ablation procedure currently, we think most of those patients, if they have a high stroke risk score or to begin with, anticoagulation needs to be continued.
  
  So again, one of the advantages of a hybrid procedure that Dr. Beaver does with thoracoscopy, minimally invasive thoracoscopy, is that he can take the left atrial appendage. And once that's done, once the left atrial appendage is clipped, we think that the risk of stroke, of a clot originating from the left atrial appendage is minimized to a point that patient may do okay without anticoagulation.
  
  In general, though, if a patient has a catheter-based atrial fibrillation procedure or drug therapy for atrial fibrillation without occlusion or clipping of the left atrial appendage, if they have a high stroke risk to begin with, they still need anticoagulation afterward.
  
  So again, the two major things that we have to address in every patient with atrial fib is it causing symptoms or is it causing left ventricular dysfunction, number one? And number two, what have we done about the stroke risk?
  
  Dr. Thomas Beaver: I think I might just jump in here, Bill, and just to highlight what the new approaches are. So paroxysmal, as you know, Bill, you've been doing it for years, the catheter approach is actually very successful, especially with the new cryoballoon, but really where I think you find it challenging is the patients that have the persistent AFib for several years, perhaps they've had a catheter ablation in the past and that they still have AFib that's symptomatic for them.
  
  And that's where these newer hybrid procedures, actually they've been around for some time, but I think what's generated interest is the American Heart Association, the clinical trial results from the Convergent procedure, which is one of the two approaches was presented and that clinical trial showed there was a very significant benefit combining a surgical pericardial window, so to speak, where a catheter could be used to ablate the posterior left atrium in tandem with your catheter isolation of the pulmonary veins. And that was proven to be about 70% effective in restoring patients to normal sinus rhythm.
  
  And by the way, we can also put a clip on in that patient if we do that in the operating room to eliminate the stroke risk from the appendage. So that's a very new procedure that we've been doing over the last couple of years here at UF Health. But this is in addition to, as you mentioned earlier, the thoracoscopic approach, which you've also been doing probably over 10 years, which is also in a separate clinical trial, by the way, here at UF Health. It's called the DEEP trial, dual epicardial and endocardial procedure. A clinical trial, which again combines the thoracoscopic approach where we can isolate the pulmonary veins, put a clip on the appendage and then actually create additional ablation lines in the posterior left atrium, which appears to be real driver of atrial fibrillation in the patients with persistent AFib.
  
  And then Dr. Miles can come in and then map those patients. And we have now enrolled three patients in that clinical trial and they're all in sinus rhythm. So we're very excited about the promise of that clinical trial, which is still ongoing. Maybe, Bill, you could comment on the mapping that goes along with those patients, because we've also had some pretty nice maps patients.
  
  Dr. William Miles: Yeah. The principle here is that the cornerstone of atrial fibrillation ablation is isolation of the four pulmonary veins where most atrial fibrillation originates. But as atrial fibrillation progresses from the paroxysmal to the persistent forms, more and more the atrial fibrillation drivers and rotors, the things that generate the atrial fib are located on the posterior left atrial wall. We can address those with catheter ablation, but I'm very jumpy about it because right behind the posterior wall is the esophagus and a very, very life-threatening complication, although rare, can occur if you try to do radiofrequency ablation in those areas.
  
  There are a lot of physicians who do that and they dance around the esophagus and try to avoid it. But I think that a safer way of approaching the posterior wall of the left atrium in people with persistent atrial fib is to do this pericardial access called the Convergent procedure and the maps that we get show very extensive and, for us, very beautiful voltage maps of ablation of the posterior wall by pericardial scope access, the Convergent procedure, with very little worry at least on my part. I don't know how much you worry about it, Tom, but very little worry on my part about damaging the esophagus. So we know where everything is. We control the direction of the heat. We get good posterior wall ablations epicardially and endocardially without risking esophageal injury.
  
  Dr. Thomas Beaver: Well, I think the key is when we have that at epicardial approach, Bill, we're able to direct the ablation catheter towards the left atrium, which is in the 180 degrees opposite the esophagus and also similarly in the thoracoscopic approach. So rather than if you would will in the endocardial procedure where you're actually directing towards the esophagus, we're going the other way. So I think we feel pretty safe.
  
  Melanie: Absolutely fascinating, doctors. I'd like to give you each an opportunity for a final thought. And Dr. Beaver, why don't you start in what you find most exciting for the future of stroke reduction in AFib patients, any procedures you see upcoming, equipment, you know, advances in diagnostic radiology, anything you'd like to discuss as your final thoughts?
  
  Dr. Thomas Beaver: Well, I think what we're excited about and we know that patients that have AFib and actually that have already had a stroke are at significantly higher risk for a repeat stroke. And we've already proven in a small clinical trial that was funded by the NIH here at our center, that we can essentially reduce that risk with these procedures, by putting a clip on.
  
  We followed patients out one year with a follow-up MRI and we had 12 patients in the surgical arm, and none of them had strokes whereas a couple in the medical arm did in fact have a repeat stroke. So these procedures are not only for the general population, but particularly for patients that have had a stroke in the past with AFib. It's a wonderful procedure in my mind. We'll need more trials and more clinical trials, which are ongoing. In particular, I mentioned the deep trial, but I think it's an exciting time and at UF Health. I've appreciated working with Bill over the last 10 years, and we have significant amount of experience taking care of these patients.
  
  Dr. William Miles: Well, I can just say two things very quickly. One, there are new energies other than radiofrequency energy that are being developed, that probably may be able to limit collateral damage such as the esophageal or phrenic damage. One of those is called electroporation, and I think that that's showing some promise. And the other thing is sort of mundane, but the new anticoagulants that are substituting now for warfarin are so much easier for patients to use no monitoring. They're safer from an intracerebral bleeds standpoint. I think that's really a large step forward on the pharmacologic therapy for the prevention of stroke. So those are two things I could mention that I think are steps forward and exciting.
  
  Melanie: Thank you, gentlemen, so much for such an interesting discussion about atrial fibrillation and hybrid treatment approaches to refer your patient, please visit UFHealth.org/heart for more information. Or to learn about other healthcare topics at UF Health Shands Hospital, you can visit UFHealth.org/medmatters to get connected with one of our providers.
  
  And that concludes today's episode of UF Health MedEd cast with UF Health Shands Hospital. Please remember to subscribe, rate and review this podcast and all the other UF Health Shands Hospital podcasts. I'm Melanie Cole.
  
  
• Hosts:Melanie Cole, MS
• Post Test URL:https://cme.ufl.edu/mededcast/