Transcript
Matthew DeVane, DO FAAC: [00:00:08] Hi, I'm Doctor Matt DeVane.
Carolyn Lacey, MD FAAC: [00:00:09] And I'm Doctor Carolyn Lacey. We are cardiologists at John Muir Health and this is our podcast, Living Heart Smart.
Matthew DeVane, DO FAAC: [00:00:16] Our physician partners and colleagues are going to help guide you through many different and important cardiovascular topics to help keep your heart happy and healthy.
Carolyn Lacey, MD FAAC: [00:00:24] Thank you for listening and we hope you enjoy our show. Hi everybody. Thanks for coming back to another episode of Living Heart Smart. We're continuing our atrial fibrillation journey, and I think this episode is really one of our most important episodes. It's going to be one of our harder episodes that we've had, that we've had so far. We're talking about atrial fibrillation, but we're also talking about stroke. And one of the biggest risks with atrial fibrillation is stroke. And I think that all of us Matt and I and we're here again with Doctor Andy, Ben talking about stroke and how we prevent stroke. But we've we feel so strongly about this because we've seen the impact. We see patients in the hospital that have had atrial fibrillation and stroke related to atrial fibrillation, and this can be life changing. This is life changing and it can be life ending for a number of people. So we really want to talk strongly about this. And even though it's a really rough thing to talk about, we're here again with Doctor Andy Ben. And before we get into our deep, deep discussion. Doctor Ben, one thing that we've learned about you is that there's more to you than being a cardiologist, and I've just started to learn about your favorite t shirts and having clothes related to TV shows. Can you tell me your top three?
Andrew Benn, MD: [00:02:03] You know, there's a lot of good in 2020 for one of our great cultural advances is that you can buy swag from fictitious places that are on television.
Carolyn Lacey, MD FAAC: [00:02:14] Lots of swag.
Andrew Benn, MD: [00:02:15] So my favorite t shirt, of course, is my Pollos Hermanos t shirt from Breaking Bad. The chicken stores that Gus ran. Yes. As a front for his drug operations. I'm a big fan of the big Cat Lodge t shirt from Ozark. That was the lodge that Marty buys so that he can launder money through it. And of course, tonight I'm wearing my Rose apothecary shirt from Schitt's Creek, which will always have a special bond for me, because when we were all stuck at home during Covid and our kids had to move in with us, um, and then ultimately our granddaughter, they really said, you got to watch Schitt's Creek. So it always it was. It's such a good show and I encourage all listeners to watch it. Um, at the same time, because it was such a hard, emotional time for us all, culturally. Yeah, it creates that greater bond. So I encourage all of you to buy those acts, capital t shirts from billions, uh, or Waystar.
Carolyn Lacey, MD FAAC: [00:03:07] Or wherever.
Andrew Benn, MD: [00:03:08] From succession.
All: [00:03:11] Oh, good. That's great.
Matthew DeVane, DO FAAC: [00:03:12] Well, thank you for sharing that. We're going to, uh, hopefully dive into some good stuff about stroke prevention today and how we can all move forward with that. Doctor Ben, thanks for being back today. So what is a stroke and how should our patients be thinking about it?
Andrew Benn, MD: [00:03:29] Stroke. As you said, Matt, is a term that is often thrown around by thoughtful people, but it's thrown around as a generality. Let's look back in history to understand what it means. Strokes were named by the English in the 19th century because everything changed with one stroke of the clock. That's how they were originally named.
Carolyn Lacey, MD FAAC: [00:03:49] I love that, I love that.
Matthew DeVane, DO FAAC: [00:03:52] I never even heard that.
Carolyn Lacey, MD FAAC: [00:03:53] I've never heard that, I love that.
Andrew Benn, MD: [00:03:55] What changes with one stroke of the clock is the patient's neurologic picture. A stroke is a brain event. With that one stroke, they may lose function of motor where they can't move one side of their body, or speech, or both, or vision in one eye or general cognition. When you think about strokes, when you hear about anyone you know having a stroke. Strokes really break out into three types. 10% of strokes are hemorrhagic where there's been a primary bleed into the brain. That's most commonly associated with hypertension, especially uncontrolled hypertension. Back to the important control of risk factors. And we talked about how benefits compound when you're treating your blood pressure. One of the many things you reduce is that that's 10% of strokes. The other 90% of strokes are not about immediate bleeding. They're about the clogging of the blood supply to a particular part of the brain. In 70% of strokes. So seven of the remaining 70 of the remaining 90, it's due to atherosclerosis, artery clogging, cholesterol buildup. Think of that kind of stroke as a heart attack of the brain. It's an artery clogging event. But instead of affecting a heart artery where we call events heart attack, we it It happens in the brain where we call events stroke. Many stroke researchers about 20 years ago were on a kind of a big kick. They felt strokes were underfunded, and they actually discussed changing the name of stroke to brain attack to point out its equal importance.
Andrew Benn, MD: [00:05:32] And it is for men over 50 and women over 60. Still the number two killer of people in the United States. The last 20% of strokes are not caused by an event right at the site of the artery closure, like a cholesterol plaque, it's caused by what's called an embolus. An embolus means a piece of something formed upstream and washed downstream to caulk the artery. And that's it's a piece of debris cutting off blood flow. The vast majority of that 20% are due to atrial fibrillation and clots forming an atrial fibrillation that then break loose and travel to the brain. When you look at atrial fibrillation, it functionally accounts for 20% of all strokes that someone experiences. The atrial fibrillation stroke is definitively based on the large volume of them we have. Sadly larger. It will damage more brain than other kinds of stroke. It is more likely to be fatal than other kinds of stroke, and if you survive the atrial fibrillation stroke, you are significantly less likely to be able to live independently. So the damage done would be greater. When you look at atrial fib and the clots that form flying out to cause events. What we've learned from some of the trials of the new blood thinners consistently is that when a clot leaves your heart, we'll talk about how that formed in just a moment.
Andrew Benn, MD: [00:07:04] When a clot leaves your heart, the odds that it will travel to the brain are nine out of ten. So in all the trials of the new blood thinners that were done about 15 years ago, now 90% of these events that we call embolus were to the brain and 10% were to the rest of the body. Why would that be if anatomically, you could look out the valve, the aortic valve that lets blood out of the heart, you'd be looking right up at the carotid arteries. So it's simply a mechanical problem. The piece of clot flies out of the brain. It fails to make a turn. It just shoots straight up and causes the stroke. Now, why does atrial fibrillation lead to stroke? Let's go back to the first podcast we did where we talked about the model of the heart that we drew. We drew the Valentine. We drew the two bumps coming into the triangles. And we said those two bumps were the atrium, the left atrium, and the right atrium. If we saw the left atrium alone, the left atrium looks like a ball, but it's a ball that has attached to it on the inside. What looks like one of those windsocks that you see at the airport, the kind that's floppy.
Carolyn Lacey, MD FAAC: [00:08:16] That's exactly how I describe it too, as a windsock.
All: [00:08:19] Yeah.
Andrew Benn, MD: [00:08:20] You know, I was Air Force, um. That windsock is called the left atrial appendage. And we don't understand medically why we all have left atrial appendages. But we've got them. And like a little cul de sac off this ball flow in that little cul de sac is more static. So when the atria, when the left atrium and the right atrium stop squeezing, blood is generally more stagnant within them, especially in that little cul de sac where flow wasn't great to begin with. And it's well understood that over 90% of the clots that form an atrial fibrillation form in that slow flow left atrial appendage. When you ask, based on echo studies, what's the size of clots that form in the left atrial appendage? The average size on esophagus echo is two millimeters. When you look at anatomic postmortem studies, what's the average size of your left middle cerebral artery? The diameter is two millimeters. So the reason that atrial fib strokes are likely larger than other strokes is simply the size of the clot that forms matches a very large artery in your brain. In the late 80s, from about 88 to 91. Multiple multiple large population studies, including Framingham, came out and they all came out with the same number. And if you only had 30s to listen to this podcast, that would give you one number and is the most important number in atrial fibrillation, and that number is five.
Andrew Benn, MD: [00:10:00] All other things being equal between two people, the risk of stroke in the atrial fibrillation patient is five times that of the general population. And that's been validated over and over and over in very large populations. And if you stop listening now and you only remember that you've learned something very important because it shapes what we do. But right around the time those population studies were coming out, work was being done at Oxford by a guy named Greg Lipp. And Greg Lipp said, yes, there is a five fold risk of stroke as it pertains to the atrial fibrillation population, but it appears also from population studies that that risk is not distributed evenly. The different people with atrial fibrillation carry different risks of stroke. So he invents a risk score that had a total of six points. And he created an acronym so that all US practitioners who are so busy could remember it and was called chads. And chads had a maximum score of six, the highest risk and a minimum score of zero. And then after he validated that against large populations and showed that it was very useful and practical, people came along and worked with him and suggested refinements. And the score we use now is called Chadsvasc. So it incorporates some other factors that weren't in chads.
Andrew Benn, MD: [00:11:21] But it is. It is the score that your practitioner should and will use to determine whether you have a need for blood thinners. Um, and then we'll talk about the selection of blood thinners a little bit after that. So as a consumer of atrial fib, if it's about you or someone you care about, you might say, what is their chadsvasc score? The elements of the chadsvasc are the same things we talked about as being associated with atrial fib. Congestive heart failure. That's the first C hypertension age over 75, because your stroke risk in atrial fib goes up as your age goes up. D for diabetes, S for previous stroke or Tia V for serious vascular disease like coronary artery disease or peripheral artery disease. Um the A for age 65 to 74 gets you lesser points, but still gets you points and the s for sex because women, uh, at every Chad score were found to have 40% more stroke than men. So it got incorporated into chadsvasc. You don't have to memorize that score, but if you're dialoguing with a practitioner, say, what's my chadsvasc score? The current feeling is, for men, a score of two and above mandates anticoagulation unless there's a strong medical reason not to do it. Three for women, which in essence accounts for that one point due to being a woman in the Chadsvasc score.
Andrew Benn, MD: [00:12:47] That's the standard of care right now for people who are below those Chad scores. So a man with a score of zero, or one woman with a score of 0 to 2, uh, there is consideration of no therapy. There's consideration of aspirin or other antiplatelet drugs. This would probably be a good two minute sidebar to say, what about atrial flutter? Uh, when I was in medical school, we thought atrial flutter was the sister of atrial fibrillation, that they were hand in glove. They were both electrical short circuits. They're both arrhythmias. People who have one not uncommonly have the other as well. But some people just have atrial flutter. Atrial flutter is associated with 2 to 3 times the stroke risk of the general population, and still felt to require anticoagulation, still using the Chadsvasc score. It is a different rhythm with a different location, and it's very, very curable with ablation. But we won't touch on it any further on this podcast. So as we look at how do we reduce this stroke risk back down towards the risk of the general population? For the large majority of patients who have atrial fibrillation, it's going to be oral anticoagulants. So most patients with atrial fibrillation should expect that the standard of care will be to put them on a blood thinner.
Andrew Benn, MD: [00:14:09] Now we know blood thinners carry with them an increased risk of bleeding for some patients, an unacceptably high risk. Maybe they've got a problem with some form of bleeding that we can't get under control. And for those patients, there are other mechanical options, like the watchman. That's going to be discussed in a later episode of this podcast. And worth certainly bearing in mind for patients who are on a blood thinner, how do we modulate that bleeding risk? How do we mitigate it so we have the least chance to have the bleeding that's associated with all blood thinners? The answer is one. We try to avoid supplements that are known to potentially thin the blood further, such as fish oil. We know we avoid drugs that affect the platelets when you think about the clotting system. Clotting system has two sides to it in the body. It has cells that participate in the clot. We call those platelets and it has proteins. So when you take something like an aspirin or you take Plavix, if that's a drug you're familiar with, you're interfering with the platelets. When you're taking a blood thinner. And what the word blood thinner words blood thinner imply is that you're interfering with the proteins. And we don't like to mess with both sides of that equation at once.
Andrew Benn, MD: [00:15:25] So no aspirin, no ibuprofen, no naprosyn, which you might know on the market as Aleve. All the non-steroidal anti-inflammatory drugs are out, though. Tylenol is okay when we look at the blood thinners In 1952, the Wisconsin Agricultural Research Foundation in Madison, Wisconsin, a great town. Anchorage, all of you to visit at least once in your life in Mad City. They noticed in the late 40s that there were a group of cows that ate some spoiled clover and bled to death. They looked into it and it turned out that spoiled clover produces a molecule called warfarin. In 1952, warfarin is marketed by the Wisconsin Agricultural Research Foundation. The first four letters of warfarin as a rat poison. It is then released two years later as the only oral blood thinner we had in the United States. There were other variants of it available in other countries, and it was the only oral blood thinner we had. Between 1954 and late 2010, when a new group of blood thinners begins to come, out of which there are now four available in the United States. We originally called those new blood thinners noacs because they were novel. The N was for novel. Now they're just called Doacs because they're direct oral anticoagulants. They have the advantage of being as good or better, depending on which one we want to discuss at preventing stroke is warfarin.
Andrew Benn, MD: [00:17:06] They don't require the daily blood tests of warfare or the weekly blood tests of warfarin. They don't have the dietary restrictions of warfarin, which is a direct competitor of vitamin K, which is in a lot of the green leafy vegetables and some other foods we eat. They don't have the large amount of drug interactions that warfarin had, but let's acknowledge and stop and say warfarin did a great job when it was the only drug we had at preventing stroke. I think in cardiology, we've come to the conclusion that the newer, effective new therapies are more effective in that they don't require the blood testing, they reduce stroke as well or better. Many of them have lower bleeding rates and they don't have the drug interactions. Um, they're reversible more quickly than warfarin because there are antidotes for those blood thinners now available widely. And so that's why you see that the guidelines for quite a number of years now, including 2024, point us toward using them preferentially to warfarin, except in certain very special states like a mechanical heart valve or Antiphospholipid antibody syndrome. Certain other conditions where warfarin still has, uh, failed to have a strong role. The new blood thinners offer several other advantages as well. The procedures that patients undergo often require that they hold blood thinners.
Matthew DeVane, DO FAAC: [00:18:30] Yeah, we get this question a lot. How do I get a procedure done?
Andrew Benn, MD: [00:18:35] Now? You simply stop the new blood thinners and you resume them as quickly after the procedure as the procedure operator felt is safe if there's bleeding. As I touched on it a minute ago, all of the major new blood thinners, if either after a procedure or in general bleeding were to occur, all All four of the newer blood thinners are reversible within minutes in an emergency room.
Carolyn Lacey, MD FAAC: [00:18:59] This was such a great explanation. Again, I'm going to steal multiple things that you've said, and I'm going to tell my patient. I'm going to pretend that it's my own when I'm talking to my patients. But let's move into some of the questions that we get asked all the time. And one thing that I thought that you explained really well is with the chads score and the chads vasc score, what patients asked me, I'm not in AFib right now. Do I need to be on a blood thinner? How do you answer that question to your patients?
Andrew Benn, MD: [00:19:30] Uh, if I'm in a quick hurry, I guess the answer is yes. You do. Quit asking me questions. But if I have more time. If you have more time.
All: [00:19:36] And being.
Andrew Benn, MD: [00:19:36] Nice. Doctor Ben, that day I would say to him. Yes, remember that even the patient who's sure they're feeling all their atrial fib is feeling 15% of their atrial fib, and that atrial fib is a chronic illness, as Matt touched on so well quite a while ago in this series. And that if you're someone who's had infrequent spells of atrial fib as you age and as time goes by, for the most part your spells will be longer, they'll be more frequent and eventually maybe even persistent. Whether you feel them or whether you don't, because the presence or absence of symptoms has no impact on your stroke risk at all. So once you've been identified as someone with enough atrial fibrillation to warrant anticoagulation, really, that's anticoagulation for life. Even if we do a procedure like ablation to try to take away your atrial fib, we know it's only in the best of cases, 75 to 80% successful. So you still carry that risk of atrial fibrillation. Now how much atrial fibrillation a patient has to have to warrant anticoagulation has been a bit of a moving target. Early studies showed that you had to have atrial fibrillation spells lasting hours to really declare yourself as having that five x risk.
Andrew Benn, MD: [00:21:01] That pendulum swung all the way back, maybe on what I would call a soft medical literature. I don't think it was the most well crafted down to six minutes. Uh, then the pendulum swung back the other way and landed for quite a while at that 2 to 3 hour mark. Now it seems to be moving back again. A fourth move of the pendulum back towards shorter spells of atrial fibrillation may well be associated for my own patients. I say if at any point, whether on a pacemaker, check, an Apple Watch, a patch monitor like we discussed, your demonstrating atrial fibrillation spells that last a good part of an hour. We know you're going to be prone to spells that could be longer. And that's where I myself. Art of medicine. Not hard science to back me up, but the way I put all that literature together is if you're having spells that last most of an hour, you easily could do longer and you need to be on anticoagulation as if someone who were in atrial fibrillation for much longer blocks of time.
Carolyn Lacey, MD FAAC: [00:22:04] Andy, I like how you really talked about the pendulum, about how much AFib is too much AFib. And, and I, I just want our listeners to know that this is one of those questions that we don't know the answer to. And I myself, I like to listen to a number of cardiology podcasts. And there have been that are meant for cardiologists. And this particular question has come up again and again, actually recently in how you say it's still the art of medicine. You know, we we don't know how much is too much. But I think what we're starting to find right now is that pendulum as it's swinging back, it really is. If you're having the better part of an hour or so in atrial fibrillation, that's too much. And that puts you at higher risk for stroke.
Andrew Benn, MD: [00:22:49] I think it does. I think what's helping us is we're getting more and more tools, Things we've talked about over these podcasts to look at the AFib burden, the length of AFib, and we're able to get more detailed information. So I think we're going to fine tune that number. And maybe most importantly, if you're listening to this and you're a patient who's had some AFib, the reason to check in regularly with your cardiologist is a lot of these questions in atrial fib are still not completely defined. And though you haven't changed, the body of knowledge that we're going to bring to atrial fibrillation is going to change even while you're doing great. So your care, I hope, if you're listening to this is state of the art right now, but that's going to be a moving target as the body of information changes. Uh, you know, at our local hospital, we're involved in a trial with a new category of blood thinners that looks exceedingly promising. So the best blood thinners of 2024 are felt to be those for newer blood thinners that we discussed that came out beginning in 2010. But that may not be the truth of 2026. And that's the reason to check in with your cardiologist regularly. Even if you feel like, hey, I'm ACS, I don't I don't need any changes.
Carolyn Lacey, MD FAAC: [00:24:03] You know, I think you you also just led into another really good question about how that I get asked a lot, especially for patients who've been on warfarin for a long time, and they they feel very secure with having the INR measurement. I know that my measurement on the warfarin, I know I'm in the range, and they sometimes feel very nervous about switching to some of these newer drugs.
All: [00:24:30] I feel exposed, right? They feel.
Carolyn Lacey, MD FAAC: [00:24:31] Exposed. How do you know it works? How do you how do you tell patients when you're transitioning them? Or as you deal with this question when you're talking about anticoagulation with your patients?
Andrew Benn, MD: [00:24:42] We know from very, very large studies, think tens of thousands of people. Is that all four.
Speaker5: [00:24:50] Of.
Andrew Benn, MD: [00:24:50] The alternative blood thinners to warfarin can say unequivocally that without a blood test to check how thin my blood is, I can say to you, you're bleeding. Risk is either no worse than warfarin or distinctly better. And even with the blood test to back it up, warfarin could not do a better job at preventing.
Andrew Benn, MD: [00:25:13] Bleeding.
Andrew Benn, MD: [00:25:14] Than the newer drugs, typically a little bit worse. So what we know is that time proven safety, you say, well, Andy, those drugs have been out for more than a decade, right. They have a dominant position in the marketplace as far as the anticoagulants of choice for people with atrial fib, right. And large insurance companies have done big data studies where they look at who has the diagnosis of atrial fibrillation, what blood thinner are they on, and then the bleeding rates of each of those groups based on what blood thinner they're taking. And consistently the new blood thinners outperform warfarin less bleeding, better stroke protection. Absolutely. Without that blood test.
Carolyn Lacey, MD FAAC: [00:25:56] I really thank you for that. That's a totally different perspective. I usually talk to my patients about how in the large randomized controlled trials, we know that the stroke rate I focused on that more. The stroke rate is the same or better than what it is with warfarin. And so that's how we know, quote unquote, that it's working. But focusing on that bleeding issue is really important for people to understand that. I think I think that.
All: [00:26:26] That's.
Andrew Benn, MD: [00:26:26] I'm glad.
Andrew Benn, MD: [00:26:26] You brought in the stroke, though. Yeah, I flipped the coin. It said, well, there's two sides of the coin to discuss and we're doing well on both. That was well.
All: [00:26:32] Made. Yeah.
Matthew DeVane, DO FAAC: [00:26:34] Well, perfect. Well, man, we covered a lot of ground this evening. That was a super important topic. We're really well done, doctor Ben, thank you for being here.
Carolyn Lacey, MD FAAC: [00:26:43] Andy, I'm going to ask you one question that I ask most of our guests that we've had on, and I'm springing it on you. I recognize that, but if you, you know, the, you know, the proverbial saying an apple a day keeps the doctor away. Mhm. If you were talking to one of your patients, what would be your apple. What do you tell them. Or what do you think is the best way to stay out of the doctor's office for however you take care of yourself.
Andrew Benn, MD: [00:27:14] If I only get one bite at that apple, I would tell my smokers to quit smoking. But everybody else, if I was looking for a really high beneficial thing to do behaviorally to and I only get one pick.
Carolyn Lacey, MD FAAC: [00:27:28] You only get.
All: [00:27:28] One.
Andrew Benn, MD: [00:27:29] Exercise because if they exercise regularly, they will get a benefit to their blood pressure. They'll possibly get a benefit to their weight, which will help their blood sugar control. And maybe, but not probably their lipids. You can show, especially for seniors, but really for anybody that people who get 200 minutes a week or more of exercise live longer and better than other people and have lower hospitalization rates. So the good news on exercise and the American College of Cardiology convened a very large committee last year to say what, really the literature had been gently driving us to for 20 years, which is when it comes to exercise, intensity is not the important thing. It's logging the minutes. You got to give me that 200 minutes a week of something. It can be a mix, it can be in big pieces, it can be in small pieces. But that like the ripple benefit we've talked about for a lot of behaviors over these few podcasts, I think exercise would give me the most bang for my buck. So for my non-smokers, I'll say that.
All: [00:28:29] Oh, I think that's great.
Matthew DeVane, DO FAAC: [00:28:30] Let's go.
All: [00:28:31] Work out.
Carolyn Lacey, MD FAAC: [00:28:31] Let's go, let's go exercise.
Matthew DeVane, DO FAAC: [00:28:33] Andy. Ben, thank you so much.
All: [00:28:35] That was great.
Matthew DeVane, DO FAAC: [00:28:35] Fantastic talk. And, uh, we look forward to having you back soon.
Andrew Benn, MD: [00:28:39] Thank you. You're most.
Andrew Benn, MD: [00:28:40] Welcome. Thank you.
Matthew DeVane, DO FAAC: [00:28:44] This is doctor Matt Devane. And on behalf of my co-host, Doctor Carolyn Lacey and our partners at John Muir Health, we hope that you enjoyed this show. And we really hope that you keep living heart smart.
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