**EP398: Stiff Old Hearts With Dr. Fiona Foo Part 1**
**Dr. Auric Bishop:** Welcome, my name's Dr. Auric Bishop. I'm a cardiologist, an author, and a keynote speaker. I'm the CEO of the Healthy Heart Network. I'm all about trying to help people live as well as possible for as long as possible. Heart disease is huge in Australia. Every 20 minutes, someone suffers a heart attack. Most of these could probably have been avoided if only we knew what to do. This podcast is all about helping you understand blood pressure, weight, cholesterol, for better health. If you enjoy this podcast, I would be honoured for a five-star review. You can share it with your family and friends. It may well save someone you love.
**Dr. Warwick Bishop:** Hi, my name is Dr. Warwick Bishop, and I'm absolutely delighted you've joined me on my podcast and videocast station. But I'm even more delighted today. I have a colleague, Dr. Fiona Foo, who's a cardiologist who has been on the podcast before. The reason I'm super pleased that she's joining us is from her previous podcasts, which were on climate and environment. I had remarkable feedback. I had people reaching out and letting me know how informative, how organized, and clearly how clever she was in the space. So I'm going to introduce Fiona. How are you?
**Dr. Fiona Foo:** Yeah, great! Delightful to catch up with you, and I really do appreciate your time.
**Dr. Warwick Bishop:** Fiona, for those listening, is busy as a fly at a barbecue. She's got so many fingers and so few pies, or so many pies and so few fingers. She's so busy with interventional work, with prevention work. She works at the Sydney Cardiologist Group. She does on-call. She has all sorts of interests, and we're not going to dive into all of those today. Oh, and while I think of it, for those who may have missed Fiona's previous podcasts, they are number 348 and 349 of my podcast series. 348 and 349. And we're talking about climate and cardiovascular disease. Really interesting. Anyway, how are you today, Fiona?
**Dr. Fiona Foo:** Yeah, fantastic! One of the really nice things about your practice is you've oriented it towards some of the issues that we see with female patients. Today, we've selected heart failure with preserved ejection fraction as a topic that I think is really important broadly in the cardiovascular community but also really important for women.
**Dr. Warwick Bishop:** For those listening, can you explain what heart failure with preserved ejection fraction is in layman's terms?
**Dr. Fiona Foo:** So, as your listeners may know, we've got heart failure, which... I guess people think of it as the heart not pumping well. And so that's mainly heart failure with reduced ejection fraction, where the heart is not contracting well and pumping the blood out. Whereas heart failure with preserved ejection fraction is where the heart doesn't relax well. So it's that kind of stiff heart that doesn't relax well, but it presents very similarly. You get similar heart failure symptoms. The main symptom is shortness of breath. They could get fluid on their lungs, or they can't lie down flat, but they get similar symptoms to that heart failure with reduced ejection fraction where they don't pump well, but this one is where they don't relax well.
**Dr. Warwick Bishop:** So for those who like a visual, and I'm a bit of a visual person, if I can offer this, Fiona, I often think of a squeeze box or a piano accordion. If you can't squeeze it very well, so as you try to squeeze it in, you've got weak power or the squeeze box doesn't work very well, then that's heart failure with reduced ejection fraction or reduced squeezing power. But if you've got a squeeze box that's really sticky and old and you can't pull it apart, that's heart failure with preserved ejection fraction. So it's sticky; it doesn't relax very well. So maybe that's a nice visual for people who are listening in.
The other thing you mentioned there, which is age, is actually quite important because heart failure with preserved ejection fraction actually increases with age. It is one of the biggest risk factors, and we know that the prevalence and incidence—the amount of heart failure preserved ejection fraction—is actually increasing and it's increasing relative to that of reduced ejection fraction. That's partly because of our aging population, but also due to some of the other, I guess, risk factors for heart failure preserved ejection fraction, including hypertension, obesity, diabetes, and atrial fibrillation. So these are all risk factors that increase heart failure with preserved ejection fraction, and that increases with age. We're seeing this rise of heart failure with preserved ejection fraction in the general population.
So to bring our listeners in on a bit of medical jargon and to save you the mouthful of heart failure with preserved ejection fraction—which is a huge mouthful—why don't we use the terminology that cardiologists use, which is an acronym: heart failure (HF) with preserved (P) ejection fraction (HEF-PEF). So why don't we call it HEF-PEF?
**Dr. Fiona Foo:** Yes, thank you! Making our audience so much smarter and in the know, and it will make your—you won't get tongue-tied on that HEF-PEF.
**Dr. Warwick Bishop:** So look, age obviously is one of the really important risk factors, but what are some of the others? And women are important in this cohort as well, aren't they, Fiona?
**Dr. Fiona Foo:** Yeah, so let's talk about women first. Essentially, women outnumber men by about two to one, and it increases particularly when they get older with post-menopause. So that older female is one of those bigger groups. They talk about different groups of HEF-PEF. Think about that older female often who has hypertension; they are a big group of people with HEF-PEF.
Then there's another big group of HEF-PEF patients that are this kind of metabolic, inflammatory, overweight, and obese group. They actually have quite a high risk of heart failure, hospitalizations, and issues. The biggest risk factors that we're going to go through are things such as, so age was one of them, but then high blood pressure, obesity, and diabetes that I've mentioned. Atrial fibrillation is a contributor, COPD (chronic obstructive pulmonary disease), and lung disease. Chronic kidney disease, I think, are some of the ones that we'll talk about. There's also some heart artery disease, but that's more non-obstructive heart artery disease that we'd mentioned previously with females as well.
**Dr. Warwick Bishop:** So when we're thinking about a heart that's not relaxing very well, what are the sort of symptoms that someone might get from that? Obviously, as we age, we get... Well, I'm a little bit older than I was 20-odd years ago, and I have to admit, I don't run quite as well. I get a tiny bit puffier than I used to, and I think it feels to me like it's normal aging. But for people who are getting older, what sort of signs or symptoms might they notice as they're getting older, but potentially might be getting HEF-PEF? How does that work?
**Dr. Fiona Foo:** So I think, yeah, it is hard to differentiate, you know, whether you're getting shorter breath from just being older and less fit. Ultimately, you know, we have to—it's like that constellation of symptoms. The main symptom is shortness of breath on exertion. But then you can present acutely with shortness of breath, you know, when you lie down flat. Fluid on the legs, like that accumulation of leg swelling, is one of those symptoms. Those are the main things. To diagnose it, you can have those symptoms, but then you also have signs of fluid on your lungs or on a chest X-ray. One of the other important things that we can test for, mainly acutely, but I guess also chronically, is something called BNP. An elevated level of BNP, which is a brain natriuretic peptide in the blood, goes up.
**Dr. Warwick Bishop:** Before we come, we'll talk a bit more about brain natriuretic peptide because it's a really fascinating space, I think. But before we do, one of the things you said is that when people lay down, they can get shortness of breath. Some people may be listening to that and thinking, "That's a bit odd. Why would it be when you lay down that you get shortness of breath?" Do you want to speak to that for a moment?
**Dr. Fiona Foo:** So, yeah, I also mentioned that apart from laying down flat, they wake up short of breath. So, yeah. You can add more to this, but mainly the fluid on your lungs and all those increased pressures in your heart, I think that just kind of cause you to be so short of breath that you cannot lay down flat to sleep.
**Dr. Warwick Bishop:** So I've often thought of it myself, and correct me if I'm wrong, but as our hearts fail to work properly—HEF-PEF, or heart failure even with reduced ejection fraction—the body holds on to a bit of extra fluid. That extra fluid is the compensatory mechanism that's driven by the receptors in our body. Our receptors in our body evolved two million years ago in our evolutionary ancestors, and they're all geared up so that if we got bitten by a saber-toothed tiger and we lost some blood, our body would hold on to fluid as well as possible so that we could re-establish that blood.
Now, fast forward to the current day and fast forward from our ancestors who would live to 20, 25 years of age to people who are living 60, 70, 80, 90 years of age. What now happens is if the heart's not working well, because it's not delivering the pressures to those senses in our body, our body thinks, "Wow, maybe we're on the African plains. Maybe we've lost a bit of blood because we got bitten by a saber-toothed tiger. Let's hold on to some of that fluid." Unbeknownst to it, the body actually hasn't lost any fluid. The consequence is more fluid in the body of someone with heart failure as they're standing around in the kitchen doing their shopping, whatever it might be. A lot of that fluid moves with gravity to the dependent parts of the body. That may cause engorgement in the legs. You touched on swelling in the legs. When those people lay down, that redistribution of fluid throughout the body—almost equally, because gravity is equal when you're laying down flat—means that more fluid can roll into the lungs. If more fluid rolls into the lungs, the lungs can be quite stiff because there's more blood in the arteries and in the capillaries of the lungs, and stiff lungs make you short of breath. So that's a nice way to sort of think about it.
**Dr. Fiona Foo:** I think it's fascinating. And for those listening, it's just so cool because what we're really thinking about is an evolutionary adaptation that sort of goes wrong as we get older in our modern society.
**Dr. Warwick Bishop:** Yeah, I think that's so cool, actually.
**Dr. Fiona Foo:** Yeah, no, that's... and I think that waking up short of breath and not being able to lie flat is a very sensitive symptom of heart failure. One interesting other one in severe heart failure is actually bending over and getting short of breath. I never really thought about that until someone pointed it out; that is quite a severe symptom.
**Dr. Warwick Bishop:** I will say, and this is a plug for me, but if anyone is after any more information, we cover some of these concepts in a lot of detail in *Cardiac Failure Explained*, which is one of the books I've written to help people understand their journey through heart-related issues. Now, back to brain natriuretic peptide, Fiona. Sorry to have jumped in there, but I love that sort of positional shortness of breath issue.
**Dr. Fiona Foo:** I think with the brain natriuretic peptide, I guess for your listeners in terms of what it is, essentially it's something released in your blood that increases particularly with heart failure. So it's elevated if you go into both HEF-PEF and acute heart failure or even in HFREF as well. They can use it to guide management. It's useful because if you come into emergency departments or even see your GP with shortness of breath, you can send that blood test. It's very specific for being from your heart rather than being from your lungs. If you have an elevated BNP, then it's more likely that you have heart failure rather than it being from your lungs, like that shortness of breath.
**Dr. Warwick Bishop:** You're quite right. And for those listening, what Fiona's just said there about the role of brain natriuretic peptide in trying to discern between shortness of breath from the lungs or from the heart is absolute gold. Sometimes people are just really hard to assess. You can't be sure whether it's the lungs playing up or the heart playing up. A very clear indicator on one of these tests can give you a really, really good idea.
I'll add a little bit there on brain natriuretic peptide. There are a number of peptides—atrial natriuretic peptide, brain natriuretic peptide. There are a number of peptides that are released by the heart when it's under strain. These peptides actually have a role. You may have heard in the name "natriuretic." That means they make you pee. These hormones, these chemicals released by the heart, actually take load off the heart and protect the heart when it realizes it's under strain, which is so cool.
What's really, really cool about that is some of the therapies that we've got for treating heart failure now act to reduce the body's breakdown of those chemicals so they float around even more and help with natriuresis, passing fluid, vasodilation, opening up the arteries, taking pressure off the heart, reducing inflammation, and helping the heart return to its normal shape. So it's a really important space. These natriuretic peptides are so important in not just diagnosis, but we also tap into them in therapy.
**Dr. Fiona Foo:** Yeah, particularly that is in heart failure of reduced ejection fraction, the Entresto medication for that.
**Dr. Warwick Bishop:** Yeah, 100%. Super important. So we talked a bit about what heart failure can look like in terms of the heart being stiff. We've talked a bit about some of those symptoms. Do you want to talk about the risk factors? I think we should talk about the risk factors. We've talked about diagnosis a little, and we might get to the end of that. Because there's such a lot to talk about, we might come back for a part two, if it's all right with you, and cover management and then prevention strategies or prevention strategies and management, something like that.
**Dr. Fiona Foo:** Sure.
**Dr. Warwick Bishop:** Okay. So we've got—let's cover risk factors and then we'll draw a line under it there and then come back.
**Dr. Fiona Foo:** Yeah. Okay. So as I said, age is one of the most important ones. Hypertension and obesity account for about two-thirds of HEF-PEF. Hypertension, particularly, most patients—up to 90% of patients with HEF-PEF—have hypertension. When someone has high blood pressure, they get that very stiff heart. That kind of adds to that impaired relaxation that comes with HEF-PEF. So it's very important to treat that.
When we talk about females, high blood pressure is an even greater risk factor for HEF-PEF in females. Then if you talk about obesity, again, nearly 80% of patients with HEF-PEF are either overweight or obese. That's another big risk factor for HEF-PEF. They've found that every increase in your BMI is associated with an increase in your risk of HEF-PEF. Again, getting back to females, obesity is more common in women than men, particularly after menopause, and that increases their risk.
Some of these risk factors explain why women have a greater risk of HEF-PEF after menopause, where all these hypertension and obesity, as well as diabetes, also increases. Then there's diabetes. Nearly 30% to 40% of patients with HEF-PEF have diabetes, again, greater in women. Diabetes increases the risk of heart failure more in women.
With all those traditional risk factors, they seem to affect women more, particularly after menopause, increasing the risk of heart failure but also of coronary artery disease. Some of the other ones—chronic kidney disease can increase risk. That's quite a high risk; what we call phenotypes have very worse outcomes if they have bad kidney problems with HEF-PEF. Coronary artery disease is common. You can get obstructive coronary artery disease, which often causes heart failure with reduced ejection fraction if someone has a big heart attack, and it can cause that impaired heart function.
But often in patients with HEF-PEF, they have non-obstructive coronary artery disease, and they have something called coronary microvascular dysfunction, which we talked about with the previous female and heart artery disease. Problems with the small vessels of the heart are actually very common in patients with HEF-PEF. Atrial fibrillation is actually one of the biggest problems because that comes with age, obesity, high blood pressure—all of these shared risk factors—and that increases the risk of developing HEF-PEF.
**Dr. Warwick Bishop:** It's kind of what, I don't know, chicken or egg, like, you know, which comes first?
**Dr. Fiona Foo:** Yeah, they're sort of linked, aren't they, really?
**Dr. Warwick Bishop:** Yeah, correct.
**Dr. Fiona Foo:** Other ones include COPD (chronic obstructive pulmonary disease) and obstructive sleep apnea. Those lung issues, as well as sleep apnea, can also contribute. With the lung issues, it comes back to that BNP because some people do present with both. They may have heart failure but also have emphysema or bronchitis to cause their shortness of breath.
Before we finish, I'll just touch on, apart from the women issue, we've got those traditional risk factors that increase the risk, particularly after menopause, of heart failure of HEF-PEF. But then they've also got sex-specific risk factors. The biggest one I think I just want your listeners to understand is some of the hypertensive disorders—those pregnancy disorders. Hypertensive disorders of pregnancy particularly increase your risk of further hypertension. They have an increased risk of heart failure of HEF-PEF, as well as some other things like gestational diabetes, autoimmune disease, and some breast cancer. They can increase the risk of heart failure, mainly heart failure with reduced ejection fraction, but also heart failure like HEF-PEF as well.
I think touching on those gestational-related cardiovascular issues is really, really important. But I think also touching on people who've gone through chemotherapy—we do see that chemotherapeutic agents can have an impact on heart function. An awareness of that is really important.
So look, I think this is a great place to pause. I'm so excited because we can come back and do a part two. We've introduced the concept of HEF-PEF. Everyone who's listening knows what HEF-PEF is now—heart failure with preserved ejection fraction, not reduced ejection fraction. We've talked about what symptoms people may get. We've talked about some of the diagnosis, and we've talked about the risk factors.
So I'd really like to come back and talk about how we manage it. Then I'd like to talk about some of the preventative strategies and what people really should be aware of. For now, I'm going to say thanks so much, Fiona, for sharing. For those listening, as always, I'm super grateful that you bothered to listen. I am really, really grateful when people offer feedback. If you thought Fiona was fantastic again, please let me know because otherwise, we do this stuff in isolation. You think, you know, are you making a difference? Are you helping people? So it's hugely satisfying and gratifying if people reach out and say, "That was great," or "I learned this." So please let me know.
If you do like it, share it. I know if you're one of Fiona's patients, there's a very good chance she will have directed you to this to have a listen so that you could get more information because there's almost never enough time in a consulting session. This is a great way to get more information, more depth. It's been a pleasure sharing with you, Fiona. I look forward to coming back. And for those listening, I hope you live as well as possible for as long as possible. Take care and bye for now.
**Dr. Auric Bishop:** Hi, ever wondered what your risk of heart attack is? You should. It's the single biggest killer in the Western world. We're talking one death less than every 30 minutes in Australia, one death less than every 60 seconds in the United States—9 million deaths globally per annum. Well, how do you check your risk? You can go to www.virtualheartcheck.com.au. You'll find out about your risk and what can be done beyond that to be even more precise.
