Episode 44: Seeing ESRD as a Form of Heart Disease with Dr. Charles Herzog and Dr. Christopher Chan

The fact of the matter is that end stage renal disease (ESRD) is a form of heart disease. By the time a patient progresses to ESRD, we need to be caring and prescribing for the heart to address cardiac complications. Dr. Charles Herzog, Cardiologist and Professor of Medicine at Hennepin Healthcare/University of Minnesota, and Dr. Christopher Chan, Divisional Director of Nephrology and Professor of Medicine at the University Health Network, join this episode of Field Notes to talk about the American Heart Association's recent statement explaining how home dialysis can improve a patient's cardiovascular health and how prescribing dialysis with heart health in mind can increase the chances for successful care plans for patients.

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Dr. Michael Kraus: Welcome, everyone, to this episode of Field Notes. I'm Dr. Michael Kraus, the Associate Chief Medical Officer at Fresenius Kidney Care, and your host for this discussion today. Here, we interview the experts, physicians and caregivers who bring experience, compassion, and insight into the work we do every day. 

This episode, we're talking heart health and how cardiovascular issues and chronic kidney disease are very closely interwoven. The fact of the matter is, by the time a patient progresses to end stage kidney disease, it's the heart we need to be caring for and appropriately prescribed dialysis may address several cardiac complications and increase the chances for a successful care plan. End stage kidney disease is a heart disease. Today, we're fortunate to be joined by authors of the recent statement by the American Heart Association stating that home dialysis can improve a patient's cardiovascular health.

And here today to join us is Dr. Charles Herzog, cardiologist and Professor of Medicine at Hennepin Health Care and the University of Minnesota. And Dr. Christopher Chan, the Divisional Director of Nephrology and Professor of Medicine at the University Health Network. Chuck, Chris, thanks for being here today.

Dr. Christopher Chan: Thank you, Mike.

Dr. Charles Herzog: Thanks very much.

Dr. Michael Kraus: I'm really excited to get this started. And truth be told, they're both friends of mine, so this will be a nice conversation today. Chuck, let's start with you. What role does the heart play in kidney health, and why is it important to prescribe for the heart?

Dr. Charles Herzog: At a basic level, all vascular beds are perfused by the heart and any compromise in cardiac function will adversely affect brain, kidney, peripheral circulation. But it's a little more subtle than that for cardiorenal interactions because the relationship is very much bidirectional. So, we talk about cardiorenal effects where it's not just the heart affecting the kidney by cardiac output or by perfusion. The kidney, in its own right, affects cardiac function by changing volume, status, electrolytes.

There's also the Royce's neurohormones too, so it's very much a bidirectional effect. And as far as how do we affect kidney function by prescribing cardiac medications? Anything that optimizes cardiac function is likely to improve kidney function or at least patient well-being at some level.

Dr. Michael Kraus: The American Heart Association just came out with the recent consensus statement and its findings about administering dialysis to those who have cardiovascular disease. Can you speak to that a little bit?

Dr. Charles Herzog: It's a little bit unusual for the American Heart Association to be venturing into the home therapies or dialysis world, but it's very much the purview of the Kidney Council. And then on a larger level, a lot of patients in the United States, and internationally, have kidney disease and some have end stage kidney disease. Cardiologists are charged with taking care of these patients that promote their cardiac health. And at this point, it's very important that there be a working relationship between cardiologists and nephrologists in caring for these complex patients.

Dr. Michael Kraus: Chris, what is the role of chronic kidney disease in heart disease? And why does the nephrologist even need to know about heart health?

Dr. Christopher Chan: Well, I think you mentioned it in your introduction, most poignantly, the fact that end stage kidney disease is a heart disease. The idea that patients who have end stage kidney disease and in fact, all chronic kidney disease patients are at risk of cardiovascular complications, and in particular, patients who require dialysis are at the highest risk because they are subjected to the possibility of fluid overload, as well as the differences in their blood pressures, especially on hemodialysis.

I think we need to know that this is a significant risk factor for all our patients, and we need to be mindful of that because they are the most vulnerable group, because of their risk profile.

Dr. Michael Kraus: Chris, how does dialysis impact the heart?

Dr. Christopher Chan: I think that's a very important question. And the point of the most recent American Heart Association statement is trying to bring to light the various components of how we do dialysis. At the most foundational level, dialysis is trying to replace as much as possible the kidney function.

And hence, we're subjecting the patient's cardiovascular system to extra stress. I think we all understand that fluid is a hidden or sometimes a silent toxin that our patients are at risk for. The heart is being exposed to a cycle of fluid overload and then rapid depletion of that amount of load. In time, when this happens over and over again, we are causing a maladaptive modeling of the heart, which then causes both a hypertrophy of the heart as well as ultimately dilation of the heart and sets up for many of the complications that you mentioned, including sudden cardiac death, changes in heart rhythm or abnormalities in heart rhythm, abnormalities in terms of the geometry of the heart.

Often time, our patients are displaying blood pressures at the extreme range, the highest and the lowest. And to that aim, I think if we're trying to approach dialysis more with the aim of replacing kidney function, the more frequently we can do dialysis and the more gently we can do dialysis, the easier it is to actually allow the patients to have a better cardiac outcome.

And to that, for that reason, doing dialysis at home has that practical approach of able to offer more frequent dialysis in the hemodialysis perspective. And at night, if we can do that overnight, then that's the longest duration practically that we can provide it. And also, in terms of peritoneal dialysis, it is by definition the most continuous form of dialysis and hence the most frequent form.

So, with that in mind, I think the AHA is taking a very important statement to allow us to realize that the heart is the most common cardiovascular outcome that we need to be mindful of and more gentler and more physiological approach that we can provide dialysis, the better for the heart.

Dr. Michael Kraus: So, PD prescribed well controlling volume hemodialysis as needed with more frequency. Again, it's not about the device or where we do it, it's how we do it. I think that's exactly right. That's an important statement.

Chuck, we know you're a cardiologist, but you see an awful lot of kidney patients. How do you treat them and what's unique about them compared to your other patients?

Dr. Charles Herzog: It's not so much how unique they are, I think it's also what the level of comorbidity is, or comorbid medical conditions, because a lot of the patients that have end stage kidney disease or advanced CKD also have diabetes. So, they're linked to other diseases too. With declining eGFR, you know, volume control and other things become tougher, and the likelihood of medication side effects is a little bit more of a problem, particularly related to potassium.

There's really a bit of a break, though, when you get to what we used to call renal replacement therapy in the old days. Because then there's another aspect that you really can't control with medications and that the patient and the clinician are sort of subordinate to the therapy. It's very difficult to be using vasoactive drugs, for example, before a short hemodialysis run because sometimes the unit isn't happy with the clinician when the patient's blood pressures plummet during dialysis.

But honestly, even the mechanism or what the best way to treat blood pressures or use medications, we're still arguing about this, whether medication should be held or not before or during hemodialysis runs. So, a lot of what we do, unfortunately, is subject to mostly expert opinion and not a lot of hard evidence because some of the studies have also lagged behind the need for improving clinical science.

So, I think to me as a clinician, the main dichotomy is when the patient really becomes dependent on some type of external kidney support.

Dr. Michael Kraus: And moving back then to the American Heart Association's consensus statement. It's kind of two parts. Let's stick with the first part with you, Chuck. What does the statement actually say about fluid and blood pressure control and how they’re impacted by how we deliver dialysis?

Dr. Charles Herzog: The scientific statement basically looks at the data on what happens when you don't do it that way and do it more physiologically.

And there's no question that blood pressure control is better for any given patients. Fewer medications will be needed for control of blood pressure. And, you know, on the clinical side with better and constant volume removal and without large fluctuations and, you know, volume or the tidal nature of hemodialysis, or slowing pressure cycle from day to day, typically, after the long in or diabetic skip day, you're not going to be having too much of an issue with development of left ventricular hypertrophy and consequences of chronic volume overload. So, the reduction of structural heart disease is probably the most important thing, for my mind, along with just the fact that blood pressure is well modulated and not bouncing around a lot.

Dr. Michael Kraus: It's about that volume and pressure control. I agree 100%. 

Chris, the statement also has a very important second message. It addresses the importance of access and health equity. Fresenius Medical Care has recently signed into what's called the Zero Health Gaps Pledge at the World Economic Forum. So, we're quite aware and frankly dedicated to limiting disparities in health care. But how did this become part of the AHA statement and what does it mean to you?

Dr. Christopher Chan: I think this is a very important component. Coincidentally, this year's World Kidney Day's theme is kidney health for all. So, this is very timely. And when we're talking about access and equity, the first thing that comes to mind is awareness. It is very important for home dialysis, a more physiological way of performing dialysis, has to be known to all patients and also to providers as well, to be aware, to also understand the implication of this particular modality so that people can choose with an informed lens. I think it is equally important for us to recognize that doing home dialysis may at some times point towards the challenges of the socioeconomic differences amongst our patient populations. There are different parts of the world that have used different types of policies to help and also guide our patients. One that comes to mind would be the use of community housing dialysis that is being done, for example, in New Zealand to help patients to actually go beyond the traditional barriers, to actually have a community home dialysis.

I think it's also equally important for us to recognize that the first barrier that we have to break is really knowledge awareness. So, I applaud everybody’s efforts in trying to get to a better pledge for access and equity. And I think we are starting from a very important component to actually have kidney health for all.

Dr. Michael Kraus: Yeah, I agree. And we've been on this this campaign for a long time, Chris, long before the American Heart Association. We both agree about the importance of good home therapies in reducing disparities. Are there some points of conversation you have with your patients to just start this off to help them understand?

Dr. Christopher Chan: There is always the fear of the medical complexity of dialysis. Even PD, which by its nature is gentler and has less technology, is still sometimes viewed as an intrusion of privacy and medicalizing the home. But I think a lot of it may have to do with the understanding of why we want to do dialysis in the home and also the advantages and the clinical benefits that patients may not be aware of at first.

So once again, by doing the knowledge part, we are able to hopefully persuade and also convince people that this might be a better form of therapy for them. At times, patients may be crashing on to dialysis in the hospital and they may not even be aware that they have chronic kidney disease to begin with. The use of a nurse navigator in different parts of the world have proven to be very effective in teaching and also learning about chronic kidney disease in these type of patients that are often, if not end up in a shock state left in a in-center hemodialysis unit without any awareness of even other options.

Dr. Michael Kraus: I encourage listeners to go to Picker's empowerment, patient empowerment stuff that's been out there for 30 years or so. And because it's the steps of getting the patients to be able to understand that empowerment is more than just asking. Empowerment is getting the patient ready to make good decisions. 

And while we're on good decisions and collaboration, Chuck, any thoughts on how we ensure the statement from the AHA can help us move the needle and get the message across through the cardiologists or a collaboration between the cardiologists and nephrologists?

Dr. Charles Herzog: I think that all good medical practice now is a team approach. You know, on our campus we even talk, you know, the heart kidney team, like we have the heart team. And I think that's a very good way of looking at it. And it's not just cardiologists and nephrologists, and there's also a lot of other people that are important to a lot of nursing staff, social workers, psychologists. It really does take a village or a small city to provide good quality care to patients with end stage kidney disease. It's a very challenging group, but as a group that needs more resource allocation for effective care to be delivered, and it has to be integrated care, it can't be just people in silos taking care of patients in different clinics.

So, I think one of the things I'd like to see in the clinical and academic world is really a large effort to create these, you know, truly functional, integrated cardiorenal facilities or cardiorenal clinics.

Dr. Michael Kraus: Fascinating. Any final words, Chuck, personal anecdote or anything you'd like to share with us today?

Dr. Charles Herzog: Just that most of my contact with the patients with end stage kidney disease have been in the realm of evaluation for cardiac screening for kidney transplantation. And only a minority of the patients that come through are on home therapies. I'd have to say my informal observation is they seem to be doing, you know, as a group probably better, maybe it’s self-selection, but, you know, patients that are able to deal with their own care and being able to, you know, run PD cyclers at night or home hemodialysis machines, a lot of that will be working during the day. They can have more control over their lives, too. So, I'm not saying it's a substitute for kidney transplantation, which to me is sort of the ultimate treatment and part of also of health equity issue too for access. 

But, you know, it’s my own observation that, not as a nephrologist but as a cardiologist, that patients seem to be as a group, seem to do better when they have control of their own medical destinies and when the dialysis modality, whatever it is, can be delivered frequently and over a long period of time. And in a home setting, that's probably the best place to do it for most patients if they have the access to it.

Dr. Michael Kraus: And Chris, any thoughts you have or anecdotes you'd like to share?

Dr. Christopher Chan: I think throughout the years, it's always been an amazing fact that home dialysis is really a team sport. And the idea that we really need to integrate, and also learn from each other and also including the patients themselves, as well. Do not underestimate the willingness to learn and there are really no barriers that we cannot handle if we all work towards it.

I think the various clinical experiences that we have had and the emerging global interest in home dialysis really come from the grassroots. And I think the idea of having individualized and goal directed dialysis meet the forefront now of dialysis care. And so, I think this is a very exciting time for dialysis. We are looking into a much more individualized way of dosing, as well as prescribing dialysis. We're no longer a one size fits all type of clinical dogma, and we're looking at really personalized medicine. And this is a very exciting time, I think, for people entering into the field.

Dr. Michael Kraus: I agree. And the cardiology community is reaching out and the nephrology community working with them. Well, I think Chris, you and I have seen many patients have been quite ill doing very well with home dialysis prescribed well. And I've learned over the years that patients aren't too sick to go home, they're too sick not to go home. As we successfully treat patients living with kidney disease, we have to consider all these factors, especially heart disease.

Chuck, Chris, it was really great having you both here today. Thanks so much for joining us and providing your insight to this topic.

Dr. Christopher Chan: Thank you very much for having us.

Dr. Charles Herzog: Thanks for the invitation.

Dr. Michael Kraus: To our audience today, thanks for joining us. If you're new to the Field Notes podcast, you can download past episodes on the Apple Store, Google Play, or wherever you download your favorite podcast. Please remember to subscribe to receive the very latest updates as they happen. 

Until next time. I'm Dr. Michael Kraus and you've been listening to Field Notes by Fresenius Medical Care. Take care, everyone, and let's begin a better tomorrow.