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Geriatric Cardiology and "Pump Head" Revisited: Podcast with Liz Whitlock and Mike Rich





A September 2000 New York Times article titled, “Sometimes Saving the Heart Can Mean Losing the Memory” describes a relatively newly described phenomena of difficulty with memory and other cognitive tasks six months after cardiac bypass graft surgery, or CABG.  The syndrome was termed “pump head.”  A doctor is quoted in the article as stating that older patients he might have previously considered CABG for he would try to manage medically, with a stent.  Data on the impact of CABG on cognitive function over the subsequent 20 years has been mixed.  The problem with these prior studies is they enrolled patients at the time of the CABG.  They didn’t have a sense of what the cognitive trajectory was before the procedure.


In this context, enter Liz Whitlock’s study published this week in JAMA comparing cognitive trajectories before and after CABG versus stenting procedures.  Liz finds no difference in the decline in memory before or after CABG vs PCI - in other words - their memory continued to decline at the same rate after each procedure as before.  Furthermore, a newer procedure intended to spare patients the risks of bypass, called “off pump” CABG, was found in this study to be associated with greater memory decline than on pump CABG.


Pump head, it seems, is not a thing.  Those who get CABGs likely also had vascular disease in the brian that was leading to a steady cognitive decline before the procedure.  


To contextualize these findings for practicing geriatricians and other PCPs, we are joined by Mike Rich, one of the early movers and shakers in the field of geriatric cardiology.  We are doing these cardiac procedures on ever older and older patients.  What should we be concerned about?  How should we counsel our patients? Listen to find out!


-@AlexSmithMD




  


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TRANSCRIPT

Eric: Welcome to the GeriPal podcast. This is Eric Widera.

Alex: This is Alex Smith.

Eric: And, Alex, who do we have with us today?

Alex: Today we are delighted to welcome Liz Whitlock, who is Assistant Professor of Anesthesia and Perioperative Care at UCSF. Welcome to the GeriPal podcast, Liz.

Liz: Thanks so much.

Alex: And we have Mike Rich who is Professor of Medicine and Cardiology at Washington University in St. Louis, which is distinct from the University of Washington in Seattle and also has a long-standing interest in geriatric cardiology, as one of the early movers and shakers in the field. Welcome to GeriPal podcast, Mike.

Mike: Thanks, Alex and thanks for having me.

Alex: I should also mention Mike is additionally one of the associate editors at the Journal of American Geriatrics Society and has been involved there for a long time.

Eric: We're going to be talking about journals. We're going to be talking about Liz's paper that just got published in JAMA on CABG versus PCIs in memory-declining older adults undergoing coronary revascularization. And in general, the idea of what is geriatric cardiology and geriatric anesthesiology. So we got a lot to talk about, but before we get into that, we'll start off with a song request. Liz, do you have a song request for Alex?

Liz: Well, Alex, I thought based on the topic of today's conversation, perhaps How Can You Mend A Broken Heart by the Bee Gees would be appropriate.

Alex: All right, just a little bit.

Eric: I want to hear this one.

Alex: Stretching my vocal range here again. (singing)

Eric: That was fabulous, Alex.

Liz: Nicely done.

Eric: I remember I watched the Bee Gees documentary a couple months ago. Fascinating. Three brothers from Australia.

Alex: Oh, I didn't know they were brothers. They don't look like brothers on the YouTube video I saw.

Mike: I didn't know they were from Australia, I thought they're from UK.

Eric: I mean, it's a while ago, it's been a couple months. I thought they were from Australia. I could be wrong. Well, how about we move from the Bee Gees to mending broken hearts? Liz, I'm going to start off with you. We always talk about... A, first of all, big congratulations on the JAMA paper. Really amazing. We're going to talk about that JAMA paper, but we always like to hear, how did somebody get interested in this type of work, especially round your publication with whether it'd be geriatric cardiology or geriatric anesthesiology for you, Liz.

Liz: I did a fair amount of research in medical school with actually one of the coauthors on this paper and yet had a very poor grasp in medical school of course of what it's like to be an anesthesiologist and what sort of things patients would bring to me as far as their concerns and the reality of postoperative recovery for older adults. And what I started to be struck by in residency was that the reality of recovering from major surgery for older adults seemed a lot tougher than I had appreciated as somebody who had a tangential participation in the postoperative care.

Liz: There are some things we can do intraoperatively to help older adults but fundamentally I started to be really interested in making sure that major operative interventions were aligned with an older adult's goals; that they had a really good grasp of what they were getting themselves into, that they knew what the anticipated risks and benefits of the surgery were. Even sort of amorphous ones like cognition, which is what we're going to be talking about later. And helping older adults understand what it might look like for them as they recovered from a major surgery and certainly, CABG revascularization is a major surgery indeed.

Eric: And Mike, how about for you, how did you get interested in the idea of geriatric cardiology?

Mike: Well, when I did my cardiology fellowship back in the early 1980s, my original interest was in acute coronary care. That was a really hot time in cardiology. That's when thrombolytic therapy and angioplasty first became available. But when I was working in the CCU, we were having a pretty high volume of older patients with acute MI and acute coronary syndromes. Upwards of 50% of our patients were over the age of 70, 20% were over the age of 80.

Mike: And I went to the literature to try to see what we knew about acute MI in this age group; there was virtually nothing published. And that's how I originally became interested. I thought it was a real opportunity to do some important work to contribute to the field and later evolved into interest in heart failure, atrial fibrillation and other areas of cardiovascular disease in older adults.

Alex: I wonder, Mike, because you've been around for this, the development of the field of geriatric cardiology, if you could give us an overview of what are the hot-button issues in geriatric cardiology? I don't know if that's the right term, but what is different about older adults and cardiology? You mentioned a few. Acute coronary syndrome, anticoagulation, heart failure. What makes cardiology in older adults different?

Mike: Well, I think that perhaps the most important thing, as in medical care for older people in general, is that the complexity of the condition, as well as the treatment, becomes increasingly great as people get older, with more comorbidities, psychosocial issues, family issues and so forth. But also, aging is associated with substantial changes in cardiovascular structure and function, which alter responses to disease and to treatments for disease. So I think that it really takes a much more nuanced and patient-centered approach to really provide optimal care to the older patient with any condition, but particularly cardiovascular disease, which is my area of interest.

Alex: And for our listeners, who may be practicing geriatricians or clinicians caring for older adults, when should they think about... when they refer, can they refer to a geriatric cardiologist or is that only in highly specialized centers like Washington University?

Mike: Yeah, there's quite a few. In the American Cardiology, there's a geriatric cardiology section, which has some 1,000 to 1,200 members and if one wants to identify a local geriatric cardiologist, it's possible to search the database and try to find someone. But the truth of the matter is that pretty much all cardiologists are reasonably well-versed in the care of older patients for the simple reason that a large proportion of our patients are older. In recent years there's been greater awareness amongst cardiologists about some of the truly geriatrics issues, and that has been stimulated in part by the emergence of TAVR as a therapeutic option for older patients who previously were considered inoperable or for whom there was no good treatment option for severe aortic stenosis.

Mike: And we've learned that even with TAVR, that older individuals who are frail or who have poor functional status aren't necessarily going to get a good result with TAVR, even though you can fix the valve, you can't necessarily fix these other issues. And so I think that that's for... A large proportion of cardiologists put aging and geriatrics and frailty on their radar screen and something that they will consider in deciding whether or not to refer a patient for TAVR or any other type of invasive procedure, including CABG.

Alex: And you mention TAVR, Eric's going to talk about or talked... I guess, by the time this comes out, the literature update will be over and Eric will have talked about it.

Eric: Yeah, I think Ken's going to be talking about functional status after TAVR.

Alex: At the AGS Plenary and for those of you who didn't see it, you can catch it online. And then the song to go with that is My Heart Will Go On. (singing)

Mike: You know, Alex, you had asked earlier, some of the hot-button issues in geriatric cardiology. Well, function is one of them, definitely. How do we optimize function in our cardiac patients? Sort of a almost de-emphasis, a little, certainly not completely ignoring longevity in talking about the impact of our therapies but trying to optimize function, which tends to be of great importance to our older patients.

Alex: Yeah. And keeping in mind when we're talking about function, we're talking about physical function of the person, as opposed to optimizing cardiac output, which may improve physical function of the person. But I think helping cardiologists see that the bigger picture is one of the important contributions that geriatric cardiology has made to the field.

Eric: That's why I really like Liz's JAMA paper, because when we think about outcomes in cardiology, it's not just about survival that older adults care about. They care about their physical function and they also care about their cognitive function. How about we get into the paper right now, which I think is fascinating looking at memory problems because my bias, I guess, was, "Oh, this is a no-brainer." Older adults are going to do better with a PCI as far as cognitive function. What's the big deal here? Liz, I'm going to turn to you. Why did you even think or conceive of this paper?

Liz: So, here's the thing, we anesthesiologists have been mulling over postoperative cognitive change or postoperative cognitive dysfunction for decades and as a thing it was sort of first demonstrated after on-pump major open heart surgeries where first people were looking at the cardiac bypass pump is maybe causing long-term cognitive deficits. You can identify cognitive decline in something like a quarter, maybe more, of patients following their CABG surgery and people were saying that this is awful. This is a public health problem; we are harming older adults by doing these procedures.

Liz: And it trickles down where news media presents an anecdote of somebody who really had a terrible cognitive outcome after surgery and couples it with evidence looking at cognitive testing in a large population of older adults. And then the morning of surgery, a patient comes to me and says, "Hey, I heard", or "I know somebody who knows somebody who had really bad cognitive outcome after surgery." And they're coming for... Maybe they're coming for a major cancer surgery because they would hope to have another four or five years of life instead of six months. Maybe they're coming for a knee replacement where they've been functionally impaired for years, maybe on opioids, uncomfortable and not exercising. And they say, "Hey, what about this thing that might happen to my head?"

Liz: It's really difficult to reconcile, because you expect you want to be helping people. When I take somebody to the operating room, I want to know that the surgery is going to help them achieve their goals, whatever those are. And if I can't talk intelligently about the risk of cognitive decline and how cognitive change after surgery might fit into somebody's long-term cognitive outcome, I'm under-prepared to just explain to them what to expect post-op.

Alex: And isn't there some guideline from some professional society that you're supposed to talk about?

Liz: Yeah. Well, we've got some guidance that has been published in major anesthesia journals that we should be talking about. First, delirium. Immediate, postoperative cognitive change with people who are at risk. But then also, potentially longer term cognitive change in all older adults; 65 and older; the risks of it. I'd love to be able to do that. It seems like the right thing to do. The people who wrote these guidelines are people who were immersed in this literature.

Liz: But I ran into a problem where I could tell you that you have a 15 to 20% risk of scoring one to two standard deviations lower than your predicted postoperative cognitive outcome at six weeks or three months or something like that in there, but I couldn't tie it back to being able to read the newspaper or find your keys or other things that are important for life. I could just tell you about standard deviations. And that to me didn't feel like consent. It didn't feel like a conversation about what mattered.

Eric: Can you describe a little bit about what you did in this paper?

Liz: Yeah, so we used a population-based cohort of older adults in the Health and Retirement Study. These are older adults throughout the United States who said, "Hey, go ahead and call me up every couple of years and ask me hours of nosy questions", or in person, and they get cognitive testing as well. And every two years, no matter what happens to them as they age, the HRS contacts them and checks on how they're doing and they do a battery of fairly simple cognitive tests.

Liz: And in the course of normal medical care, towards the end of life, some of these older adults had open heart surgery to revascularize coronary artery disease. So they had CABG surgeries, and some of them had PCI, a much less invasive intravascular version of opening up those blocked heart arteries. So we collected the people who had CABG or PCI procedures and we looked at what happened cognitively to them after their procedure, but also before, because we had that data just from their participation in the cohort.

Eric: And I guess my question is, are these comparable groups? I would imagine the groups that are getting CABGs are different than the groups that's getting a PCI. I'm trying to figure out which way would be worse. I mean, I think if they're sicker, they'd probably avoid CABG. When they're healthier... I don't know. How should I think about this?

Liz: Well, there's definitely a cardiological reason. You don't go and do a CABG on somebody that you could revascularize using a PCI. Usually the people who get CABGs have more... I'm sort of not in my lane here. There's a cardiologist on Hollywood Squares here right next to me.

Eric: But it's probably like a bell-shaped curve, right? Or a U-shaped curve. Less cardiac complications issues, you're probably getting PCIs. But the sicker you are, you're also probably getting PCIs. And there's probably a goldilocks of where somebody would get a CABG. Is that right, Mike?

Mike: Yes, so patients who're undergoing CABG do tend to have more severe coronary disease. They don't have a single vessel that could be easily treated with a PCI. But they also often tend to have more severe left ventricular systolic dysfunction because we have data from the cardiology literature indicating that LV dysfunction is a marker for better outcomes with CABG as compared to PCI. So you're right, Eric, these tend to be different populations and therefore this needs to be dealt with in the context of the paper. And so I'll turn it back over to Liz.

Eric: [crosstalk 00:18:02] Statistic were done [crosstalk 00:18:05]

Liz: Well, I actually want to point out one thing because we can certainly complain that the PCI and CABG recipients are not well-matched at baseline, and then you can do some math magic in how I tell you they're perfect. Whatever. But actually, there's a fair amount of comparisons in the literature looking at cognition; specifically after CABG; that didn't use a group of people with heart disease at all.

Liz: They compared it to people recruited from a senior center and they said, "Hey, these people who had heart surgery did worse cognitively than healthy older adults from a senior center." Actually, one of the things that I specifically wanted to do in this work was find an appropriate control patient population for people who had severe enough cardiac disease to need revascularization. And for that, the obvious control group is PCI, not just medically managed cardiology patients or healthy older adults waiting for a knee replacement.

Eric: So, how did you account for, or did you account for... is the differences between indications between the two groups? And who would get it.

Liz: We weren't able to account for cardiology indications. We don't have left ventricular systolic function. We don't have what territories were impacted by the coronary artery disease. But we have diabetes, hypertension, prior strokes, some measures of functional status, independence and activities of daily living. We have a palate of factors that we could try and balance for. We did that using statistics and we used a second methodology called propensity-score weighting, where we try to calculate how likely someone was to get a PCI versus a CABG and then up-weighted the people who looked like... to match the cohorts better.

Liz: Because we could alternatively try and use math to make them look like a fake, randomized trial to balance that. It's a slightly different methodology though also based on regression modeling. So, trying two different ways, they agreed, which was reassuring.

Eric: And then I guess the question is, what did you find?

Liz: The primary analysis, what we said we really wanted to study, was whether the rate of cognitive change prior to the surgery or PCI was different from the rate after surgery or PCI. Did you have an acute change in your cognition at the time of your revascularization procedure?

Eric: Mike, real quick, before you read this article, what do you think that they would have shown?

Mike: I was surprised at the results of the article. I expected that patients who underwent CABG would have more rapid progression of cognitive decline, however that sort of underscores the importance of this paper. And part of the reason why I would've though that is that as referenced in Liz's paper, I think it's the first reference, there was a paper in New England Journal about 20 years ago, which indicated that following coronary bypass surgery there was significant rate of cognitive decline and it had persisted for several years. And I actually referenced that paper in many review articles that I wrote, book chapters on the topic.

Mike: Later it became a... Those findings were questioned for the exact reasons that Liz is saying, is that it didn't have any information about the pre-operative rate of cognitive decline to compare the post-operative rate of decline against. So, that's I think a very interesting aspect of this particular study; looking at the rate of decline before the procedure, after the procedure, has there been any significant changes, and perhaps more importantly, were there any differences between the PCI group and the CABG group?

Eric: So, Liz, what did you find?

Liz: No difference. Right? So if you model a cognitive change, or potential for cognitive change at the time of the procedure, and there is none, and whether you have a CABG or you have a PCI, and after the procedure the rate of cognitive change in both groups was totally indistinguishable. The lines are basically right on top of each other. So based on this, after looking at whether there was an acute change and whether the long-term cognitive outcome was different between open heart CABG surgery and PCI, there's no difference.

Mike: So, this was after five years and I think it's very reassuring for us as cardiologists. We can tell patients, "Well, we now have good data acknowledging it's not a randomized trial, but we have good data indicating that the rate of cognitive decline following bypass surgery is no different than it was have you not undergone bypass surgery, and no different than if you'd have PCI instead." And I think that that's clinically valuable information for cardiologists and also for other clinicians, geriatricians and others, who are talking to their patients about some of these options for treatment of their heart disease.

Liz: And we were thinking that if there was going to be a difference, we should see a really big signal, because when you have a CABG, you're exposed to a tremendous number of things that we think should be cognitively impactful. Obviously, anesthetic medications have been implicated in in-vitro particularly studies. So you're exposed to general anesthetic; you go on the heart-lung bypass pump or you have a surgery without the pump, which we can talk about later and you go to the ICU, you're intubated with a breathing tube.

Liz: You probably have higher rates of postoperative delirium, which is reliably associated with adverse long-term cognitive outcomes. You're in the hospital longer. You're healing this trauma. It's inflammatory. There are tons of things that should make your cognition worse after CABG compared to PCI. And the fact that we saw them so tightly opposed, is really remarkable.

Eric: And Mike, when you think about this from a geriatric cardiology perspective, this article, does it change at all how you think your practice... or where we should go from here or do you still have a lot of questions about the article?

Mike: Yes, so I think that an important limitation of this paper, and I'd like to hear Liz's thoughts about this as well, is this provides a great reassurance that overall cognitive function is not really significantly impacted by bypass surgery over the long run. But we still do have the short-term effects, which we certainly know that delirium is going to be much common after bypass surgery in this population compared to those who are undergoing PCI.

Mike: And so I think that that still is an important aspect of it. I think we can reassure our patients about the long-term effects, but we still have to deal with a higher risk of these important cognitive effects in the short-term following the procedure; and what we can do to minimize those effects; minimize the occurrence of delirium and if it does occur; how do we optimally treat it.

Liz: Yeah. I completely agree with that and we very deliberately did not make any conclusions about the immediate postoperative period, because there is no reason to think that somebody who's had their chest cracked open would feel totally back to normal six weeks later even, although we would hope that for our patients. That's a big trauma. That's a big deal in your life and compared to PCI, where you probably would feel pretty much back to normal. It's just not fair to compare those. So older adults should be warned that there are a lot of things that can be pretty unpleasant about postoperative recovery from a CABG.

Liz: But there's no evidence based on this work that the long-term cognitive outcome is bad. And there had been some questions about that, whether, five years after a CABG, maybe that's when you sort of manifest a higher rate of dementia. We modeled that and also didn't see a difference there. But if the CABG revascularization is the right one for the heart disease that you have and you're an appropriate candidate, there's not a cognitive reason not to proceed with that, for long-term outcomes.

Mike: I think another important observation from this study was the comparison between off-pump and on-pump bypass surgery, so off-pump surgery became popular in part because of this New England Journal paper in, I think it was 2001, and the concern that maybe it was an effect of the bypass pump itself that was impacting cognitive function in these patients. And so off-pump techniques were developed and... What did you find in this study on the comparison between off-pump and on-pump?

Liz: We had a pre-specified comparison between on and off-pump and the hypothesis going in should be that off-pump CABG, which was in part developed to avoid the hypothesized cognitive impact of cardiac bypass pump exposure. The hypothesis would have been that the off-pump people would do better and in fact we found that the on-pump people did better. The off-pump people were the only ones who had an acute change in their cognition and acute worsening of cognitive trajectory that, if you modeled it out, was sustained until the end of the modeling timeframe.

Eric: Why is that?

Mike: I think it has very important implications for surgical practice and surgical anesthesiologists and pump technicians and so forth, that probably off-pump surgery at least, with the objective of trying to minimize post-op cognitive change should be pretty much abandoned, based on this study.

Liz: Yeah, and I want to; if you'll let me, I'll talk you through what it feels like to be in the OR, on the anesthesia side, during an off-pump CABG.

Alex: Yeah, I want a visual of what's that like, like surgeon trying to operate on the beating heart?

Eric: Well, the one thing I did learn from Liz was that anesthesiologists have a very hard time picking songs; I'm guessing that comes from the OR; who gets to decide who plays the songs.

Liz: Yeah, we're never allowed to pick the music. It's very nerve-racking for us.

Eric: Sorry Liz, go ahead. Tell us what it's like.

Liz: Well, so I was exposed to off-pump CABG through my residency only. I'm not a cardiovascular anesthesiologist, that's a specialty of anesthesia, but through my two months of cardiac anesthesia, what I remember is often CABGs are terrifying for the anesthesiologist. It can be because, as you point out, Eric, the surgeon has to operate on this beating heart, but the heart has not conveniently put all of its blood vessels in the front where you can get to them. There are special devices that are trying to stabilize the heart. It's not perfect, but it's pretty good.

Liz: But where it became really nerve-racking for us was that the surgeon sometimes has to kind of lift up and twist the heart a little bit and you'll watch the blood pressure go down. And eventually you're like, "Okay, please untwist the heart. Let them reperfuse. Let the heart recover, we'll give him a second." So these are really alarming cases for the anesthesiologists, although people still do well afterwards. They're good revascularization outcomes after off-pump CABG.

Liz: They're not as good as after an on-pump CABG, where the heart is stopped, the bypass pump takes over; the surgeon gets to take as much time sewing stuff as they want to. I will also say that for off-pump CABG you need to come in a little bit better than for an on-pump CABG because you need to be able to handle having very low cardiac output for periods while the surgeon has to manipulate the heart in ways that it's not used to being manipulated. And we actually saw that when we modeled the cognitive trajectory for off-pump CABG recipients. They were cognitively doing better than the older adults who got on-pump surgery or PCI.

Liz: So you can see a little big of wag where their preoperative trajectory was slightly better, and that jives with knowing that these people have to be a little more robust than somebody who's getting an on-pump CABG, because they've got to be able to survive these pretty significant swings in blood pressure necessitated by the surgical positioning of the heart. Unfortunately, we then showed that they dipped below the other groups on average postoperatively.

Eric: Are there any other better... Why else would you choose off-pump? Are there other studies showing benefits from other aspects besides cognitive function, which I guess the study did not show?

Liz: Mike, I think postoperative atrial fibrillation is less common.

Mike: Not certain that might be the case and I really don't know currently how often off-pump is being used, but I think it still is being used, at least occasionally, by some surgeon.

Alex: Yeah, so as we were just talking about, there's this big concern about the cognitive outcomes of bypass surgery. And there were some articles in the New York Times and other news outlets that really blew this up talking about pumphead. Like being on the pump and having cognitive decline afterward. I guess just for our... in simple terms, for our audience, not that our audience is simple, but just give us the headline. Is pumphead a thing? What does your article have to say about that?

Liz: Oh, Alex, I wish I could give you a straight answer. You thought I was just going to give you a yes, no. I'm not. You have to remember that what we've done is model average trajectories, so on average, everybody averaged together, there is no difference between CABG and PCI. But that doesn't mean that some people don't have what we would consider an adverse cognitive outcome from CABG or from PCI, for whatever reason, and so, I'm not going to say that nobody gets pumphead. And pumphead is sort of this amorphous syndrome-y low cognition, subjective memory complaints.

Liz: We call it pumphead, it doesn't necessarily come with a diagnosis that's clearly causal but I think what we've learned in the last few years is that perioperative covert stroke, for example, is relatively common and certainly one of the things people worry about with the bypass pump is embolizing material up to the cerebral vasculature in causing covert stroke. So you could say on average there's no evidence for an average population level public health problem decrement in cognition after bypass surgery.

Liz: But we also did a post-op analysis that show that some people in the CABG group and some people in the PCI group have bad cognitive outcomes after revascularization, for whatever reason. One of those might be perioperative covert stroke and perioperative covert stroke may be more common with a bypass pump or it may be more common if your heart's being twisted around and you embolize little things from your crunchy aorta, from your cardiac disease.

Mike: I would say that in my experience, a certain proportion of patients undergoing open heart surgery, whether it's CABG or valve or whatever, will experience a period of fogginess after the procedure for some period of time. I agree completely with Liz that the genesis of this is not entirely clear, whether it's related to pump or anesthesia taking a long time to wear off or some kind of other insult to the brain. I think that that is a real phenomenon and for most of those individuals, it will resolve over a period of no more than a couple of weeks, two, three weeks, and they'll say, "Yeah, I'm pretty much back to normal. I felt foggy after the procedure." And their family will say they're foggy, but it tends to resolve completely as far as the patients are concerned.

Eric: I got another question. One of my last questions. The article that Alex mentioned earlier that we presented at the AGS updates talk was from Dae Kim looking at TAVRs and functional status after TAVRs. Because we always hear these stories, like people get better after TAVR, everything's great. It's this non-invasive procedure. But Day Chem's article basically looked at this and what he basically found was that post-procedure function is driven by pre-procedure function. So, it actually didn't... This idea that restoring cardiac output significantly improves function may be somewhat unfounded with TAVR. Are we seeing potentially the same thing here, pre-CABG cognitive function determines post-CABG cognitive function?

Liz: Yeah. We did see that people with lower preoperative cognition were more likely to be in the worst categories for cognitive decline after surgery in the post-op analysis. So having preoperative low cognition continues to be demonstrated as a risk factor for postoperative low cognition and yet, it's not quite helpful enough to tell us who's going to have a poor cognitive outcome postoperatively. Not surprisingly, people who have worse cognition pre-op tend to have it worse post-op, but I don't know that that necessarily matches up very well with the people who say, "I am different after surgery."

Liz: There's this sort of subjective, postoperative cognitive change that hasn't been investigated much, really at all, and comparing that to objective cognitive change and to people's preoperative cognition, either measured or subjective, gets a little confusing. And we've mostly been studying objective-measured versus objective-measured. I'm not sure that's always giving the answer that patients are looking for.

Mike: I think it raises an interesting point. I think that, as Eric pointed out in the TAVR population, I suspect the same thing would be true in general and cardiac surgery patients, that preoperative functional abilities are predictive of postoperative functional abilities, regardless of what the procedure is. And so that has led to some interest over recent years in what's called prehab of conditioning prior to the procedure. There is currently a prospective randomized trial in Montreal, it's actually a multi-center trial throughout Canada, looking at a prehab intervention, which involves exercise and nutritional support to see if it will have an impact on functional status after specifically TAVR.

Mike: But that raises the thought that, well, if we can identify that people who have worse cognitive function or lower cognitive abilities or are on a steeper cognitive decline trajectory preoperatively, is there anything that we can do to try to mitigate that effect on the postoperative cognitive decline? And I don't know the answer.

Liz: It's a really important question, though. And certainly, there are people in the anesthesia space studying this. But it's tricky because these are intensive, costly interventions and you really want to be able to identify the people who would benefit. And we don't have a good way to, for example, measure a cognitive trajectory before surgery and say, "Oh, you're on not a very good one. Let's have you do some computer games or something." Or similarly, for function, you can ask some questions, but you can't always drill down, I think, to the people who are going to benefit. And that's certainly a focus. By identifying those people so we can improve this.

Eric: Is it okay if I move on from this article to my last question, unless Alex, you have other questions?

Alex: No, let's move on.

Eric: Okay. I'm going to turn to both Mike and Liz... So we have a lot of generalists on this podcast, people who are working with older adults, people with serious illness. Is there one or two things that you wish people knew, either about geriatric anesthesiology or geriatric cardiology, that we should be incorporating in our own practices? Mike, or if you had a magic wand that you could make a change to one thing, what would you use that magic wand on? Mike, I'm going to turn to you first.

Mike: Well, I would use the magic wand on cardiologists not on...

Eric: What's that magic wand? What's the one thing that you would use on the cardiologists?

Mike: On the cardiologists, I would want them to take a more patient-centered approach and think beyond their cardiovascular disease. The fact that this patient has multiple other issues and their heart disease is perhaps only one of them, and that they need to talk to the patient and get a sense of what's important to the patient in determining what the best course of treatment for the cardiovascular disease would be. The same applies to geriatricians, but it's like preaching to the choir in talking about those things for the geriatricians.

Alex: Although I guess it's caution to the geriatricians, those taking care of older adults, whether a primary care doc or your palliative care doc, that when you're working with a cardiologist to make sure that they're focused, helping them to focus on the bigger goals, aspirations, hopes, dreams, wishes of the patient rather than a single pump or the vasculature.

Mike: I think that the way cardiology is structured, there is a tendency to look at diseases in silos. We have guidelines for each different disease, atrial fibrillation, heart failure and so forth. Follow the guidelines and you're just treating that disease, you're not treating the whole patient. And so, I think that there just needs to be a broader perspective on caring for older individuals who have more than one silo disease.

Eric: Liz, how about you?

Liz: Well, I think that this paper and this analysis is actually really important in understanding average causal impact of major surgery on long-term cognition. Because this is one of the most provocative surgeries for cognitive change that we could think of. And we didn't see that CABG changed your longitudinal cognitive trajectory. There are older adults who don't seek out functional improvement through surgery because they're afraid of the cognitive impact. There's this feeling, this dogma, that surgery and anesthesia are bad for older adults.

Liz: And I don't want that to be what keeps you from getting a knee replacement when you've had functionally impactful osteoarthritis. You're on opioids, you're not sleeping well, you can't exercise or go ballroom dancing with your friends. Talk to a surgeon. If you're an appropriate candidate, there's very little evidence based on this work, that an episode of surgery and anesthesia that goes well, that fixes a problem, is going to change your long-term cognition. And so, leave it up to the people who know you best, and yourself, to understand whether this functional improvement that you're hoping to accrue from surgery balances out the other potential risks, because, on average, there's not a hit to your cognition; for older adults having major surgery.

Alex: And I guess the functional equivalent would be if you're an older adult who gets chest pain when you're walking around but you're trying to avoid surgery because you're afraid of the cognitive outcomes, at least you should go talk to the cardiologist, talk to anesthesiologist, talk to the surgeon and maybe reconsider that in view of this paper.

Liz: Yeah. See if it's the right thing to do.

Eric: Well, Liz and Mike, big thank you for joining on this podcast. Alex, little Bee Gees. And I think you're right, before I get a lot of emails, I think the Bee Gees are from Manchester but...

Alex: Oh, okay.

Alex: (singing)

Eric: I think from now on we're just going to do Bee Gees songs in the future Alex [laughter]. Email all our future podcasts for guests, stick with Bee Gees. Well, Mike and Liz, big thank you for joining us on the GeriPal podcast.

Liz: Thanks so much for the invitation, great to speak to you guys.

Mike: Absolutely, thanks very much, it's been great fun.

Eric: And a big thank you to Archstone Foundation for your continued support and to all of our listeners, thank you for supporting the GeriPal podcast. Goodnight, everybody.

Alex: Goodnight.

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