Podcast Host (2:33)

All right, so diving into our case, we have a 60 year old gentleman in pre op clinic prior to a planned middle ear exploration. He has a past medical history of hypertension and takes amlodipine 10 milligrams and ramipril 10 milligrams daily. Today in the clinic, his blood pressure is 134 over 68 and his recent labs are all normal. So thinking about this patient, how are you approaching the medical preoperative risk stratification and what are you going to tell him about how and when to take his medications prior to surgery?

Dr. Michael Janjigian (3:06)

Great. So just as the big overview, my approach to perioperative medicine is that it's really like a primary care visit. You're ultimately going to evaluate the patient for all of their comorbidities, you're going to try to risk stratify each of those comorbidities and you're going to address all of those in your assessment and plan. And you're also going to address every single medication that they're on and advise the patient about what to take and not to take in the perioperative setting, specifically on the day of surgery. But really every patient gets a cardiac clearance. I mean, we don't love to use the word clearance, but that's really ultimately what the surgeons want out of us. They want to make sure that we say the patient is okay to go to the operating room. And really the foundation for that is a cardiac evaluation. Every patient, no matter what medical complications they have, is going to get a cardiac clearance. So really the backbone of this is going to be the ACCAHA guidelines. And so the timing for this podcast is good because they just updated their guidelines in 2024 and the prior iteration was from 2014. And so we can use this as a chance just to go through the algorithm so that you can apply this to really any patient that you're going to see. So my approach to the algorithm is really to do this as a stepwise approach. I really try to think of this in a really rigorous manner and I think this can help learners to really understand the approach better. But before we even get to step one, it helps me to think of what is the end point of the algorithm. We're doing a cardiac clearance right now. So keeping in mind that if you get all the way to the end of the algorithm, you may be recommending the patient for a stress test. Or even a left heart catheterization. And is there going to be benefit to that? And if that's ultimately where we end up in this algorithm. So keep that in mind as we're going through these steps is like the ultimate destination may be further cardiac imaging or even intervention. So step one, does this patient even need a pre op? Right. So this is an important consideration. If you're a surgeon in clinic and maybe you're clearing them for middle ear exploration or a total hip arthroplasty, you need to decide whether that patient needs to see an internist before surgery or not. And not every patient requires it. So for example, at Bellevue Hospital, if you meet any of the criteria, which is an age cutoff or certain comorbidities, any health system will have certain criteria. If you don't meet any of those criteria, these patients just go straight to surgery. They actually can bypass the pre op testing altogether and then anesthesia will see them on the day of surgery. So really the first question is, does the patient have risk factors and need to even be evaluated by an internist? If you, if we do need to worry about it, if they meet any of the criteria, then we proceed down the algorithm. So the next question is, is the surgery emergent? Usually we define that as loss of life or limb within two hours if they don't go to the operating room, things that could wait a day or two, like if there's a hip fracture, you want them to go as soon as possible. We don't consider those emergent, even though we want those patients to go as soon as possible. So obviously you're not going to do a stress test or a heart catheterization or on someone with a ruptured viscous, somebody who needs to go to the OR within two hours. So the first question, is the surgery emergent or not? So if it's not emergent, we go to the next step and this is where we consider active cardiac conditions. So does the patient have acs, acute coronary syndrome, an unstable arrhythmia, or decompensated heart failure? So these things may be obvious, they may not. I'm thinking now from the inpatient setting, maybe there's a trauma, maybe they had a traumatic fracture and you need to worry about, is there a troponin spill, are there some crackles, is there something subtle as a result of the reason that they're in the hospital in the first place? In clinic, you're assessing these patients for symptoms. Maybe they don't see the doctor regularly. And this is really the first time they've seen an internist and they're finally able to describe some of their worries and symptoms to you. So if you're not worried about any of those things, acs, arrhythmias or heart failure, they. Then you can continue down the algorithm. If they do have any of those things, you pause, you address them, and then maybe you're going to delay surgery or medically optimize them before. All right, so the next step is going to be estimation of perioperative risk. There are so many different risk tools out there, so if you actually reviewed this, your head would kind of spin with all the options. The ACCAH algorithm is nice. They really just recommend two. And even from 2014, it hasn't really even changed to 2024. There's two tools that we're using to risk stratify people. The first one is the RCRI score, the revised cardiac risk index that's based off prior models. It's been around forever. Almost everybody knows that. It's like, I think of it like the Latin of risk stratification tools. It's been around forever, but it's becoming less and less useful. So it's still in the guidelines, it's still worth knowing about. I still teach it. But mostly we're going to use the second tool, which is the Gupta score. So Gupta is the lead author on this paper. It's also called the MICA score, the MI cardiac arrest score, because that is the main outcome. They're looking at it, so the name is a little bit cleaner as well, and so is the tool itself. So with the Gupta score and for the RCRI score as well, you can just go online and plug these things into md, CALC or whatever other tool you want to use. The score we're looking for is a risk of 1% for cardiac outcomes for major adverse cardiac events, or MACE. If the risk is considered less than 1%, then they're considered low cardiac risk. And usually that means you can proceed to the OR. And if the risk is greater than 1%, then we need to do more determination. So in this case, the Gupta score is nice because it just gives you the score right there. The RCRI score, we say a score of 0 or 1 is considered low risk, or 2 or greater is elevated risk. So are CRI 2 or greater or Gupta score greater than 1%? We're going to continue down the algorithm. What is different about the 2024 algorithm compared to Prior is that we're now thinking about chronic disease risk modifiers before, it was just implicit that if a patient had some serious comorbidity, then it was supposed to be, like, obvious that you had to pause and think about it. But now they've just put it right into the algorithm itself. So we're going to think about chronic disease risk modifiers. I'm not going to go through all of them, but they list things like severe valvular heart disease, severe pulmonary hypertension, congenital heart disease, things like that. So you can look at the algorithm for the full list, but you're going to pause if there's any of those things, and then you're going to ask for help if they do help from.

Podcast Host (9:33)

A specialist, their cardiologist and so on.

Dr. Michael Janjigian (9:35)

Yeah, exactly. So, for example, and we've tried to establish these rules here as well, but if they have, say, pulmonary hypertension is a great example. If it's type 2 or caused by cardiac causes, you would call it cardiology and they would assess. But if it's primary pulmonary hypertension, which is typically managed by pulmonologists, then we would call pulmonary and they would help manage that patient. So depending on what the situation is for the patient, you're going to call the correct service. All right, so now that we've gone this far into the algorithm, now we're at a decision point where there's three different ways we could go. So let's start with the patient at low cardiac risk by RCRI or Gupta and none of these chronic disease risk modifiers, those patients can now proceed to surgery. We're basically done. We can address all their medications and other comorbidities besides cardiac. But from a cardiac perspective, you don't need to proceed any further. The next of the three would be if they have a chronic disease risk modifier, then just as we spoke about, you need to address that. Then the third category will be if they are at elevated cardiac risk. So an RCRI of 2 or greater, or a Gupta score of greater than 1% without chronic disease risk modifiers. Now, we're going to keep moving down the algorithm at this point. It's at this point where we need more information. Typically, the next step is going to be what is their functional status. This is also same from what it was in the 2014 guidelines for functional status. We're using what are called metabolic equivalents. That's essentially like a 75 kilogram man sitting at rest is like one met historically. So there's some studies that have looked at this and they've used different cutoffs. But what we've essentially concluded is that if you can do more than 4 METs, your overall cardiovascular risk is considered acceptable to go to the or, regardless of what your Gupta score or RCRI was. So it's a very positive clinical finding if you can do more than 4 meds. So what is 4 meds? Typically, we define that as being able to walk two city streets or a flight of stairs at a normal pace. So we live in New York. It's much easier. Everybody walks everywhere. They're taking the stairs, they're running for the bus, they're going up and down subway stairs. When you get to communities where everybody's driving everywhere, it's probably going to be a little bit harder to determine their functional status. But we say two city streets at a normal pace or a flight of stairs at a normal pace. If they can do that, you keep moving. Otherwise, we are moving down the algorithm.

Podcast Host (12:07)

Just to clarify, if they can do that, then proceed with surgery, but if not, then you continue is what you're saying.

Dr. Michael Janjigian (12:13)

So if you can't quite do 4 Mets, regardless of whether it's because you are in a wheelchair or you have paralysis for some other reason, or perhaps you have claudication or there's some other medical reason preventing you from doing the four Mets, if you can't do the formats, we're going to continue down the algorithm. But if you can do the formats, even if your cardiac risk is elevated by the risk tools that we used earlier, if you can do more than four METs, you can proceed to surgery at this point. But let's say we've now reached this point, your elevated cardiac risk without chronic disease risk modifiers. But you cannot do four MEPs. This is where things get murky, and this is always the hardest part of the algorithm at this point. The way they word this in the algorithm is, will further testing impact decision making or perioperative care? So sometimes you have to think about, again, the end result is, are we going to do a stress test, Are we going to do a left heart cath? If there's disease there, are we going to stent somebody and put them on dual antiplatelet therapy? Right. You really have to think a few steps ahead. So maybe this is a patient with bad cancer and then the cancer just needs to come out and you can't wait for all of this other testing to be done. Or perhaps it's a hip fracture and they really would benefit from having the surgery done sooner rather than later. Sometimes these patients will try to usher in sooner and not think about further testing at this point in the algorithm. But that being said, this new 2024 algorithm has added a new section there that wasn't there previously that the Canadians were doing, that we've now adopted, which is checking bnp. So historically, my teaching was I would add it, I would kind of take the best from the Canadian algorithm and the best from the American AHA ACC algorithm and I would add the BNP at this point. But now in 2024, the ACC has added this as well. So not to get into all the details of the studies, but what they found is a very low BNP or pro BNP puts you at a relatively low cardiac risk. Now, there's so many studies on this with different cutoffs, it's hard to quote exact numbers, but with a very low BNP or pro BNP. And here we use 300 as a cutoff. Other studies have used 200, but this algorithm uses 300 for pro BNP as a cutoff. But below that value at this point in the algorithm, you can proceed to surgery. So that's great because we can just very easily check that lab value. Sometimes it's checked before you even get consulted. But at this point, it's much easier to order this BNP or pro BNP than to recommend a stress test, which is what we used to have to do.

Podcast Host (14:41)

If someone had a BNP checked, let's say six months, a year ago, and you're looking back in their chart, are you going to trust that or does it really depend on what their BNP is, you know, the week prior, the day prior?

Dr. Michael Janjigian (14:53)

Right. That's a great question. So when I'm on inpatient, there's very dynamic their disease processes and what might be going on. Or maybe they did come in as a hip fracture or trauma or something like that. So I'm going to want something from that hospitalization.

Podcast Host (15:06)

Right. Makes sense.

Dr. Michael Janjigian (15:07)

If you're in clinic and the patient seems very stable, you know, you're going to have a little bit more wiggle room on how you know all that BNP could be before you act on it. Six months might be a long time. You might want something a little bit sooner than that. I don't think there's exact cutoffs for that, but I think within reason you could use a number within a few months if there's really no clinical change. So we're now we're at the point in the algorithm, or let's say you're at elevated cardiac risk, you have fewer than four METs that you're able to do, and your BNP or pro BNP rather is greater than 300. So where we're moving now is the wording in the algorithm is multidisciplinary team discussion regarding risks and benefits of additional cardiac evaluation. So this is again, a little bit murky. They're not pushing you to get a stress test in this case, right? Which is, I think the reflex in a lot of pre op clinics or just private clinics around the country, they're trying to push you away from stress testing this whole point of this algorithm. But at this point, you have to consider it. So the things that they are recommending you to consider at this point is transthoracic echocardiogram, right. The TTE consider non invasive stress testing or consider a coronary cta. They don't really push you in one direction or the other. I can tell you our anesthesiologists and they're really our audience for these notes, the surgeons want that checkbox checked that the patient is quote, unquote cleared for surgery. But ultimately it's the doctors on the other side of the drape that are going to be the ones managing the patient in the orientation. And they want to know what the ventricular function is. If the blood pressure drops, can they give fluids? Like what are they doing with preload, what are they doing with afterload? So most anesthesiologists appreciate it when you get an echo in these kind of more hazy clinical situations. Stress testing, I would say the ACCAH guidelines don't really push you away from it, but it's a 2B level of recommendation. So it's one of those like is reasonable to obtain. The Canadian guidelines really push you away from stress testing in that situation. And the coronary CTA is becoming more and more common. But also in these guidelines, it's a 2B level of recommendation at this point. So there's nothing really if you've made it to this point in the algorithm where you have clear guidance on what to do next. So if you do those testing and they are, they're reassuring, then you can proceed to surgery at that point. Say you do a stress test or one of those other things and it looks like maybe they have ischemic heart disease, right? They're not even at this point telling you do a left heart cath, even at this point with a positive stress. Say they're saying consider alternative strategies, deferral of surgery, non invasive or invasive treatment or palliation, or proceed to surgery. So say there's a stress test with some ischemic findings. It's really up to you at this point whether you want to refer them for left heart cath or not. There is data looking at this question and mostly it does not favor doing left heart caths in patients just to try to decrease their perioperative risk. So the rule of thumb typically is if you're thinking about a stress test, if you're thinking about a left heart cath, do them if you would have done them even if they weren't going for surgery. So maybe somebody shows up for an elective surgery and you know, the first time they've had a good review of systems and you're getting out of them that they have an angina history or some other concerning symptoms that is not that unusual. So it's in these situations that sometimes we pause and we say like, look, it doesn't even matter that they're going for surgery. And we would have done this regardless.

Podcast Host (18:37)

Yeah, it makes sense that this algorithm would kind of serve to capture patients whose first encounter with the healthcare system in many years is for their pre op appointment. A lot of this will end up being, of course, multidisciplinary discussion, but also patient doctor discussion and, you know, seeing how the patient feels about all this testing.

Dr. Michael Janjigian (18:57)

Absolutely. When we get to this point in the algorithm, we have really in depth discussions about what to do. Often we're asking colleagues for advice or even asking cardiology or other specialty services services. We really do have interdisciplinary approaches. And the other key stakeholders here is to call anesthesia and to also call your surgical team, because it's not even always clear to us how involved the surgery is, how many hours it's going to be, fluid shifts and things like that. So when we get to this part of the algorithm, we really are picking up the phone and we're calling our colleagues and we're talking to our patient to involve them also for shared decision making, to let them know about what we perceive the risks to be and what the options are for further workup and risk stratification.

Podcast Host (19:39)

Getting back to our patient, just as a reminder, he is 60 years old, being seen prior to a planned middle ear exploration, and he has a history of hypertension on two medications with a good functional status. This is not an emergent surgery. He does not have any evidence of unstable cardiac disease and he has no chronic disease modifying risk factors. So going through the algorithm, we see that his Gupta score is calculated at 0.1%, which is less than 1%. And so he's at low cardiac risk, which means that happily we can tell him he can proceed to surgery. He asks you, okay, great, but what do I do about my meds? Do I take them the morning of the night before?

Dr. Michael Janjigian (20:18)

Right, so this is a great point. So we're not done yet, Right? We've done his cardiac risk assessment. And so from the medication perspective, we can just do one more quick teaching point here. Antihypertensives are a class of medication that we come across very frequently, both inpatient and outpatient. And so this patient was on a calcium channel blocker and an arb. And so calcium channel blockers have been shown to be very safe around the time of surgery. I mean, our goal is really to avoid hypertension and hypotension. Continuing calcium channel blockers has been shown to be very safe. So that's a pretty easy one. We continue. The calcium channel blocker, angiotensin receptor blockers and ACE inhibitors have been shown to cause hypotension with anesthesia induction. So there is always this question about what to do with those patients. Now, when they've studied this, patients do get hypotensive, but they have not found that patients have clinical complications as a result, such as MIS strokes or acute kidney injury. And there have been a few studies looking at this. And so ultimately there is still some equipoise here, but the recommendations are, for most patients who have chronic hypertension, it's okay to continue it, but if there's a concern, perhaps the patient's going for major surgery and they're gonna be under anesthesia for a while. And in some of those patients, it's reasonable to hold the ARB on the day of surgery. Other considerations are if they're on in the ACE or ARB for neurohormonal benefit for patients with heart failure. Those patients are also, we try to recommend continuing the ACE or ARB because there's that other degree of benefit for those patients. So for this patient, because he had well controlled hypertension and this was not considered a major surgery, it was recommended that he continued both of those antihypertensives throughout the perioperative period, including on the morning of surgery.

Podcast Host (22:03)

He's very happy to hear that he doesn't need to make any adjustments to his plan. He has the surgery, everything goes smoothly, and he thanks you very much for your care. Thank you so much, Dr. Janjaygan, for taking us through this case. I think this was a really nice way to kind of explore the recent guidelines and use them in practice. And we would love to see you back here on run the list thank you so much.

Dr. Michael Janjigian (22:25)

It was a real pleasure. Some content from this episode was generated with the assistance of artificial intelligence.