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Clinical Editor's Corner Live: The Langston Catheter, Team Functioning, and a Critical Left Main Case
Join Drs Kern and Lim in this 40-minute discussion of:
• The Langston Catheter's return (start to minute 13:44);
• Cath lab team optimal communication and functioning (minute 13:45 to 28:00);
• A difficult case of a critical left main stenosis in a 72-year-old male (minute 28:00 to end).
A transcript is available below.
Watch More From Dr. Kern:
Effective Followership: What It is and Why It’s Important
Hemodynamic Rounds Live: RA and LV Waveforms
Hemodynamic Rounds Live: The Regurgitant Aortic Valve
Conversations in Cardiology: Futility in Patients With STEMI – Do All for All?
This transcript has been lightly edited.
Morton Kern, MD:
Welcome. This is Mort Kern. I'm hosting the session on Cath Lab Digest live with my colleague and friend Mike Lim today. And we're going to cover a couple of wide-ranging discussion topics, but they'll be headed up by the last two issues of the editor's page in Cath Lab Digest that I put together. We're going to talk about aortic stenosis today. We're going to talk about the Langston catheter (Teleflex). We're going to talk about team membership, followership, and what comprises a good lab interaction. And then lastly, I have a unique case I want to show Mike Lim. He's going to comment on management of critical left main in a site that does PCI without onsite surgery. So, Mike, welcome. Thanks for joining me today.
Michael J. Lim, MD:
Thanks, Mort. It's always a pleasure to have a robust discussion with the renowned Morton Kern.
Morton Kern, MD:
Oh, you're too flattering. Okay. So I think this should be fun, hopefully fun for the listeners as well, as fun for us and educational on top of that. So, I'm going to just start us down the images that I brought. So, November of this year, we wrote an editor's page that the Langston catheter had come back into play after a year and a half of absence. And at TCT we did a live session. And I think it's really a testament to the industry on helping us get good care delivered to our patients. So, in the absence of the Langston catheter, we had another editor's page on all alternatives, all the different things you could do. I know that many people struggled, but often they did workarounds. Mike, let me just mention this, we have the Langston, we use it, I think everybody likes it, it's effective, it's inexpensive relative to the other techniques and highly accurate. So, it's on my list of good things. What was your go-to work around when you didn't have your Langston, Mike?
Michael J. Lim, MD:
Well, mine is maybe different than most of my colleagues or other people that I talked to. Let's start with the latter. Transcatheter aortic valve replacement (TAVR) and aortic stenosis has been exponentially growing, and on our minds and in our cath labs significantly over the past decade now. In performing TAVR in the early days, we measured gradients invasively on all these patients. More and more frequently these days, that has gone by the wayside. We are using echocardiography almost exclusively for hemodynamic assessment. With the Langston coming off the market, that became more frequent on the workup, with utilization of just echocardiographic data and clinical data to determine whether somebody had a TAVR or surgical aortic valve replacement need, or was put in the watchful waiting category.
Now, my issue with that is, as you and I come from a strong invasive hemodynamic background, there's times where the clinical scenario and the echocardiographic data are in juxtaposition. They don't agree. There are times when we have this low-flow, low-gradient state that we need to better understand. You need to have an invasive way to determine this. So, my favorite was actually using a guiding catheter and a pressure wire. The pressure wire being in the left ventricle and the guiding catheter, most of the time it was a multipurpose, occasionally it was a Judkins right (JR)4 and Amplatz left (AL) in the ascending aorta. The pressure wire itself gave a high-fidelity signal of the left ventricular pressure tracing and the guiding catheter gave us an ascending aortic pressure, where we didn't have a timing issue and all the other things that we can talk about that give falsities to invasive measurements. But that was my go-to.
Morton Kern, MD:
I think it's important. First, we can now, in cases of discrepancy between echo and clinical data, go back to hemodynamics, which was our original standard. Second, we should recognize that there's a hierarchy of accuracy of techniques and a variety of ways to do it. I listed on this editor's page on Table 1, all what I thought were the key features of measurements. Now, what I also thought was good, and I advance my slides here, I just want to show you a picture. Of course we have the Langston itself right here, the Langston catheter. It's quite remarkable and it's been a good product for a long time.
Michael J. Lim, MD:
While you're there, Mort, just to remind folks, this dual lumen catheter was designed to measure pressures. The second lumen was never made to inject through, especially, with a power injector. And, it was the use of the power injector through this catheter to do ventriculography that led to it being taken off the market, because it caused damage to the catheter, which it wasn't designed for. It was a hemodynamic catheter, and it's still great even in its new modifications for hemodynamic measurements.
Morton Kern, MD:
That's very interesting, because I don't believe it was common knowledge that this was only for pressure, because I've probably done a ventriculogram through it — maybe you have. I know many who have, and we weren't concerned about it. But the issue of the 10 out of 20,000 uses having a fracture or rupture, that's a very small number, the company addressed it, I thought, very fast and accurately. It was a function of the acrylic glue that they used, they managed it well, and now it's back. Let me show you a couple other things that we talked about which are equally important. Here we have the factors that go into good hemodynamics no matter what system you're using. And, on the left is a transducer. In the middle are our cables that hook up the transducer, the electrical signal that converted the mechanical to electrical, electrical transmitting it into our recorder. All three points in this sequence can be a source of error. I know all of our labs have this potential for this problem.
When we think about good fidelity, we want a good hookup, we want good connections, and we want good recording. I'm just going to stop there. There are more details in the editor’s page. Here's what I wanted to show the readers again, because you touched on this nicely. These are the catheter techniques used to measure gradients.
On the left is the highest fidelity, highest accuracy. On the right is the lowest fidelity, lowest accuracy, and in between, a decreasing fidelity and accuracy. On the left is the Millar high fidelity dual lumen catheter, solid state, it's the gold standard of all hemodynamics. In the middle there, on the left, you see an aortic stenosis measured with the Langston. And then, next to that is the old method of pigtail through a femoral sheath. You can see I outlined the red, which would be the femoral sheath pressure. And compared to the true aortic pressure, it's higher and delayed. Lastly, is the pullback, the single left ventricular (LV) catheter pullback. It was interesting to me that when I asked the audience at TCT for their favorite technique for aortic stenosis assessment, what do you think they said?
Michael J. Lim, MD:
The one on the right.
Morton Kern, MD:
The one on the far right. The single catheter pullback. The least accurate, least fidelity, but that's what they're using to tell you how much aortic stenosis. I wasn't shocked exactly, but it was unfortunate that I think there are so many better ways to do this. And yet, my colleagues, maybe they were my contemporaries, chose this one. Anyway, my fellows won't choose this one. What are you teaching them in your lab, Mike?
Michael J. Lim, MD:
What we're teaching is not necessarily what's in practice, right? Human nature, not just interventional cardiologists or cardiologists in general, I think we're very slow to change. If we go back to the days in which heart catheterization was the be all, end all, meaning before Harvey Feigenbaum and others showed that noninvasive echocardiographic hemodynamics were something that was highly accurate and reproducible, what we did on the right in terms of pullback was exactly what we did in every case, and it's just become this cornerstone of what's done. When you do it in the cath lab over and over again, it's hard to get rid of. You just get used to the certain patterns.
The other thing I would suggest is that it is hard to tell how inaccurate the femoral artery tracing versus LV tracing is compared to the pullback. In that femoral artery versus aortic pressure tracing curve, as you're looking at it, you see two problems with the femoral artery pressure tracing. One is the time delay between the upstroke of the femoral pressure and the left ventricular pressure, taking advantage of the fact that it takes time for blood to come through the ascending aorta, down the descending aorta, into the abdomen, and down to the femoral artery. That time delay is problematic. Second, you look at the actual elevation of the femoral artery pressure over the aortic pressure, that pulse amplification problem that exists. The average person who's taking care of a lot of patients in the catheterization lab these days, they don't want to think about any of this. They like dichotomy, they like replace the valve/don't replace the valve, stent the artery/don't stent the artery. This is, again, just basically to say, human nature. So, we can have great classroom discussions, we can have great teachings, and we can write chapters and textbooks and review articles on the time delay, the pulse amplification, how you can correct the time delay electronically, but that doesn't correct the actual accuracy of the gradient and all that. At the end of the day, I think clinicians are looking for yes/no answers and that's why they're totally fine with pullbacks and femoral artery, left ventricular pressure tracings.
Morton Kern, MD:
Mike, unfortunately, I agree with you that the cardiologists, many of the invasive guys and interventionalists, want a dichotomous life. But, the truth is we don't live in a dichotomous world and the patients are not dichotomous. They have a lot of variation and they pay us a lot of money to make those good decisions. So it makes me unhappy that I would have a cardiologist who would settle for a dichotomous answer without enough strong data to go one way or the other. We've seen it in the fractional flow reserve (FFR) world; we've seen it all over the place. I said to the Cardiometrics company years and years ago when they had a Doppler wire, "What we want is a green light and a red light. I don't care about any of the numbers. Just show me a green light if I go, or a red light if I stop." And of course they laughed. I was serious. But, we need numbers to make the lights green or red. And it's in the acquisition of the numbers that the dilemma really comes. But you are correct. I have hoped that my colleagues have read some of this stuff, or people in the lab have read this and they like to get higher accuracy and better care. That was the bottom line for the whole editor’s page: better care.
Michael J. Lim, MD:
The purpose and the concept of what we're bringing up is, once this catheter reaches a sufficient stockpile of production, it will be able to be in the hands of invasive and interventional cardiologists again. It is going to be the easy, preferred way to get the most accurate hemodynamic assessment of an aortic valve.
Morton Kern, MD:
Yes.
Michael J. Lim, MD:
Because you can measure the left ventricular pressure and ascending aortic pressure simultaneously, no time delays, no pulse implication, and what have you. As long as you get all your wires connected like you showed in the last slide in the proper way, and you don't have air bubbles and have the proper fidelity of your signals, you can get a simplistic, accurate answer.
Morton Kern, MD:
True. Bottom line, accuracy counts. I'm going to shift gears on us now and move to the next topic, which was our editor's page on effective followership in the December Cath Lab Digest. This is somewhat obscure to most people. Effective followership means, "What team member are you? And, why do I care what team I have?" The answer to those questions is, "I care what team I have, because it impacts patient safety directly." That is, "A weak team, or a bad team, or a team that doesn't communicate can be associated with harm and poor outcomes." Teams are made of people, all kinds. It's important to highlight what makes up a good team.
Effective followership came from a safety talk that we in our lab were asked to participate in. Our lab then joined a series of interactions with a facilitator to talk about safety. Safety means, a team that's present in the lab both mentally and physically, one where we have a understanding of our common goals, that we are committed to what we're doing, that we have checklists, timeouts, that our roles are clearly defined, our communications are structured, functional, and clear. And, that concerns and comments when something's not working can be addressed. We talked about that. I probably wrote more than I should have on this topic. But, it covered a couple of things which I think are worth talking about. One of the issues was the types of people that work in the lab.
I thought this was interesting. It wasn't meant as criticism, it just meant as an observation and that we should be able to help our colleagues. What we would like to have in the lab is everybody in the game, everybody thinking about the same thing, having situational awareness, having clear, closed loop communications, being involved. That requires independent and critical thinking. I can't tell you what will be coming next, because you should already be thinking about it like I am. That person is living in the upper right corner. The independent critical thinker, he's effective, he's following, he's leading, he's setting an example, he's communicating with the attending, the attending's communicating back, people are following along.
Now, compare that individual to some of the others. So you have another smart person, independent thinker, but this one's not involved, alienated, it's a blue face, up in the upper left. You have to get them engaged. They're not helpful if they're not engaged. They may know that something's wrong, they don't want to say anything. I think that is a real serious problem. On the lower left, you have that person standing in the lab, they're not even sure what they're doing here today, but you want to engage them, and then help them think about what their job is.
The one on the far right, lower, he's a dependent thinker. He wants you to think he's in the game. He's not. He's echoing back something he heard a minute ago. He doesn't actually understand what's happening. But he's smiling, he's there, but he's totally unhelpful. And, we have to devote time as leaders and as actually coworkers to our colleagues who are in one of these groups other than the upper right quadrant.
Mike, you took on a really big job in Hackensack [New Jersey]. I'm sure that a lab that does, I don't know, a thousand percutaneous coronary interventions (PCIs) a year had a lot of people, some of which fell into one of these four categories. How did you manage such a large group like this? Or what did you do to assist in building a better team?
Michael J. Lim, MD:
This is a great thinking tool you put forward. That's the point of your editor's page, to get people to think. We would like for everybody within our lab environment to view themselves as a leader and maybe not as a follower. But everybody has times during the course of the day and a role, where sometimes you are following and other times you're leading. That's one point. Second, there are certainly going to be a handful or a small percentage of people that you work with that are in that upper right, effective corner. But the majority of the people that you have working in your lab are going to be in the other three quadrants. The idea is to try to figure out what it is that puts them in that quadrant. Meaning, is that where they live or are there other reasons why they're in that quadrant? If there's other reasons why they're in that quadrant, how can you help move them? How can you elevate their status? Your guy in the blue, the alienated guy who is an independent critical thinker, but more passive. Are they more passive because they're not given an opportunity to be active, because they've been shut down? [Perhaps] they've offered opinions and they've been chastised for that. So they reverted into a saying, "Well, that's not my role anymore. I'm just not going to do that." You need to figure out how to try to help them learn to pick and choose. Some operators want their opinions, other operators aren't necessarily going to want their opinions. But, the operators that want their opinions can gain significant value from that.
People who are unconscious, sometimes they're unconscious because that's what they choose to do. We have a lot of rules and regulations within our labs right now where we punch in and punch out on a time clock. We're doing the hours. You mentioned timeouts and other things. There's a lot of check boxes. You can go through and be just fine working in a cath lab just checking a bunch of boxes. If there's no value that this person sees in doing more than just checking boxes, they're going to remain unconscious. It's up to a good leader to try to figure out, "Hmm, what's valuable to this person. How can I potentially get this person to raise their level of consciousness and to exercise some things that they're not exercising now, like their mind?"
Then, the unhelpful person who's smiling and just the “yes” person that you talked about, that doesn't necessarily do the noncritical thinking piece, why aren't they critically thinking? Do they have a lack of knowledge and they just don't want to speak up, they don't want to stand out or do they have other issues? My takeaway from this is to try to figure out in each individual person where they fit and what it is that you can help them with to try to elevate their standing.
Morton Kern, MD:
The last word on this for me is, all of us are leaders and all of us are followers, and we'll take different roles at different times, but we should all try and remain in that upper right quadrant. I want to just highlight something else we learned at this little session on safety. Safety in the cath lab is number one. We have checklists, we check the patient, we check our meds, we use closed loop communication. The more of that you do, the better the safety record, the lower incidents of harm.
One thing that is hard to do sometimes and in the airline industry, the co-pilot has to check with the pilot to make sure when he feels something is wrong, "Pilot, I feel something is wrong. Can you check it for me?" The airline safety industry is riddled with examples of a pilot doing something he shouldn't do and nobody challenging him. They didn't take action, they didn't engage him in the 3Ws, or the 4-step tool, or the team, or even go to the chain of command, they just accepted it quietly and it caused disaster. Because if you make a mistake flying an airplane, bad things happen.
I thought this was helpful. Our lab has a standing timeout. Anybody can call a two-minute stop. Stop the line, the nurse can say, "I need a minute to get this organized." Or, "I don't like what I see." Or, "Can you explain that to me one more time? I'm not happy with what's happening." When you hear that, our response is to stop, find out what's causing their concern, and then address it. So, the way that it often comes up and a nice, easy way for somebody to say, "I have a concern," is they say, "Dr. Mike, I see an arrhythmia on the screen. What I'm concerned about is that this arrhythmia is going to cause hypotension or a cardiac arrest. And what I want is for you to address it. Can you help me out here?" You don't do anything. She says again, "Dr. Mike Lim, I am uncomfortable with seeing V-tach on the monitor. I think you should move your catheter or give a drug. Would you like me to help you move your catheter or give a drug?"
So that would be the 4-step second escalation. If that doesn't work, she would say to her team, "Team, do you see this V-tach? Dr. Lim doesn't want to do a thing about it. Is that right?" And the team would say, "No, no, no. Mike, do something." And finally, she'd say, "Okay, Mike, you're not doing it. I'm calling your boss. I'm going to get Mort Kern in here, and he's going to come in, and we're going to have a little meeting." But it better go quick, because this guy's in V-tach. So, these are the ways you escalate.
But, that green box, that green circle there is at any time there is critical safety at hand, everybody should be interested in taking an action. If my fellow is doing something and I say to him, "Hey, I'm concerned about your catheter position." And he doesn't do anything, I'm going to reach over and I'm going to move the catheter. Or, if I'm doing something and my tech says to me, "Hey, you better watch that wire. It's not in the right place. Hey, hey, hey." He can reach over, touch my hand, or move the wire if he has to. If it's going to be evident harm. I thought this was pretty interesting. It's a little formalized, but when my team says, "Hey, I don't like that." Boom, my antennae go up, and I'm going to pay attention. That's what I want to teach the fellows as well. You're not here by yourself. This is a team sport. When they say something, they have experience, they're talking to you, and you don't have experience enough. So, pay attention. I'm sure you've had this.
Michael J. Lim, MD:
Yeah, I think this is critical. This is a piece that's transformational and undergoing active change in all the labs in our country right now. Because in the "old days," which I think still occur in many labs in this country, even right now as we speak, the chain of command is exceptionally simple. The doctor is the boss and everybody else works for the doctor. I think that's not what you're trying to highlight here. I think the key is that the culture has to be inclusive of everybody in the lab. We need to promote and highlight those doctors that work in cath labs that give their team members the opportunity to play critical roles in engaging other people, to promote safety, to offer suggestions, to improve how we do things. That cultural change does not take away from the autonomy of the physician; it enhances the physician. The more we can get that done, the safer our cath labs are going to be across this country and the better off our patients are going to be.
Morton Kern, MD:
Thank you. I agree completely. I think this is a really important asset. I prided myself on being able to build good teams in the cath lab, but some days, some years, it's a challenge. Part of this discussion was that the life of a cath lab is never a constant. That is, you may have a strong lab team this year and next year, but then somebody moves, somebody comes in, the administration says, "Oh no, we can't give you any more money to do that." It's an organic system that changes over time. We have to be continuous. Yesterday for the first time, for team building to our fellow, he's been working in the lab now for two weeks, I said, "Who's your monitor tech?" He says, "What?" I said, "What's the name of your monitor tech? She's on the machine recording us." I said, "Look, we are a team. You need to know everybody's name. You need to use it when you're talking or giving a request, an order. Say, 'Betty, give it now, please, IV dose, 0.5 milligrams.'" Whatever you have. And Betty will respond back. Or, "I'm going up with our catheters. We're putting up a Judkins." You have to address the monitor tech by name so they know what we're doing. Part of this is feedback. That way they don't become concerned. They don't need to yell at attention, they don't need to gauge the team and so on.
Mike, I got a case for us. You ready?
Michael J. Lim, MD:
Let's talk.
Morton Kern, MD:
Okay, let's talk. This happened last week. We're in the cath lab. This is a 72-year-old senior man. He has risk factors of coronary artery disease. He had exertional angina, typical, over the last two or three months. He underwent a stress test and it was EKG positive. They didn't do a nuclear stress because he was at the VA hospital here. His resting EKG is pretty unremarkable. No prior evidence of infarct. He had multiple risk factors. He gets angina when he walks a block or two blocks, but he doesn't get it at rest, he doesn't get it at night, and he hasn't had it in two weeks before coming to the cath lab. We did our angiogram here and the first shot in the right anterior oblique (RAO) caudal is shown on the left. The RAO cranial is shown on the right. So, for those who aren't familiar with looking at angiograms, Mike, you want to just tell us what we're looking at?
Michael J. Lim, MD:
Well, if we look at the picture on the left, as you see the contrast fill in, you're going to see a significant ulcerated stenosis in the distal left main, which the vessel starts out as a wide caliber and quickly narrows down to a very small caliber before it bifurcates into the left anterior descending (LAD) and circumflex. This is why you and I both take the RAO caudal as our first projection, because this is what we're looking for. We're looking for left main disease because when we don't recognize that in a diagnostic angiogram, sometimes that's when bad things happen. This is critical left main disease. And we can get into some of the other nuances of what else you can see, which is a lesion within the circumflex, three-vessel coronary disease.
I think you and I have talked before about, "Do you need any additional pictures?" Well, the answer is no. Your job in taking these pictures I think as a diagnostician is to highlight the areas of problem. The consideration is, this patient may need to get bypass surgery as the best treatment for them. So, can you outline the bypass targets? And, most importantly, do no harm? When we inject contrast within the coronary vessels, we actually deplete the coronary vessels for a short period of time of red blood cells and oxygen supply, and we can create transient ischemia, which in this degree of coronary artery disease, can be problematic. Taking too many pictures in short order can actually cause problems. We don't want to do harm. So that would be my interpretation of what we found here.
Morton Kern, MD:
Okay.
Michael J. Lim, MD:
The picture on the right just confirms that, right?
Morton Kern, MD:
Exactly right. Two things. One is, I didn't expect to find left main, but you should always start looking for it. That was correct. I had a hint of it in our seating injection, so we swung to quick RAO caudal. You see that right coronary artery is totally occluded. There's a lesion in the circumflex. And, what I liked least about this and was most concerned about was this ulcerated image in the distal left main before the bifurcation. That crater has some ominous prognostic information.
Okay, let me show you the right, because the right is occluded. I took a stop frame. That's as much of it as you're going to see. It's totally occluded. Let's talk about the management here. We work in a lab with no onsite surgery.
Michael J. Lim, MD:
Yeah. Well, the adage has always been to never let the sun set on a left main. You were taught that when you were a fellow. I was taught that when I was a fellow.
Morton Kern, MD:
Yeah.
Michael J. Lim, MD:
I still think there's some truth to that. The problem is in 2022, emergent coronary bypass grafting surgery is not what it used to be. Our surgeons are exceptional, but they're much more used to very planned, more elective procedures than they used to be, right?
Morton Kern, MD:
Right.
Michael J. Lim, MD:
So, you don't have surgery onsite. I think the first question is, "Do you do more at your place?" Do you need to actually open up this left main with a balloon and a stent now? That goes into the clinical condition of the patient. You outlined an exceptionally stable patient with stable angina. The patient was not having active chest discomfort or angina. The patient was not having active electrical abnormalities, so no ST changes. The patient was not having hemodynamic compromise. No hypotension or other worrisome signs of heart failure. In the presence of any of those, I think this discussion gets a little bit more challenging. In the absence of those, I think that's the time to remind everybody to take a deep breath and be thankful for all of that.
Morton Kern, MD:
Yeah.
Michael J. Lim, MD:
Because that means, you don't have to do anything right now. And you probably shouldn't.
Morton Kern, MD:
So let me ask you. So here, do I admit him to the hospital or do I send him home? He came in as an outpatient.
Michael J. Lim, MD:
Well, this is one of the conundrums of modern-day medicine. Now that we know this exists, now the burden’s on us. Yes, this existed yesterday. Well, the patient was at home and slept in his own bed last night. Yes, this existed last week, when the patient was walking for two blocks before he got angina. But now that we know this exists, the liability's on us. So no, this patient doesn't go home, doesn't pass go, doesn't collect $200. And needs to see a surgeon. In a place without onsite surgery backup, it depends on how the arrangement is with your surgery referral center. Sometimes places have an opportunity where either a telemedicine consult can be done, or the surgeons come and see the patient. You admit the patient and have them seen either virtually or in person for discussion about what bypass surgery entails. Other places they don't do that and you need to actually transfer the patient to a place where they do that surgery. Those would be the next steps for this stable patient.
Morton Kern, MD:
Right. So, once you see this, you can't un-see this. And, with that knowledge, all of a sudden, you're heightened about should anything happen to him, you're liable. We admitted him. We arranged for a surgery consult. We kept him on heparin for a little while afterward while he was in the hospital. Otherwise, it wasn't clear what we were doing for him. He was to be sent for surgery. But guess what? There are no beds because of the flu crisis, the triple-demic. He spent another two days with us. He was just preparing to sign out when the bed setup went up. I think, because he's so stable, a balloon pump would not be considered. Although, given the ugliness of this lesion, that might be interesting. And, Impella (Abiomed), at this time, is not indicated. Of course, if he had acted up with angina or EKG changes, we would be forced to do high-risk PCI here in our own center. We can do that. We have an Impella. We'd probably take it on. But, this presents a dilemma for sites doing PCI with no surgery onsite. The question is, should we be doing this at all? What do you think, Mike? Maybe we shouldn't do these cases.
Michael J. Lim, MD:
Do you mean the angioplasty part of the case or the diagnostic part of the case?
Morton Kern, MD:
No, the diagnostic part.
Michael J. Lim, MD:
Yeah. So, if you could tell me how to predict this angiogram from patient features, wow, we've really advanced our ability to practice clinical cardiology. Fact of the matter is, we had a great debate when we were writing the stable ischemic heart disease guidelines. They came out in 2012, the debate was going on in 2009, '10, '11, what's the value of a diagnostic angiogram? These pictures you just showed us are the value of a diagnostic angiogram, because it shows a condition that shortens somebody's life expectancy.
Morton Kern, MD:
Yep.
Michael J. Lim, MD:
The only thing as equal value to that in my understanding in 2022, going on 2023, is a computed tomography (CT) angiogram, which would show you the same thing, but a stress test could've missed everything you just saw, because you don't have to have global perfusion problems. In fact, it's hard to see global decrease uptake of tracer, you rarely see that. You would likely see whatever the region is that would be most devoid of uptake. So that might have been the inferior wall. You may not have had transient ischemic dilatation, you may not have had hypotension or anything else. So no other high risk features. You would've just looked at this as like, "Oh, this could be just single-vessel disease." Everybody's seen that. So, the angiogram really does, I think, remain a mainstay for this left main cohort.
Morton Kern, MD:
Let me just be provocative. We do catheter work. Sometimes people who have left main get their angiogram done and sometimes they crash, either because of us or in spite of us, it happens. Should we not replace angiography with CT angiography and not do invasive work first? Shouldn't this be a better test?
Michael J. Lim, MD:
Let's be forward-thinking rather than comment on what was done in your patient. What would be best? You said this guy was 72. In 19 years, if this is me, what should be done? If I have this type of angina and my risk factors, I think that a CT angiogram probably exceeds the benefit of our current stress testing capabilities. It gives you the ability to diagnose left main disease, the ability of understanding the other high risk features that we believe from a coronary distribution standpoint of stenosis, as well as give us appropriate functional information which is proven to correlate with invasive functional capabilities. So I think that's a great test. Economics are actually the thing that's going to drive the uptake of that test, versus the high degree of uptake in 2022 of nuclear perfusion stress testing. But from a test standpoint, if money is no object, the CT angiogram is preferred in my book.
Morton Kern, MD:
Well, Mike, we've been talking for 40 minutes, covered a lot of ground. I think that the issue of this last case is really on point for thinking ahead, because in my own approach to patients with coronary disease, I really like the CTA with the FFR attached to it. CTA-FFR is better than nuclear in my book. But that's worth an hour's discussion with detail and letting everybody flesh it out.
So I think this is a great point to stop our Cath Lab Digest Live today, at least we can call it cath lab and not CT lab. I'm going to say thank you to HMP Global. And thank you, Mike, for joining me. I hope to do a few more of these and it'll be interesting to have readers and listeners feedback. We'd love to have your input and address questions and issues that are pertinent to your life in the cath lab. Thanks very much.
Michael J. Lim, MD:
Thanks Mort, and thanks to HMP. Have a great day.
