P. Matthew Belford, MD, assistant professor of Cardiovascular Medicine at Wake Forest School of Medicine, presents a case study and an overview of hemodynamic (HD) support for patients with acute coronary systems. He also provides specifics on four modes of HD support: IABP (intra-aortic balloon pump), ECMO (extracorporeal membrane oxygenation), Impella and TandemHeart™.
MATTHEW BELFORD: So the requisite No Disclosure slide, I don't have anything to disclose. This is really the first of two talks and TJ O'Neill's is going to take the second part of this. I'm going to talk about the acute phase, and the immediate things we can do for patients. And he's going to really bring home the second half of what we do for these very, very complex patients. I'm going to talk about a case, obviously just a quick overview of four modes of hemodynamic support, and then a case wrap up and discussion. And then hand off to TJ to talk about what do we do with those patients after we deal with the acute issue. So like all good clinical talks, we're going to start with a case. 51 year old mail with known coronary disease. Had a history of a PCI, stint-- some point back in time, we don't know when-- to his LAD. Stint back to the right coronary as well. Presents emergency department at Baptist with about an hour of crushing chest pain. Pretty classic story. He didn't take his Plavix the morning of presentation. Presented with 1-2 millimeters ST elevation and leads 1, AVL an inferior ST depression. He's hypoxic, looks like he had some pulmonary edema in the emergency department. Ultimately gets intubated in the emergency department before coming up to us in the cath lab. Upon arrival, profoundly hypotensive. So the first thing we did was go ahead and put in a balloon pump for cardiogenic shock. And I keep hitting the wrong button. And so these are some pictures. So this is a bad day. This is a bad day if you're the patient. It's a bad day if you're an interventional cardiologist. This patient's got-- you can see that stint in the upper left hand corner-- that's his left anterior descending, that's not got any blood going to it. And then you can see the thing that dead ends to the bottom left-- bottom right, there is actually his circumflex artery. And that's also 100% accluded. This is another shot. Basically the same thing. You can see that LAD going away from you there, and the circumflex is coming down towards you. You can see that he's clearly had some stuff done in the past. That snake-like looking thing off to the left side of the screen's a defibrillator lead. And then the tip bouncing in the breeze there is our balloon pump. So now, we're going to have to start working on him. Well, his EKG indicates he's having a lateral ST elevation. So clearly, that's probably the acute process, so we're sort of trying to step through what we're doing here. So we'd now snuck a wire. a coronary wire, down the circumflex artery there. And sure enough there's a blood vessel. So now we've got something to work with. So we at least open that up. Actually in this picture, it's in the top of the guide in the upper left corner there, you can actually see the tip of our balloon. We've at least got some artery there. All right. Now we've got this thing open. Now we put a stint there in the proximal circumflex, and all of a sudden, you've got blood flow. All right. We're done, right? Every body's going home? We're good? Not so much. So now you take a breather, and we step back and say, what are we going to do with this guy? Now you've got a moment to dig through the medical record and say, huh, well he was previously evaluated by heart failure. He pretty much said, no thank you, not interested. Don't want to do any of that stuff. He continued to smoke. Obviously wasn't so great about taking his Plavix. And so now you've got this decision tree of options. And like I said, we've got those four immediate things that you can do in the cath lab, balloon pump-- which we already did-- ECMO, Impella, tandem heart. So why do we pick these things? What are they? What do we do with them? And what good are they? And those are important questions. So just generally, broad speaking, I'm not going to bore you guys with lots of guidelines. I like to think in big picture level things. What do we do for patients who dying? What do we do for people who need something other than just a little bit of pressor support. Broadly speaking, mechanical support devices it's gotta have some place to go with it. It's either a bridge to recovery, or definitive treatment. You've got to know what you're doing it for. It is acute MI? It this myocarditis? Is this a person with cardiomyopathy of some other etiology? Or is this in perioperative-- I have on there post open heart surgery, but is this in the perioperative setting? Is this someone we're about to fix their heart surgically? Chronic LV dysfunction, TJ's going to talk a little bit more about that in terms of is this a bridge to some option, either heart transplant, or bridge to LVAD. Certainly for high-risk surgery, high-risk PCI, all these devices are indicated for that. And then, actually, we're really growing the population. And you guys heard from Doctor Whalen earlier. But of high-risk VT ablation. So these are patients who are going to have something very complicated done in the electrophysiology lab. They're going to be in a lethal rhythm for a period of time. And they need some sort of support for that procedure. Generally speaking-- if you're just thinking about some numbers-- off to the right there. Systolic blood pressure of less than 90 for 30 minutes. Cardiac index less than 2.2. Pulmonary capillary wedge pressure greater than 50. Those are number in the back of my mind when we're talking about these things. I do this talk a lot for EMS agencies. And this is what I describe to paramedics and say, look this is what you see when someone is dying. This is the physiology, as written out, for someone who is acutely decompensating on you. It's this combination of both systolic and diastolic dysfunction that are happening acutely. Their cardiac output drops, their stroke volume drops, systemic profusion drops they, suddenly become hypotensive, what does the body do to that? Well now your coronary profusion pressure goes down. And again, the heart, the ventricle, the pump that needs all that blood is now having more trouble doing what it needs to do. So it just becomes this death spiral. They become more ischemic. They progressively have a decline in LV function, and they get sicker and sicker, ultimately leading to death. So what do we do? As interventional cardiologists, as people who work with patients, we've got to stop this somehow. What are we going to do to fix this? How are we going to interrupt that cascade? We have this whole spectrum of things. And this goes from the simplest thing, a balloon pump-- been around forever and ever and ever, we use it like crazy-- all the way up to the true mythical unicorn device, the true total artificial heart. I can tell you there's a couple iterations of this, and that's certainly one of those things that we really would love to have a perfect device. There's just not one, unfortunately. And then somewhere on that spectrum's Impella, I'm going to talk about that. Obviously, Tandem, ECMO-- I'm going to briefly talk about that. And then TJ's going to take the second part of that, the more complex devices, particularly focused around vPADs. There's a lot of guidelines on this, there's a lot of data. I can brag on Doctor Zhao, why? Because he's not here. Point two, because he's my boss. But he probably didn't mention earlier, but he's actually the lead author, was the senior author in the 2013 Standing Guidelines. So you've got a topical expert talking to you about that. But there's pieces in there about mechanical support, and what do we do for these patients when they're doing it. And then there was actually a slight update in 2015. And I will boil all that down into three brief words. So highlights. So basically, provide superior hemodynamic support compared pharmacological therapy. What does that mean? That means pressors, OK? These things do better than pressors. That's fair. Particularly true for Impella and TandemHeart. And we'll talk about some of the data around balloon pumps in a bit. Cardiogenic patients are high risk. This is not surprise. I'm talking about somebody who's acutely dying and we're going to do something for them. Well yeah, they're sick. So we know the outcomes across the board are bad. So what do we have? That means we have a lot of margin for improvement on these patients. So mortality is high despite pressors, despite other things we're doing in terms of pharmacotherapy. And mechanical support may be considered in those who fail to stabilize. So do the obvious things. Do the things that we know rescue patients and make people better. And when that doesn't work, now we've got these options that we can pull out. And then, here's the kicker. In cardiogenic shock, a balloon pump is less likely to provide benefit. This is the dilemma for an interventional cardiologist. This device is ubiquitous. Every cath lab has one. We're usually more comfortable with them. We know how to use it. It's quick. It's very easy, generally speaking. It also doesn't work. So the other devices and that are probably better in the sense that continuous flow from either Impella or TandemHeart or ECMO for patients that also have concomitant respiratory dysfunction. What percentage of these patients have concomitant respiratory dysfunction? A lot. That's extremely high. So just kind of just touching on the overview of all these things. All right. balloon pump. So what does a balloon pump do? It's a big balloon that sits in your aorta. It blows up in diastole and it goes down in systole. Seems reasonably straightforward. Reasonably easy to put in. Is unfortunately dependent on intrinsic LV function and requires a stable rhythm. Well we already talked about what are these patients? These are patients, inherently, that probably don't have normal intrinsic LV function. And by definition, they're extremely high risk for underlying arrhythmias. So the implicit things that make a balloon pump work aren't always true for these patients. Clearly, it is the most widely used form of mechanical support. Every cath lab has one. A lot of places, unfortunately, it's the only thing they have. Yet, it is the only of our devices that actually have a Class One recommendation-- again, the guideline is outdated-- from ACCHA and the original STEMI guidelines. Why? Because we all know it. We all use it. We're all comfortable with it. So what are the reasons you wouldn't want to use one of these? Well, if the patient's got a wide open aortic valve, right? I already you that the thing inflates in systole and goes down in diastole. So if their aortic valve is leaking, then you don't want to do anything that's going to add a whole lot of back pressure, acutely. Certainly if they've got vascular disease-- now this is obviously something we run into a lot and you don't necessarily always have time to know that-- but certainly, if they have an underlying AAA or an underlying aortic disease, that's obviously relative contraindication. And then significant PAD. Again, it's reasonably quick for us to make just a quick ballpark assessment. They are a reasonably low profile device in that sense, in terms of getting in. Well, we're a bunch of scientists. We're a bunch of doctors. Let's do a trial. Right? It seems easy. It seems obvious. So let's take a bunch of people, and a bunch of patients that come in in cardiogenic shock. And what we're going to do is we're going to give some of them a balloon pump. And we're going to give some of them no balloon pump, right? Standard of care. Seems easy. Seems obvious. So we did this. Its' called the Shock II Trial. 600 patients, randomized. Initially, obviously, it's kind of hard to blind a balloon pump. Primary endpoint with 30 day, all cause mortality. And so here's your research slide for my talk. And you can just kind of quickly scan down the P Value chart there. And you see 0.69, 0.16, 0.71, 0.28, et cetera. What it does mean for non-research folks? That means there was no statistical difference between the two groups. Hm-mm. Well, that's concerning. If you take a graph and do what's called a Kaplan-Meier curve, and you basically take the red line is people that get a balloon pump and the blue line is people who get no balloon pump. And you graph it out for days after randomization. There's a dotted line up there at a year. And what's the 12 month mortality between the people that got the lifesaving balloon pump and the people that got the standard of care? No difference. So at 12 months, there was no difference, and all cause mortality reinfarction, recurrent revascularization, stroke, or any quality of life measures. Why do we continue to use these devices? We're comfortable with them. We know that they "work," right? And so we do it. And so it's really time for us to move on past the balloon pump. It's time for us to do something different. And I say that and I put one in yesterday. So, I'm cognizant of this. So ECMO. So ECMO, for many years in my mind, had a bad thing attached to it. That's because of the primary use for ECMO. So what is it? Extracorporeal Membrane Oxygenation. It's a method of gas exchange, allows the lungs to rest. And you can continue basically ventilating the patient outside the body without their lungs in place. This is actually really is an evolution in bypass. All this stuff-- I had this great slide in there and I said I've got to get this down to 30 minutes-- sort of the evolution of this. And it's actually all stuff that was developed in the 1970s when we were really developing bypass. We figured out how we could oxygenated blood, how we could pump it back in safely, back into patients, and that was the evolution of it ECMO. This thing is great. This thing's wet prep, ready to go in the cath lab. We've got a big bag, we drag out our big bag, we drag the machine around the corner, and we can get this thing in quick, 10 minutes even with CPR ongoing. And it's an easy option, in terms of transition. At that point, you have complete control. Great hemodynamic control, great respiratory control. So all of a sudden, now you've got blood flow. And for an intervention cardiologist, if I've got blood flow, that gives me options. There's things we can do. This is it. These are some pictures, actually, in our old unit. Venous inflow, 21-25 French, we're talking big cannulas, big things, like bigger than my thumb. It goes through the circuit, oxygenates the blood, and then goes back into an artery. Where does it go? Back into a leg artery. OK. Now obviously, any time you're punching two big holes in somebody, there are potential complications associated with this. That's actually one of the roller pumps we use. Obviously, those are the cannulas, these are big bore things, there's obviously a lot of blood in the circuit. If you're a bit of a data nerd like me, it's actually fantastic, because look, you get all of those nice numbers right there, constantly looking at you in terms your patient pH, PCO2, et cetera. This is an old slide, but I think it's compelling and it's actually interesting when you start talking to the EMS agencies. Our rates of survival for CPR have gone up dramatically. OK? We've done this with active changes in how CPR gets done in the field, what we're doing, how we're rescuing patients. That being said, when you compare that to ECMO assisted CPR, obviously, it's dramatically different, right? If you're in an ECMO, you've got blood flow. So your CPR's going to be dramatically more successful. Look at that out at the end. Obviously, 60 minutes, at greater than 60 minutes, there's still a survival to discharge of over 20% for folks on ECMO. In the setting of they get CPR and get ECMO put in in the setting of it. There's probably some bias, in terms of what patients are included in that, but that's still pretty impressive. I can't tell you on one hand the number of codes I've been involved in that are more than 60 minutes where the patient has survived to discharge. So part of the challenge is us picking which patients will do well with this and which patients will do well with this versus some of the other devices we have. Unfortunately, a lot of the literature has been revolved around my prior negative associations with ECMO because we think of it for ARDS, right? And that's a disease that those people are incredibly sick, and probably will not get better immediately, soon, and have an incredibly high mortality to begin with. So unfortunately, they're kind of two different groups. And they're very different than the STEMI population. Certainly, those that have reversible conditions, is it a STEMI? Is it myocarditis? Is it some underlying cardiomyopathy? Those are patients that are going to do better on this device. It's a great bridge to something. It's a bridge to whatever that may be, a ventricular assist device which Doctor O'Neill is going to talk about in a moment. Contraindications. There's a lot of relative contraindication to these. Obviously, if you've been on a ventilator, you've been very sick for a prolonged period of time, I would consider that a relative contraindication. If you don't have the ability to anticoagulate these patients, that is an absolute contraindication. And again, I think the other piece on this is what is their overall prognosis? That's something we talk about at Baptist, is let's identify what's the chance that this person's going to get better and then have some viable outcome long-term? And that's something we try and talk about and think about before we start doing some of these advanced options. What are the complications? Well obviously, the case we're going to punch two big holes in somebody and we're going to put them on a pump for a long time. Well, you could punch holes in things you're not supposed to. You could block things you're not supposed to. We certainly worry about blood flow down the leg. Any time, obviously, you've got a large cannula in a very small vessel, we actually will often put another cannula down, another sheaf actually going forward. Since you've got a pump, we can actually loop some of that blood flow back around to go back down the leg and profuse the leg. Certainly they can have bleeding complications, infections, AV fistula, significant thrombocytopenia associated with the pump alone. All right, Doctor Belford, how does this apply to me? You've got me sitting in this conference and I got this stuff that I want to talk about, you've got the stuff that you want to talk about. This is something you're going to see. I love this slide from a few years back-- actually, not a few years back, all the way back in January-- I don't know if you guys read Wired, but it's a little bit of a tech nerd, computer site. And I was flipping through one day and I saw this. I thought, oh! "Flying Hospital Rushes Wounded Soldiers to Safety." Fair. That might be interesting. That might catch my attention. And it's actually talking about the C-17s that the Air Force has and they actually have four bays in here. It's basically like the world's largest ambulance, right? They've got four bays. They actually triage patients. They've got a small OR on there. They've got all of these sundry critical care things that you could think of. And it was just interesting reading about the processes, and what they do, how they pick the patients. So I go back in the back of the article, and they've got one of those little inserts off to the sides. It says "Critical care, the ICU is equipped with pacemakers, IV fluids, and drugs" Fair. All interesting. The planes can bounce around. That's exciting. And then on the side, it says "Medical oxygen." I think major trauma, right? And what's it say? It says "Soldiers whose lungs can't oxygenate their blood have a flight-optimized extracorporeal membrane oxygenation machine to do it for them. It pulls oxygen from tanks in the plane's nose and pumps it into the blood." What is this? This is ECMO, OK? This is where we're going. That's an ECMO unit that's actually a super small version of one of the ECMO units that we've actually looked at. And you see that's stuck on the back of a hospital gurney, so for critical care transport. This is the wave of the future. This is where these devices are going. These devices are going to get to the point where we can go in the field, put this in, and then get them somewhere. And certainly, if you're a critical care, EMS kind of person, this is revolutionary. This is game changing. That's just a quick diagram of the Cardiohelp made by Maquet. Cardiohelp in terms of the femoral arterial outflow there. And then obviously, we're pulling blood in from a large, or a venous, or cannula. Impella, second device. This is a device that has evolved over time and is actually very nice, very easy, very easy to put in quickly as well. The newest device, actually, is their CP device which you can put about 3.5 liters per minute out. Effectively, this is a-- I would describe as a jet ski with a snorkel. The thing sits down in the bottom of the left ventricle, sucks blood out of the heart itself, pumps it out into the aorta. Which is exactly what the heart should be doing. We have, actually, an older version of the device which is 2.5 liters a minute, the new version which is 3 and a 1/2 liters a minute. And a large device, which actually has to be surgically implanted that's actually 5 liters a minute in terms of support Again, great for high-risk PCI. So for these patients who I'm concerned that when I'm working on them, their blood pressure is going to go to zero, Impella's perfect for these patients. It does require some intrinsic cardiac output. It does have some issues in terms of hemolysis, in terms of device location. They are very easy to put in, almost as easy as a balloon pump, which is nice. And a lot of times, if you're not using the 5 liter a minute device, they're not really full support, like ECMO is, they're a little bit more partial support. That's basically the anatomic picture version of what I just described to you. Obviously, the device sits down in the left ventricle, pumps the blood out in the aorta. It's perfect. This was actually a picture of a patient we did. Obviously the pump inlet there sitting in the left ventricle, you can actually see there's a patient with a defibrillator. So they probably have existing heart failure before they did it, because you can actually see those are defibrillator leads. And then up there by the dark part in the upper left, you can see that's actually where the motor housing s and that's where the blood is pumped out into the aorta. So how do these devices get approved? Well, this is where it gets a little tricky, because from the FDA's point of view, they want to see with this is they want to see that the device is no worse than the standard of care. Well, what's the standard of care? Balloon pump. What did I tell you about balloon pump. Doesn't work. So we took 25 patients in cardiogenic shock, we gave half of them balloon pump. We gave half of them an Impella. And we found no difference between the two. Well that makes me as an interventional cardiologist a little bit, kind of raise your eye, because clearly in my mind and my clinical experience, this device does better than that. But hey, from the FDA's point of view, we're good, we're approved. Let's use them. So conclusion, it's easy. It's not cheap. It is certainly useful in some roles. It is very quick and easy for us to get in the cath lab. In terms of long term transition, the surgically implanted ones are probably easier to transition to some sort of a long-term device. TandemHeart. We'll try to pick up the pace here a little bit. Up to 4-5 liters a minute. This is very similar to ECMO, OK? We basically suck blood out of something and we pump it back into the leg. The difference is there's a unique element to this, and that is, we skip the lungs. So instead of just bypassing the lungs completely, what we actually do is take one of the catheter, take the inflow catheter that's sucking blood out of the heart, and actually punch it from the right atrium into the left atrium. So we're actually really just unloading the left ventricle. So we're pulling blood out of the left atrium, running it through the machine, adding pressure to it, and we're adding it back into the body. So you're really offloading a dying left ventricle. It is a nice device. It is a nice device that you can leave in for a long period of time. It is really truly a percutaneous pVAD in that sense. And TJ's going to talk to you a little bit more about pVADs. The actual FDA list is a few hours to 14 days. There are some limitations in terms of long term things. We've certainly had patients on these far longer than that. Part of the challenge is putting this thing in. It's not as easy to put in as the Impella. It's not as easy to put in as ECMO. You're obviously having to punch a hole through the heart. And so that adds an extra level of complexity. And again, when we're talking about one of those patients that's spiraling down and dying quickly, it's not the time for us to be playing around with a transseptal puncture. Continuous flow is nice. You do get up to 4 liters, in some cases 5 liters a minute of cardiac output. It very quickly unloads the left ventricle. The left ventricle is much happier with one of these devices in. And it definitely provides more support than a balloon pump. Part of the challenge of it is, like I said, is getting through the complications. Obviously, you're puncturing a hole in the heart with a catheter. So puncturing aortic root, the coronary sinus, or the posterior wall of the atrium in a person who is already dying is probably not good. And then all the other things you can imagine for having a cannula and a pump in. Just like the Impella, they basically did the same thing. Obviously to clear FDA guidelines, they did a European study, small number of patients, and what did they do? They compared TandemHeart to balloon pump. And there was, again, no statistical difference. I think part of that's just that it's a small study and it's not really powered for much difference. So conclusion, similar to ECMO does require transseptal puncture and offloads the left ventricle. So back to our case. Now we've talked about the things. So what d we do? We saw those pictures from earlier. We already opened up the circumflex. The guy continued to be a cardiogenic shock. So what do we do We talked to the heart failure team. We talk to the cardiothoracic surgery team. We say, what options do we have for this patient? At that point, we said, the quickest and easiest thing for us to do-- he's got impaired gas exchange-- would be, actually, to put him on ECMO. So actually, what do we do? We actually upsize the holes we've already made. We've already got a hole in an artery. We've already got a hole in a vein that we had made for a potential pacemaker. And we just make those real big holes. So we upsize both those cannulas, so he gets what's we call VA-ECMO-- so venoarterial ECMO-- So you're pulling blood from his left femoral vein, which is 26 French hole, and you're pumping the blood back into his right femoral artery-- which I think was a 17 French hole for him. And we left the balloon pump in. We already had it in. We left it in Why? It adds little bit a pulsatile flow in a continuous flow systems. So that's actually better physiologically for the body. Actually, two days later, due to concerns of what we were doing, we actually did a hybrid. And this is a nice thing that we can do with ECMO. And that is, now we take a transseptal cannula, and we basically punch a hole through the heart-- like we talked about earlier-- and we, basically, now start sucking blood from the left atrium. And basically, this becomes a combination device. So at this point, it's ECMO plus Tandem, all running through one machine. So we actually had total control, in terms of offloading both the right and the left heart. Was seen by heart failure team, ultimately planned an LVAD as destination therapy, which I'm going to hand off to TJ on that piece. We've really had some amazing successes with these devices. Just highlighting in the last 18 months. We had a 17-year-old brought to us from an outside hospital with a PEA arrest. She actually has done fantastic. And it's just really nice to see these patients that come in that are literally dying in front of you. You do some aggressive intervention, and all of a sudden, they're back to normal and healthy people. We had an inferior STEMI in the 70s. He did have a long hospital course, but basically, largely got back to normal. We had 34-year-old who came in and-- unfortunately, I guess now about two years ago-- severe diffuse, multivessel disease kind of stuff that gives even me chest pain, who arrest at home with a STEMI. Ultimately gets thrown on ECMO, gets multivessel PCI, ultimately, gets a heart transplant, and has done very well since. So again, just sort of broad and tie it all back together again. Indication. Obviously reduced LV function, complex PCI and some sort of high-risk condition. And again, these patients, they are sick, catastrophe is just one step away. We talked about some of the limitations with balloon pump, obviously, LV assist devices are growing role and then ECMO really has a lot of wins as well, because it is so easy to put in and nice for short term support. We clearly need more data on this. And I'm not going to bore you with, we've got lots and lots of small trials, but we really don't have a big, huge randomized control trial, which is really what we would like to have. That, actually on the right, you see is, actually, is a four chamber view of the heart. The big white thing is actually his left ventricle. And that's a ventricle that not moving and full of thrombus, full of clot. And you don't really see much moving on the left side, but sort of faintly in that bottom chamber down there, you see sort of something kind of squeaking through there. And if you pay attention to the little bit of the rhythm, you can see-- I can't point at my laser on it-- but down at the bottom side, there you can sort of see, say, you know, ask the EMS guys, what rhythm is this? Well, that's ventricular fibrillation. And how surprised would you be if I told you this guy was awake, alert, and talking to us? He actually came in as a STEMI, diffuse multivessel disease, and we actually put a TandemHeart in the cath lab. And he's awake, alert, and talking to you, in VFib with that ventricle. We actually got a call from the echo lab that said, why are we echoing dead people? Which is a gratifying phone call to be on the other end of. I said, let me let you talk to the patient. So this is the save. And this is the benefit for these devices. And so, I'm going to hand off at that point to TJ and let him take home where we go from there with these patients.
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