Selected Podcast
Northwestern Medicine's Pulmonary Embolism Response Team
In this episode of the Better Edge podcast, Daniel R. Schimmel, MD, MS, associate professor of Medicine (Cardiology) and director of the cath lab at the Northwestern Medicine Bluhm Cardiovascular Institute, discusses Northwestern Medicine’s Pulmonary Embolism Response Team and how they take swift, coordinated action to save the lives of patients with pulmonary embolisms. Their multidisciplinary approach, along with new advanced technology, allowed them to become experts in the care of this disease.
Featured Speaker:
Daniel Schimmel, MD, MS
Dr. Daniel Schimmel is an Associate Professor of Medicine at Northwestern University and Hospital practicing interventional cardiology in the Bluhm Cardiovascular Institute. Dr. Schimmel attended medical school at Rush University and completed residency and fellowship training at Northwestern Memorial Hospital. Transcription:
Northwestern Medicine's Pulmonary Embolism Response Team
Melanie Cole (Host): At Northwestern Medicine, a new multidisciplinary team takes coordinated action to save the lives of patients with acute pulmonary embolism. Welcome to Better Edge, a Northwestern Medicine Podcast for physicians. I'm Melanie Cole. And joining me today is Dr. Daniel Schimmel. He's an interventional cardiologist, Associate Professor of Medicine in Cardiology, and he's the Director of the Cath Lab at the Bloom Cardiovascular Institute at Northwestern Medicine. He's here to discuss Northwestern Medicine's Pulmonary Embolism Response Team.
Dr. Shimmel, it's a pleasure to have you with us today. Thank you so much for joining us. Can you tell us a little bit about how Northwestern Medicine created this PERT team to provide the best possible care for patients with pulmonary embolism? How did this come about?
Dr Daniel Schimmel: Well, thank you for having me. This got started in conversation about eight years ago and it's continued to evolve over that time. But what we've found is that when patients present and are unstable or in shock with a pulmonary embolism and we classify as massive pulmonary embolism, we found that there was varied care depending on the groups that were called to the bedside, and we needed an interdisciplinary team that could provide a very fast consultation and then enact some tools that were infrequently used. And so, there's a team of providers who kind of championed it to become experts in the care of this disease process.
Melanie Cole (Host): Well then, tell us about your role on the Northwestern Medicine Pulmonary Embolism Response Team.
Dr Daniel Schimmel: So as an interventional cardiologist, I provide two roles. One of them is as an intensivist, coming to the bedside when the initial patient has the diagnosis and becomes unstable and then caring for them in our cardiac critical care unit. But also, I provide the procedures that can be used to remove clot, aspirate clot, or provide thrombolytics to the clot. And sometimes that's done at the bedside with IV pushes and infusions. Sometimes it's done as a complicated procedure and there are varied devices out now for pulmonary embolism and some of them have benefits in certain situations, while others might be better with other comorbidities. And so, it requires a knowledge of what devices are available.
And then, there's one other aspect that Northwestern has, which might not be available everywhere, but we're very lucky to be able to provide it, which is ECMO, which is putting someone on a heart lung bypass circuit emergently, sometimes at the bedside or in the cath lab to provide support for someone who might be in cardiac arrest or about to arrest from the pulmonary embolism.
Melanie Cole (Host): Wow, that's quite an advancement and very exciting. So, Dr. Shimmel, give us a little overview of how PERT is set up at Northwestern Medicine, the sequence of steps that take place once it's activated. What's involved in evaluating the patients with suspected pulmonary embolism? And how is the PERT team experienced at evaluating these patients quickly and making those care decisions?
Dr Daniel Schimmel: So for emergency response teams of this sort, there are two major types. One of them is a front-loaded response team where multiple disciplines are called to the bedside at once. And that was a style that we had very early on in the process. And that included hematologists, interventional radiologists, cardiac surgeons, interventional cardiologists, and ER physicians and pulmonologists. But over time, we realized that each of us had a different strength along the care pathway. And so now, we've moved more towards a tiered approach where an intensivist comes to the bedside and then can reach out to those disciplines as needed. So, that intensivist is either a critical care physician as myself. Sometimes our pulmonary critical care, rather than the cardiology critical care is the first call, but that person assesses the patient and decides what level of instability they're at.
And SCAI recently had some nice consensus guidelines on shock that were meant for the left side of the heart, but we've applied them here to the right side as well, and that helps us risk stratify patients a little bit more clearly so that we can decide if we're going to do something as extreme as putting them on the cardiac lung bypass circuit, or if we're going to take them to the cath lab and revascularize their lung circulation, or if we're going to provide anticoagulation and monitor in our critical care unit.
Melanie Cole (Host): Well then, speak about the data that shows outcomes. Are they effective in improving patient outcomes? Tell us a little bit about that.
Dr Daniel Schimmel: The data has been very difficult to show a mortality benefit with these tools. Both the tools that I've discussed, meaning the heart-lung bypass machine or any of the interventional therapies that are available. And a lot of that has to do with the heterogeneity of the disease process. We have risk scores that have been developed over many years. Many of them done in isolation, meaning that therapies were not associated with those risk scores. So, we know who's at risk, but studies haven't been done at the level that they need to to define a mortality benefit for those patients who have immediately a life-threatening pulmonary embolism other than systemic lytics, which was done a long time ago and, honestly, in a fashion that is not quite as robust as our current level of evidence with clinical trials. But systemic lytics do hold a place in the treatment therapy for acute PE for someone who's in shock or in cardiac arrest, but it hasn't been compared head to head with the heart-lung bypass machine, or these interventional strategies.
The biggest difficulty is that the systemic lytics is contraindicated in a great number of patients and, two-thirds of the time when it is indicated, physicians still are hesitant to give it because of the bleeding risks that are associated with systemic lytics. And when the adverse event profile is so high and it makes us hesitate to give a lifesaving therapy, well then we have to look at other strategies to support the patient. And that's where these other tools have come out.
Now as far as the team is concerned and what its effect has been, that has had a number of studies done on it as well, and there's been some varied results. But for the most part, it shows a decreased length of stay. There isn't necessarily an increase in interventional therapies. But there's definitely an improvement in the physicians and patients being comfortable with the therapies that are being recommended and given.
Melanie Cole (Host): Well, let's talk about some of those. And then, you've spoken about the multidisciplinary approach of the PERT team. So now, speak about the treatments that are available and how has technology for treating PE advanced greatly in recent years.
Dr Daniel Schimmel: Well, there's been a race to find an interventional strategy that decreases the risk of bleeding, but still improves blood flow to the lung circulation in order to both improve somebody's respiratory status. If they have increased work of breathing or hypoxia, that kind of falls outside the guidelines, but it's certainly an indication to provide advanced care.
And then when someone's in shock, there are therapies that are being used. So, the large categories that are available from the interventional lab include catheter-directed thrombolytics. And before 2014, there wasn't a whole lot of guidance on how to provide that therapy. Starting in 2014 though, there have been a number of studies looking to find the right dose and the right duration of infusion time for catheter-directed lytics to provide some guidance in order to get the best benefit with the lowest risk of bleeding. And then since then, a whole new category of catheter-directed devices that are not based on thrombolytics, but use suction embolectomy to remove clots have been developed. A number of manufacturers have devices that differ in some ways from each other, some with a quick aspiration, some with a continuous aspiration and a pump. There are new technologies meant to deliver blood back to the patient after aspirations, so we don't have large drops of hemoglobin with therapy. And there's even more devices that are currently undergoing development that try and capture it almost like in a basket. There are many more devices for deep vein thrombosis. But there are in the lung circulation some hurdles that have to be overcome for those catheter therapies to be developed to be effective and not be high risk.
I think the biggest thing for a cardiologist is that we've gotten very comfortable with large-bore access devices and moving them through the cardiovascular space, mostly because of the advancements in structural heart disease. So, a lot of that comfort level has now moved over into the pulmonary vascular space as well.
Melanie Cole (Host): Such an exciting time in your field, Dr. Shimmel. As we get ready to wrap up, I'd like you to give some bullet points, the key takeaway aways from this podcast for providers who are listening regarding the importance of this rapid response for pulmonary embolism, and what you would like to tell them about creating this type of program, if they would like to do that at their system. What's involved? Really, just give us your best advice.
Dr Daniel Schimmel: So, two questions there. The top three bullet points for treating acute pulmonary embolism, I'd say the first one is, if there are no contraindications, anticoagulate immediately. Low-molecular-weight heparin has been shown to get patients to a therapeutic anticoagulation goal faster than unfractionated heparin. And for most patients, most patients do not have that massive pulmonary embolism or the highest risk pulmonary embolism, anticoagulation alone is that strategy. And it should be provided quickly, and that saves lives.
The second thing is a lot of times as providers, we think to ourselves, "Well, this patient's systolic blood pressure is over 90, so they're not in shock. They're stable." But there are many signs that show instability besides a systolic blood pressure, whether it be an elevated lactate or rise in the creatinine. I rely a lot on heart rate to help me determine if someone is sick and unstable. If your heart rate's greater than your systolic blood pressure, that's an unstable patient, even if they don't meet the classic criteria for cardiogenic shock.
And the third thing that I think is really important, and this is a system intervention that needs to be had is that patients need to have a formatted, structured followup after they're discharged from the hospital with pulmonary embolism. Fifty percent of patients by six months have persistent symptoms and a decrease in quality of life. And there's education issues. When patients have higher risk PE, they're more at risk for this concept called chronic thromboembolic pulmonary hypertension, which is the thrombus or clot that doesn't resolve over time. Some studies suggest that when you come in with sub-massive, that your risk for elevated pulmonary pressures at six months might be as high as 16% or higher. And so, followup with a pulmonologist or cardiologist I think is very helpful for someone particularly who has RV, right ventricular dysfunction, when they show up with pulmonary embolism. So, those are my three bullet points for treating PE.
As far as the team's concerned, it's really important to have a group of people who are committed to learning about the devices, trying to parse through the data. When there is a lot of data to guide physicians, the team concept really isn't necessary because we have a defined pathway that no one really disagrees on. There are not as many nuances. When you have a disease that doesn't have as much data, but lots of tools and lots of options, some people who really understand those tools and can have a conversation about them and understand there are different ways to treat different patients is really useful. So, find some like-minded people who really are passionate about treating pulmonary embolism and create a team. And if nothing else, it's a way to look back at the data and make sure that you're providing quality care to the patients.
Melanie Cole (Host): Great advice. Such an educational podcast. Thank you so much, Dr. Shimmel, for joining us today. To refer your patient or for more information, please visit our website at breakthroughsforphysicians.nm.org/cardiovascular to get connected with one of our providers. And that concludes this episode of Better Edge, a Northwestern Medicine Podcast for physicians. Please always remember to subscribe, rate, and review this podcast and all the other Northwestern Medicine podcasts. I'm Melanie Cole.
Northwestern Medicine's Pulmonary Embolism Response Team
Melanie Cole (Host): At Northwestern Medicine, a new multidisciplinary team takes coordinated action to save the lives of patients with acute pulmonary embolism. Welcome to Better Edge, a Northwestern Medicine Podcast for physicians. I'm Melanie Cole. And joining me today is Dr. Daniel Schimmel. He's an interventional cardiologist, Associate Professor of Medicine in Cardiology, and he's the Director of the Cath Lab at the Bloom Cardiovascular Institute at Northwestern Medicine. He's here to discuss Northwestern Medicine's Pulmonary Embolism Response Team.
Dr. Shimmel, it's a pleasure to have you with us today. Thank you so much for joining us. Can you tell us a little bit about how Northwestern Medicine created this PERT team to provide the best possible care for patients with pulmonary embolism? How did this come about?
Dr Daniel Schimmel: Well, thank you for having me. This got started in conversation about eight years ago and it's continued to evolve over that time. But what we've found is that when patients present and are unstable or in shock with a pulmonary embolism and we classify as massive pulmonary embolism, we found that there was varied care depending on the groups that were called to the bedside, and we needed an interdisciplinary team that could provide a very fast consultation and then enact some tools that were infrequently used. And so, there's a team of providers who kind of championed it to become experts in the care of this disease process.
Melanie Cole (Host): Well then, tell us about your role on the Northwestern Medicine Pulmonary Embolism Response Team.
Dr Daniel Schimmel: So as an interventional cardiologist, I provide two roles. One of them is as an intensivist, coming to the bedside when the initial patient has the diagnosis and becomes unstable and then caring for them in our cardiac critical care unit. But also, I provide the procedures that can be used to remove clot, aspirate clot, or provide thrombolytics to the clot. And sometimes that's done at the bedside with IV pushes and infusions. Sometimes it's done as a complicated procedure and there are varied devices out now for pulmonary embolism and some of them have benefits in certain situations, while others might be better with other comorbidities. And so, it requires a knowledge of what devices are available.
And then, there's one other aspect that Northwestern has, which might not be available everywhere, but we're very lucky to be able to provide it, which is ECMO, which is putting someone on a heart lung bypass circuit emergently, sometimes at the bedside or in the cath lab to provide support for someone who might be in cardiac arrest or about to arrest from the pulmonary embolism.
Melanie Cole (Host): Wow, that's quite an advancement and very exciting. So, Dr. Shimmel, give us a little overview of how PERT is set up at Northwestern Medicine, the sequence of steps that take place once it's activated. What's involved in evaluating the patients with suspected pulmonary embolism? And how is the PERT team experienced at evaluating these patients quickly and making those care decisions?
Dr Daniel Schimmel: So for emergency response teams of this sort, there are two major types. One of them is a front-loaded response team where multiple disciplines are called to the bedside at once. And that was a style that we had very early on in the process. And that included hematologists, interventional radiologists, cardiac surgeons, interventional cardiologists, and ER physicians and pulmonologists. But over time, we realized that each of us had a different strength along the care pathway. And so now, we've moved more towards a tiered approach where an intensivist comes to the bedside and then can reach out to those disciplines as needed. So, that intensivist is either a critical care physician as myself. Sometimes our pulmonary critical care, rather than the cardiology critical care is the first call, but that person assesses the patient and decides what level of instability they're at.
And SCAI recently had some nice consensus guidelines on shock that were meant for the left side of the heart, but we've applied them here to the right side as well, and that helps us risk stratify patients a little bit more clearly so that we can decide if we're going to do something as extreme as putting them on the cardiac lung bypass circuit, or if we're going to take them to the cath lab and revascularize their lung circulation, or if we're going to provide anticoagulation and monitor in our critical care unit.
Melanie Cole (Host): Well then, speak about the data that shows outcomes. Are they effective in improving patient outcomes? Tell us a little bit about that.
Dr Daniel Schimmel: The data has been very difficult to show a mortality benefit with these tools. Both the tools that I've discussed, meaning the heart-lung bypass machine or any of the interventional therapies that are available. And a lot of that has to do with the heterogeneity of the disease process. We have risk scores that have been developed over many years. Many of them done in isolation, meaning that therapies were not associated with those risk scores. So, we know who's at risk, but studies haven't been done at the level that they need to to define a mortality benefit for those patients who have immediately a life-threatening pulmonary embolism other than systemic lytics, which was done a long time ago and, honestly, in a fashion that is not quite as robust as our current level of evidence with clinical trials. But systemic lytics do hold a place in the treatment therapy for acute PE for someone who's in shock or in cardiac arrest, but it hasn't been compared head to head with the heart-lung bypass machine, or these interventional strategies.
The biggest difficulty is that the systemic lytics is contraindicated in a great number of patients and, two-thirds of the time when it is indicated, physicians still are hesitant to give it because of the bleeding risks that are associated with systemic lytics. And when the adverse event profile is so high and it makes us hesitate to give a lifesaving therapy, well then we have to look at other strategies to support the patient. And that's where these other tools have come out.
Now as far as the team is concerned and what its effect has been, that has had a number of studies done on it as well, and there's been some varied results. But for the most part, it shows a decreased length of stay. There isn't necessarily an increase in interventional therapies. But there's definitely an improvement in the physicians and patients being comfortable with the therapies that are being recommended and given.
Melanie Cole (Host): Well, let's talk about some of those. And then, you've spoken about the multidisciplinary approach of the PERT team. So now, speak about the treatments that are available and how has technology for treating PE advanced greatly in recent years.
Dr Daniel Schimmel: Well, there's been a race to find an interventional strategy that decreases the risk of bleeding, but still improves blood flow to the lung circulation in order to both improve somebody's respiratory status. If they have increased work of breathing or hypoxia, that kind of falls outside the guidelines, but it's certainly an indication to provide advanced care.
And then when someone's in shock, there are therapies that are being used. So, the large categories that are available from the interventional lab include catheter-directed thrombolytics. And before 2014, there wasn't a whole lot of guidance on how to provide that therapy. Starting in 2014 though, there have been a number of studies looking to find the right dose and the right duration of infusion time for catheter-directed lytics to provide some guidance in order to get the best benefit with the lowest risk of bleeding. And then since then, a whole new category of catheter-directed devices that are not based on thrombolytics, but use suction embolectomy to remove clots have been developed. A number of manufacturers have devices that differ in some ways from each other, some with a quick aspiration, some with a continuous aspiration and a pump. There are new technologies meant to deliver blood back to the patient after aspirations, so we don't have large drops of hemoglobin with therapy. And there's even more devices that are currently undergoing development that try and capture it almost like in a basket. There are many more devices for deep vein thrombosis. But there are in the lung circulation some hurdles that have to be overcome for those catheter therapies to be developed to be effective and not be high risk.
I think the biggest thing for a cardiologist is that we've gotten very comfortable with large-bore access devices and moving them through the cardiovascular space, mostly because of the advancements in structural heart disease. So, a lot of that comfort level has now moved over into the pulmonary vascular space as well.
Melanie Cole (Host): Such an exciting time in your field, Dr. Shimmel. As we get ready to wrap up, I'd like you to give some bullet points, the key takeaway aways from this podcast for providers who are listening regarding the importance of this rapid response for pulmonary embolism, and what you would like to tell them about creating this type of program, if they would like to do that at their system. What's involved? Really, just give us your best advice.
Dr Daniel Schimmel: So, two questions there. The top three bullet points for treating acute pulmonary embolism, I'd say the first one is, if there are no contraindications, anticoagulate immediately. Low-molecular-weight heparin has been shown to get patients to a therapeutic anticoagulation goal faster than unfractionated heparin. And for most patients, most patients do not have that massive pulmonary embolism or the highest risk pulmonary embolism, anticoagulation alone is that strategy. And it should be provided quickly, and that saves lives.
The second thing is a lot of times as providers, we think to ourselves, "Well, this patient's systolic blood pressure is over 90, so they're not in shock. They're stable." But there are many signs that show instability besides a systolic blood pressure, whether it be an elevated lactate or rise in the creatinine. I rely a lot on heart rate to help me determine if someone is sick and unstable. If your heart rate's greater than your systolic blood pressure, that's an unstable patient, even if they don't meet the classic criteria for cardiogenic shock.
And the third thing that I think is really important, and this is a system intervention that needs to be had is that patients need to have a formatted, structured followup after they're discharged from the hospital with pulmonary embolism. Fifty percent of patients by six months have persistent symptoms and a decrease in quality of life. And there's education issues. When patients have higher risk PE, they're more at risk for this concept called chronic thromboembolic pulmonary hypertension, which is the thrombus or clot that doesn't resolve over time. Some studies suggest that when you come in with sub-massive, that your risk for elevated pulmonary pressures at six months might be as high as 16% or higher. And so, followup with a pulmonologist or cardiologist I think is very helpful for someone particularly who has RV, right ventricular dysfunction, when they show up with pulmonary embolism. So, those are my three bullet points for treating PE.
As far as the team's concerned, it's really important to have a group of people who are committed to learning about the devices, trying to parse through the data. When there is a lot of data to guide physicians, the team concept really isn't necessary because we have a defined pathway that no one really disagrees on. There are not as many nuances. When you have a disease that doesn't have as much data, but lots of tools and lots of options, some people who really understand those tools and can have a conversation about them and understand there are different ways to treat different patients is really useful. So, find some like-minded people who really are passionate about treating pulmonary embolism and create a team. And if nothing else, it's a way to look back at the data and make sure that you're providing quality care to the patients.
Melanie Cole (Host): Great advice. Such an educational podcast. Thank you so much, Dr. Shimmel, for joining us today. To refer your patient or for more information, please visit our website at breakthroughsforphysicians.nm.org/cardiovascular to get connected with one of our providers. And that concludes this episode of Better Edge, a Northwestern Medicine Podcast for physicians. Please always remember to subscribe, rate, and review this podcast and all the other Northwestern Medicine podcasts. I'm Melanie Cole.