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The Search for the Holy Grail of New PE Devices

BY MAHIR ELDER, MD, FACC, FSCAI, AND TERRY BOWERS, MD, FACC, FSCAI

Pulmonary embolism (PE) is a growing field in endovascular intervention, with a robust ongoing search for the endovascular “holy grail” to treat this life-threatening disease. Patients presenting with PE are now routinely risk-stratified with PE response team (PERT) algorithms to identify those with hemodynamic instability and right ventricular (RV) dysfunction. For patients with intermediate-high and high-risk features characterized by European Society of Cardiology criteria, care is escalated with systemic thrombolysis or endovascular approaches. The endovascular holy grail is a device that can be used by one operator in a stand-alone procedure, with minimal bleeding and periprocedural risk, effective clot resolution, and minimal blood loss. Numerous devices have emerged throughout the past 10 years, but they have failed to meet all of these criteria. Many of the existing thrombectomy devices commonly used to treat venous thromboembolism have been repurposed from other medical devices and have undergone new iterations.

There is no guideline-directed endovascular approach at this point, but the field is quickly moving forward with innovative devices and clinical trials to establish benefit. To date, no device has been shown in randomized trials to improve survival. This article outlines the currently available devices and discusses their supporting data.

Endovascular initiatives have progressed in two directions to allow for expeditious therapy and significant eduction of bleeding risk: (1) by reducing the dose of thrombolytic therapy required to achieve therapeutic benefit (EkoSonic endovascular system [EKOS; Boston Scientific Corporation], Bashir endovascular catheter [Thrombolex, Inc.]), or (2) with thrombectomy approaches (FlowTriever [Inari Medical], Indigo aspiration system [Penumbra, Inc.]).

Our current strategy at Beaumont Health is to discuss each escalation patient on a multidisciplinary PERT call and tease out clinical and CTA criteria to guide escalation. Recent device trials have focused on rapid improvements in RV/left ventricular (LV) ratios as assessed by CTA as proof of benefit (Table 1).1-4 Clinical improvement as determined by improvements in heart rate and oxygen requirements, and subjective improvements in dyspnea serve as our point-of-care endpoints. Length of stay has been shortened with the PERT risk stratification algorithm and the current escalation strategies.

REDUCED-DOSE THROMBOLYTIC THERAPY
The tissue plasminogen activator (tPA)–based approaches that have gained momentum are EKOS ultrasound-assisted thrombolysis (USAT) infusion and the Bashir endovascular catheter. Both have demonstrated effective clot lysis, achieving clinical endpoints with doses of tPA reduced to < 24 mg. Ongoing research is being pursued to understand the microvascular benefits of thrombolytic infusion that may occur beyond simple extraction of large visible clots via thrombectomy. Three-dimensional CTA is being used to characterize the blush score and evaluate microvascular perfusion before and after USAT.5 These devices have been compared with anticoagulation-alone strategies in patients with submassive PE. As we move forward, identifying specific patient types for different strategies will help optimize outcomes. At Beaumont, we have evolved into a thrombectomy-first approach for proximal clot and a catheter-directed tPA approach for more diffuse and distal clot. Since January 2019, we have escalated therapy in 125 intermediate-high–risk PE patients using FlowTriever thrombectomy in 84 patients and EKOS in 41 patients, with favorable outcomes.

EKOS Control Unit PT3B With Acoustic Pulse Thrombolysis
EKOS therapy uses ultrasonic waves in combination with clot-dissolving drugs to treat PE. With a sophisticated catheter and an ultrasonic core, the system effectively targets the entire clot (Figure 1). The new generation of the device (EKOS Control Unit 4.0) simplifies bilateral PE treatment with the following features: the ability to manage two EKOS devices at once with A/B channels and easy-to-read screens for bilateral PE acoustic pulse thrombolysis treatment; a portable size to easily integrate into the hospital workflow; faster setup time due to on-screen step-by- step prompts; on-screen troubleshooting that identifies where an issue is and how to correct it; and a built-in battery to transport patients from the lab without interrupting therapy.
The safety and efficacy of EKOS have been evaluated in several trials. ULTIMA was a prospective randomized controlled trial of 59 patients that showed superiority of EKOS over anticoagulation alone in RV/LV ratio reduction without an increase in bleeding.6 The prospective SEATTLE II trial (n = 150) confirmed that EKOS improved RV function, pulmonary hypertension, and clot burden without an increase in bleeding.2 The prospective, randomized controlled OPTALYSE trial (n = 101) used lower doses and infusion times for the treatment of acute PE without an increase in bleeding.7 The RV/LV ratio was reduced by 23% at 24 hours in ULTIMA, 25% at 48 hours in SEATTLE II, and 23% to 26% at 48 hours in OPTALYSE. All three trials demonstrated a low risk of bleeding and intracerebral hemorrhage (0% in ULTIMA, 10% in SEATTLE II, 3% in OPTALYSE). Results were achieved with 76% less thrombolytic drug dosage than standard treatment (total dose, 20 mg in ULTIMA, 24 mg in SEATTLE II, and 4/8 mg to 12/24 mg in OPTALYSE). The KNOCOUT PE retrospective and prospective registry (n = 1,500) is currently recruiting and aims to understand acoustic pulse thrombolysis treatment protocols and effects on long-term outcomes.

Bashir Endovascular Catheter
The Bashir endovascular catheter is an interventional tool that puts the control of the procedure directlyin the hands of the physician, who can control the expansion and contraction of the infusion basket from about 3 mm when closed and up to 45 mm in diameter when fully deployed (Figure 2). The device has a low- profile, 7-F design. It pulse sprays or infuses via 48 laser- drilled holes through the six limbs of the expandable infusion basket, and the Bashir endovascular catheter line also provides the ability to infuse along multiple lengths of catheter shaft together with the infusion basket. A unique aspect of this catheter-directed thrombolysis (CDT) device is the ability to create immediate blood flow through the culprit clot once the infusion basket is deployed, promoting rapid reperfusion and accelerated thrombolysis of the clot burden, saving time, and using a smaller lytics dose. A first-in-human (FIH) clinical trial to treat patients with acute submassive PE was completed in December 2019. The FIH trial met its primary endpoints with no major bleed events and no major adverse events. In addition, the trial demonstrated a significant mean reduction in the RV/LV ratio to 36.7% in 48 hours. There was a mean clot burden decrease of 37.1%, as measured with the Miller Index, after a mean dose of 13.6 mg of recombinant tPA over 8 hours. Patients treated with Bashir endovascular catheters had shorter intensive care unit (ICU) stays and overall stays compared with previously published studies in which CDT or mechanical thrombectomy devices were used to treat PE.
The success of this FIH trial led to FDA approval of the pivotal RESCUE trial. This single-arm study will treat patients with acute submassive PEs and is targeting 125 patients at 20 institutions. The protocol of RESCUE has been modified to reduce infusion time from 8 hours in the FIH to 5 hours in the RESCUE trial. The recombinant tPA dose will be limited to up to 14 mg for bilateral PEs.

THROMBECTOMY APPROACHES
PE cases are treated with thrombolytic therapy as a front-line standard of care. However, more aggressive catheter-based strategies may be useful when there is excessive clot burden, in hemodynamically unstable patients, and when thrombolytics are contraindicated or standard therapy fails. There are five catheter- directed techniques: ultrasound-assisted thrombolysis, rheolytic embolectomy, rotational embolectomy, aspiration thrombectomy, and thrombus fragmentation. Interventional thrombectomy is increasingly being used, and PE intervention is one of the fasting growing fields in endovascular intervention. Recent advances specific to PE have pushed the field forward, and the FDA is involved with study design to help promote product approval and allow quicker clinical access to new technology. There is no current standard of care for endovascular PE intervention, but the devices that are available are a dramatic improvement over previous technology.

Indigo Aspiration System
The Indigo aspiration system provides aspiration thrombectomy for acute PE (Figure 3). The EXTRACT PE trial revealed a 27.3% reduction in RV/LV ratio at 48 hours and a 1.7% major adverse event rate. There was a low procedure time (37 minutes) and on-table pulmonary artery pressure reduction. No thrombolytic drugs were used in 98.3% cases.1 CAT8, the newest iteration, allows for greater clot extraction and improved suction minimizing.

FlowTriever System
The FlowTriever thrombectomy system is designed for the removal of clot from the pulmonary arteries through both large-bore aspiration and mechanical retraction, without the need for thrombolytics (Figure 4). The FLARE trial was a prospective, multicenter, single-arm study that earned the FlowTriever system a PE-specific indication.3 The study met both of its primary safety and effectiveness endpoints, showing large and rapid reduction in right heart strain with no device-related major adverse events. The study also showed shorter ICU stay and overall length of stay for patients treated with FlowTriever compared to previous studies in which thrombolytic drugs were used

AngioVac System
The third-generation AngioVac system (AngioDynamics) includes a cannula with either a 20°- or 180°- angled tip (Figure 5), which potentially facilitates easier navigation through the pulmonary vasculature. It features a self- expanding, nitinol, funnel-shaped tip to enhance drainage flow when actuated using a sliding sheath and prevent clogging of the cannula with undesirable intravascular material (eg, thrombi, emboli, vegetation). Data from the second-generation AngioVac device showed the device to be safe and effective in removing caval thrombus, right atrial thrombus, cardiac lead vegetation, and tricuspid valve vegetations. The device is used off label for PE.

SUMMARY
Interventional treatment for PE has entered a rapid phase of evolution, with new devices becoming available on top of the transformational modification of first-generation devices. The data are inspiring but still lagging, and interventional guidelines need a universal standard. We need to continue to push for large data sets driven by consortiums/collaborations (such as the FLASH registry promoted by Inari Medical) to allow for thedevelopment of guideline-directed approaches. We have made great strides in endovascular PE therapy but have not quite found the holy grail. Several new devices are in the pipeline for PE treatment. Start-up companies such as Truvic are getting closer to “grail” status in peripheral vascular thrombus management by enabling single-session thrombus removal without the use of thrombolytics and with minimal blood loss by allowing access to proximal and distal clot with advanced catheter technology. Time will tell, but we are hopeful that these technologic advances will allow for dramatic clinical improvement and low periprocedural complications, thus broadening their use to all intermediate-risk PE patients. At this point, the decision to use CDT is based on the individual patient and their clinical scenario. Published literature supporting the effectiveness of CDT by clinical endpoints is still in development.

Better Overall Quality of Care and Efficiencies With a Fixed System in a Growing OBL

Originally Published in Cath Lab Digest, August 2020

The governor also issued a mandate to only do essential procedures, which we honored. What we found is that as Covid-19 continued to progress, a lot of patients sought out OBLs in an effort to avoid hospitals as much as possible. Due to the fear of Covid-19 spread, particularly in hot areas such as the hospitals, patients were requesting procedures to be done electively outside of the hospital, in facilities that have less chance of having Covid-19. At the peak of the Covid-19 spread, we established a Covid-free environment in our facility. We were able to do that because of a phased screening process for patients. It takes place initially over the telephone. Then at the entry into the building, patients are screened individually, one by one, while they are in the car and then screened when they enter the facility. We have been able to maintain a Covid-free environment. Since March — so, over the last four months — we have not had a single incident of a Covid-19 patient, staff, or physician in the facility.

Have patients expressed that they are worried about going to the hospital due to Covid-19?

Yes. There is an understandable fear of Covid-19, especially with those patients that do have peripheral disease and cardiovascular disease. These patients are at a higher risk of contracting Covid-19 and having related complications. Since they are high risk, they have to take all the necessary precautions, but these fears, among patients and physicians both, have also resulted in patients not being treated for heart disease, strokes, and other chronic illnesses, perhaps due to an extreme and unnecessary avoid- ance of care. Patients have a very reasonable fear of Covid-19, however, and to that end, the OBL serves a purpose, offering safety and service for the patient. In fact, because we did not know when the Covid-19 pandemic would end, at one point there was some discussion with Michigan’s governor and state health officials of converting OBLs into ambulatory surgical centers (ASCs) in order to do elective coronary procedures via the granting of a temporary license. Fortunately, the governor has done a good job controlling Covid-19 and we saw a decrease before having to execute this plan.

There has been ongoing discussion around expected new guidelines for ASCs regarding coronary angiography and intervention, with support from the Society for Cardiovascular Angiography and Interventions (SCAI). How do you see this market shift impacting the next 5 years?

OBLs and ACS has been very successful in provid- ing the same service as hospitals, but with greater efficiency, better patient satisfaction, and a quicker turnaround time, without having a bureaucracy. It is also a much more cost-effective method than going to the hospital. It is one of those scenarios where it’s a win-win for everyone. The patients are more satisfied. The insurance companies pay a lot less than they would in a hospital, because OBLs and ASCs don’t have the extensive overhead of hospitals. Operators work more efficiently and effectively with more controlled settings. The future of ASCs and OBLs is only going to expand. I envision in the next five years that we are going to be very similar to Texas and Florida, where most of these OBLs and acute ambulatory surgical centers will be doing coronary procedures. We anticipate the restrictions on performing coronary interventions will be lifted, and we predict that Michigan will follow Florida and Texas regulations. Covid-19 reinforced the desire for patients and physicians to have an alternative for hospital care. We foresee more OBL/ASCs opening in the near future and subsequently, a fixed system will be most beneficial to meet patient demand.

Can you tell us why you chose a fixed unit versus a mobile C-arm for your OBL?

We did extensive research before starting our OBL. My team and I visited different OBLs and ASCs throughout the country, from the East Coast to the West Coast to the South. We gathered as much data as we could in speaking to operators. After doing our research and looking at the economic impact of the project, we felt that our OBL, in the long term, would be better served with a fixed lab versus a C-arm. First and foremost, we wanted to not only replicate the hospital experience, but do even better than we would in the hospital, and hospitals have fixed labs. The future of coronary procedures is going to be outpatient and investing in a fixed lab prepares you for coronary angiograms. Simply upgrading the software will be a matter of hours in comparison to the extended time and investment for infrastructure changes that it takes to go from a mobile c-arm to a fixed lab. Paying up front for the fixed system is more efficient and cost effective for your overall return on investment. Another reason was integrity of patient care. We wanted to give the utmost in quality care to our patients, and we wanted to personalize care more than it would be at the hospital. The only way to do that is by utilizing the highest levels of technology and equipment to help the operator. We concluded that patient care, image quality, and the ability to maintain a larger patient volume population would be better served with a fixed lab. Our fixed lab (ARTIS zee angiography system, Siemens Healthineers) has the advantages of better imaging and acquisition, collimation, and road mapping, as well as other features that a mobile C-arm does not provide. There are also safety advantages, including less radiation for both the patient and the operator, and the ability to have filters. We can use collimation, there is reduced scatter, and the fluoroscopy is about one-third the dose of cine. These features in fixed labs allow you to reduce the amount of radiation by at least one third, with multiple added accessories that are not available with a C-arm. We felt that the lower cost of having a C-arm is really not as advantageous as it would seem, considering the safety applications available with a fixed lab. The final aspect is important from an efficiency perspective: better workflow and room efficiencies. We are able to complete cases more quickly and cost effectively with a fixed lab, while being safer, than with the use of a C-arm. Turnaround times are much quicker. One less staff member is necessary, because the controls of a fixed lab to pan can be used by a physician. Over an extended period of time, the lower costs from one less employee, as well as the efficiencies of a quick turnaround time, help offset the added cost of having the fixed lab.

How does a fixed lab differ from a mobile C-arm in terms of workflow?

Fixed units offer a larger area to image, so there is less movement required. The operator can maneuver the C-arm because the controls are adjustable and close to the operator, while still maintaining steril- ity. The controls are in the hand of the physician, so the physician is much faster in completing the procedure, because it’s not necessary to relay to the second operator what images or angles are desired. Turnaround is also very simple as far as the fixed lab, since the camera is designed to move out of the way to allow patients to maneuver on and off of the table, and it is very quick for adjusting the height and the angle of the table. When we did our calculations, we factored in the cost of added staff, the efficiencies of turnover, and the safety of the fixed lab versus a mobile C-arm. Our calculations showed that using a fixed lab in an OBL for less than two years meant it would not be a cost-effective investment. However, for any center that plans on being in business and serving patients for longer than two years, it is much more cost effective to have a fixed lab. We predict that cardiac cases in the near future, such as coronary angiograms, loop recorders, and pacemakers, will be performed as outpatient. Assuming that an OBL will provide service for greater than two years, the rate of return is much more effective with a fixed lab.

Are there specific functions and applications from Siemens that you appreciate in your fixed lab?

In terms of specific applications, Siemens offers a number of features with its Combined Applica- tions to Reduce Exposure (CARE) applications and CLEAR functions, which help enhance image quality. One of the most important features is Advanced Roadmap. As we are performing a procedure, we no longer have to use cine. The DSA Roadmap feature has helped us decrease radiation for both the operator and the patient due to the ability of using a digital subtraction angiography (DSA) image as a vessel roadmap. We have been able to cut the procedure time by at least 15%, because we are no longer using cine. We also have been able to cut the dosage of the contrast agent used for the procedure, because we are doing fewer images and the patient gets less exposure to contrast as a result. Another feature from Siemens is CO2-DSA, used for patients in whom we cannot administer contrast for various reasons, either due to chronic renal failure or a severe allergy to dye. We are able to obtain superior images that were not available prior to having this application. In the past, we had very rarely used CO2, because images were only enough to safely say that we could proceed with the procedure. With the use of the CO2-DSA application, we’ve had no restrictions. The images are very crisp and clear, and it has really changed our practice. Approximately 10% of our cases now incorporate use of the CO2 application without any use of IV contrast and produce very good images. We have also been able to integrate new technolo- gy. Siemens engineers were very helpful in integrat- ing intravascular ultrasound (IVUS) into our lab and it has become a common part of our practice. Now we can use IVUS with smaller sheaths; prior to all this, we had to use IVUS with larger sheaths. These advances have changed our practice model. Now we use IVUS to measure the lesion and also in sizing the vessel for possible intervention. We are also able to use IVUS when crossing chronic total occlusions to evaluate whether or not we are in the true lumen

Any final thoughts?

In planning our OBL, we considered five cath lab imaging companies. At our particular hos- pital, we work with five different vendors. After reviewing our experience, we felt that Siemens was probably the most user-friendly towards the operator and consistently dependable. One of the important things we considered when evaluating different vendors was the service agreement. We wondered how quickly each company would move if we experienced any issues with the equipment. The service agreement that we have with Siemens, and this is our experience in the hospital as well as in our OBL, has been outstanding. Siemens engineers are very quick to fix any problem that we have and when we tallied the amount of service that was required of different vendors over the last two years, the service for Siemens was much less than its competitors. They also offer a warranty that can be purchased with the fixed arm. Over the last two years, we have not needed the warranty, which is a testament to their good engineering.

Amir Kaki, interventional cardiologist, on what it's like to use the smallest heart pump to save lives

Originally Published in Crain’s Detroit Business, December 7th, 2020

Ascension St. John Hospital and Medical Center, Detroit: Recruited to Detroit in 2012 by Mike Duggan, the former CEO of Detroit Medical Center and now Detroit mayor, and Dr. Ted Schreiber, one of the nation's preeminent cardiologists, Dr. Amir Kaki, an interventional cardiologist and director of mechanical circulatory support at Ascension St. John, has always been at the cutting edge of heart medicine and now he is one of a handful of doctors in the U.S. who have inserted the world's smallest heart pump and the first for a COVID-19 positive patient suffering heart problems.

Born and raised in a small town in the southern Florida Everglades, Kaki completed his medical residency at the University of Tennessee, completed fellowships at the University of Arizona and at Lenox Hill Hospital in New York City. He was a faculty member at Cornell University when the call came from Schreiber, who also practices at Ascension

Another draw to Detroit is that his wife, Dr. Reema Hasan, a medical transplant doctor at Michigan Medicine in Ann Arbor, is a native Michigander. They have three children, two girls and a baby boy born in early November. In late November, after the interview was conducted, Kaki and his family contracted COVID-19 and are recuperating at home.

What is the story behind you and the Impella heart pump, which temporarily keeps the heart beating while undergoing various repair procedures?

I implanted my first pump in 2012 along with Dr. Mahir Elder in an initiative led by Dr. Ted Schreiber and Dr. Cindy Grines to deliver the highest quality cardiovascular care with cutting edge innovative care to the city of Detroit. Another local luminary in the field is Dr. Bill O'Neill at Henry Ford Hospital. Bill and Ted really kind of led the charge for this type of treatment for the very sickest patients in Southeast Michigan that resulted in the Detroit Cardiogenic Shock Initiative, a treatment that has transformed treatment across the world.

You also performed a heart operation using the Impella on a patient with COVID-19 at Ascension St. John in Detroit?

We had a patient present in the emergency room to Dr. Schreiber this past spring with COVID-19 and breathing problems at the height of the pandemic at Ascension Macomb- Oakland Hospital in Warren that turned out to be a large pulmonary embolism. When they did the ultrasound, we found she had a huge clot in the right side of her heart. There was no real way to get a clot out without some heroic measures. We brought her to St. John Hospital and put her on cardiopulmonary bypass. We were able to suck this clot out through her neck, but some of the clot that embolized made her PE worse. Then her right ventricular failed and we did emergency CPR until we put the Impella RP pump in. Based on our knowledge of those cases, we thought it'd be reasonable to put the pump in there to save her life. The patient survived and is doing very well. What we have found is that COVID-19 is thrombogenic, which means the coronavirus makes people clot. We actually did the first procedure on a Covid patient using the Impella RP like this. The FDA recognized the value and granted emergency use authorization in June.

How does the coronavirus affect the heart?

We have seen data from Asia, Europe and the U.S. that COVID-19 affects the heart in several ways. Coronavirus is an infection that often affects the lungs, filling air sacs with fluid and mucus, but it also can cause myocarditis, or inflammation of the heart muscle. A lot of the manifestations of the heart from coronavirus are on the right side because Covid patients are more likely to form blood clots from a pulmonary embolism arising from deep venous thrombosis or clots in the legs. About 10 percent to 20 percent of the patients we have seen at St. John have had some cardiac manifestations of Covid. As a result, more patients are getting blood thinners.

How is the Impella heart pump used?

The pump is used for elective procedures, what we call high risk PCI (percutaneous coronary intervention). It's also used for emergency situations in patients who have impending death present with cardiogenic shock, which have 50 percent survival rates without intervention. There are two uses for the pumps on the left side of the heart. It supports the patient transiently during the duration of the PCI, usually for 60 to 120 minutes. Or we put it in a patient who has profound cardiogenic shock. It often stays in for days to allow the heart to recover. If the heart does not recover, there are more advanced therapies such as durable LVAD (a left ventricular assist device) implanted permanently to act like a heart or heart transplantation.

You are involved in a small clinical trial to test the effectiveness of a new Impella pump model that is believed to be the world's smallest?

The FDA has mandated a safety study on five patients. So far we have completed successful operations on four patients and we have done the first and third here at St. John. After the fifth, the FDA will decide if it is safe to continue the trial with a larger group of up to 20 patients. I'm optimistic. The first patient was done Oct. 16 and the second was on Oct. 23. Both were very successful. The second patient did not want to undergo open heart surgery. We offered using the Impella and did a complete revascularization where we took out all three of his arteries successfully. He went home the next day and is doing wonderfully.

What is the improvement with the new Impella pump?

This one is much smaller, nearly half the size at the entry point. Anytime you can make these devices substantially smaller, you reduce the risk of vascular injuries. You also increase access for patients because the normal Impella sometimes is too big to fit and patients who have severe peripheral arterial disease can bleed from it. Now you have a device that can be much more broadly available for patients because it is three millimeters at the access point. Once it goes into the body, it expands. We are optimistic that within two years, assuming the research stands out, it will be safe and efficacious for patients and be commercially available.

DMC cardiologist pioneers system to treat pulmonary embolisms

Originally Published in Crain’s Detroit Business, January 15, 2017

Thousands of people have died over the years from what originally was believed to be a heart attack when the actual cause was a massive pulmonary embolism, said Mahir Elder, M.D., a top interventional cardiologist at Detroit Medical Center‘s Cardiovascular Institute who has developed a new diagnostic check for these serious kinds of emergency cases.

In the nation’s largest study of its kind, Elder and his Pulmonary Embolism Response Team (PERT) — also called the Clotbusters — have treated more than 250 patients the past two years for massive pulmonary embolisms with a lifesaving rate greater than 90 percent, far higher than the 42 percent save rate documented in other studies where patients received the blood-thinning drugs tPA or heparin.

“It started when I noticed a few cases in the (Detroit Receiving Hospital) ER back in 2012,” said Elder, who also is assistant director of the Wayne State University School of Medicine’s interventional cardiology fellowship program.

“PE can often be masked as MI (myocardial infarction, or heart attack),” said Elder. 
“It is often misdiagnosed, which can result in an unfortunate mortality. It is completely preventable if discovered promptly.”

Many ER physicians and other specialists don’t immediately diagnose the blood clot in the lung that is causing the emergency.

“A patient presents to the ED with difficulty breathing, short of breath and sharp chest pain, requiring oxygen therapy with low blood pressure (80/40 or less),” said Elder, a former Crain’s Health Care Hero.

“This requires quick action. Before, there was no standard way to treat it. No research, no procedure.”

Elder said reviews of national registries of unexplained deaths have shown that thousands of deaths were caused by massive pulmonary embolisms. This most usually happens when a blood clot dislodges from the leg and travels up into the lungs, blocking blood flow. This progresses to cardiac arrest, or a heart attack.
Each year, pulmonary embolisms kill at least 600,000 Americans, many of whom had no or little symptoms. It is one of the leading causes of sudden death.

In 2014, Elder received institutional review board approval from the Wayne State medical school and the DMC. His boss, Theodore Schreiber, M.D., president of the DMC Heart Hospital, was supportive of his plan to create the PERT team and institute the special PE guidelines in DMC Receiving’s emergency department. Schreiber is also on the PERT team.

“ER doctors will perform a cardiac ultrasound or CT scan of the lungs to confirm diagnosis (of PE). Once confirmed, the PERT team is activated,” said Elder, adding that the patient is then transferred to DMC’s catheterization lab at the Heart Hospital for an emergency procedure.

Elder, who is one of Michigan’s highest-volume operators of peripheral arterial disease and amputation prevention, said the approval process for PE guidelines was not easy.

“The naysayers (initially ER physicians, pulmonologists, vascular surgeons and interventional radiologists) were concerned that it may not work and there could be other options,” said Elder, who also is medical director of DMC Harper Hospital‘s cardiac care unit. “We won them over because we were saving lives. The ER doctors are very proud of what we did.”

The first step Elder needed was to develop the massive/submassive pulmonary embolism guidelines for the ER physicians to use in screening patients. The procedure algorithm is multifaceted, but begins with an initial patient evaluation. The guidelines recommend the patient be given 15 minutes of CPR.

For example, the patient presents with chest pains and other heart attack-like symptoms. ER doctors then order an IV, cardiac monitor and EKG, appropriate blood tests, CT angiogram or echocardiogram of the chest and heparin.
If the CT scan confirms symptoms of PE, ER doctors page a PERT team member and the patient is sent to the cath lab for an immediate procedure. DMC’s PERT team includes five interventional cardiologists, several fellows, nurses, cardiovascular technologists and radiology therapists.

Once the patient is in the cath lab and the PERT team is ready, Elder or another team cardiologist inserts a thin plastic tube (catheter) through a large vein in the patient’s groin area. The catheter tube is maneuvered through the patient’s circulatory system and deep inside the pulmonary artery close to the blood clot. Once in place, cardiologists break up the coagulated blood with ultrasound and inject anticlot medications.

“The procedure takes about 30 minutes and we are done,” Elder said. “It takes another four to six hours, depending on the size of the clot, to dissolve it.”
Technologies used for the procedure, known in the medical field as catheter-directed thrombolysis, were developed for other heart- and artery-related procedures. Elder’s team uses the EKOS Acoustic Pulse device.

“We use EKOS ultrasound to break up the fibrin clot, which is a web of strands that are connected together. Simultaneously, we use the anticlotting medication to dissolve it,” he said. The EKOS technology allows Elder and team to use much less blood thinner, which makes the procedure safer.

Under some extreme circumstances for highly unstable patients, Elder said, a small pump, the Abiomed Impella RP, is used to keep the heart going. “It is a temporary pump that decreases the pressure on the heart and offers circulatory support,” he said. “It is removed once the patient is stable.”

At first, Elder’s PERT team received referrals from DMC’s ER physicians and from the co-located Karmanos Cancer Institute.

“Now, pulmonologists, oncologists and surgeons with patients who develop PEs are seeing the benefit in our program” 24/7, Elder said.

Elder said DMC now has received referrals from several hospitals in Michigan, including patients who are airlifted from around the state.

Soon after Elder began researching options with PE, he discovered cardiologists at Massachusetts General Hospital were starting a similar program, and he called them to discuss options. He found they did not have a standard procedure. Since then, Massachusetts General has formed a national PERT consortium, which DMC has joined, to help spread the word at hospitals and with doctors.

To be successful, Elder said PERT teams must be inclusive and collaborative. They also must be able to quickly respond to PE cases. Mortality rates rise quickly as time passes, he said.

“We are ahead of Mass General. They have a team but not as efficient as us because we are in-house and open 24 hours a day, seven days a week, 365 days a year. They have a meeting first, then call in the team. It takes too long,” Elder said.

“Our hospital is the nation’s highest enroller in PE clinical research. We get more patients into the cath lab than anyone because we are here 24/7” through DMC’s Cardio Team One, he said.

Elder said having the PERT staff on call 24/7 is expensive, but after several years the service is now profitable. “You need at least 50 cases per year to be proficient,” he said.

But Elder said the ability to save lives makes it worthwhile for his team and the hospital.

“You should see them when they come into the ER. They are in very poor condition. They can’t breathe on their own and have a tremendous amount of chest pain. After the procedure, they are comfortable and they walk out of the hospital,” Elder said.
The majority of patients treated at DMC understand the importance of taking care of their health, Elder said. They hydrate, exercise and make sure they don’t sit too long without some form of movement, he said.

“About 90 percent of our patients make changes in their behavior, which significantly reduces the recurrence rates,” Elder said.

Physicians and nurses involved in the program are proud of what DMC Heart Hospital and Cardiovascular Institute are doing to prevent unnecessary deaths, he said.

“We treat massive PE better in Detroit than anywhere in the country,” Elder said. “We can say we are a world authority. We can say we are at the top in innovation and treatment for massive PE. We are proud of that.”

Benefiting from Pulmonary Embolism Response Teams