From PERT to AI, high-risk PE care evolves


In 2012, a small group of specialists, consisting of a critical care pulmonologist, cardiologist, cardiac surgeon, and vascular specialist, at Massachusetts General Hospital, Boston, met to Monday morning quarterback an acute pulmonary embolism case that didn’t go as well as they’d hoped. They came up with a concept known as the pulmonary embolism response team – PERT for short – an idea that soon took hold in other centers and served as the vanguard to other innovative approaches to managing critical care patients with PE, which is the third-leading cause of cardiovascular death in the United States (Intern Emerg Med. 2023. doi: 10.1007/s11739-022-03180-w).

The PERT team at the University of Michigan led by cardiac electrophysiologist Fred Morady, MD, performing catheter-directed thrombolysis. Leisa Thompson/Michigan Medicine

The PERT team at the University of Michigan led by cardiac electrophysiologist Fred Morady, MD, performing catheter-directed thrombolysis.

Three years later the PERT Consortium came together, which today has 102 members, according to the organization’s website (www.pertconsortium.org), and members in South America, Europe, Asia, and Australia. Since then, PE strategies have evolved to target mental health issues recovering patients have, improve follow-up after discharge, and even investigate artificial intelligence and apps to expedite diagnosis and treatment. The PERT Consortium, meanwhile, is in the process of creating the PE Centers of Excellence program to certify centers that meet certain requirements.

Christopher Kabrhel, MD, MPH, director of the Center for Vascular Emergencies at Massachusetts General Hospital and a professor at Harvard Medical School in Boston Harvard Medical School

Dr. Christopher Kabrhel

“Part of the reason we recognized that a discussion across specialties was important was because there weren’t the large clinical trials that could tell us exactly what to do for any given case,” said Christopher Kabrhel, MD, MPH, director of the Center for Vascular Emergencies at Mass General and a professor at Harvard Medical School in Boston, who assembled that formative meeting. “Without a clear basis in data, it was really important to have all the different specialists weigh in and give their perspective and talk about what was the best approach for the patient’s care.”

Filling data gaps

Some of those data gaps persist today, Dr. Kabrhel said. “It’s precisely that lack of head-to-head data that existed in 2012, and to a great extent still exists today, that led us to create this system.” The American Heart Association just this January issued a scientific statement on surgical management and mechanical circulatory support in high-risk PE (Circulation. 2023;147:e628­­-47).

But the intervening research has been uneven. The Pulmonary Embolism Thrombolysis (PEITHO) trial in 2014 evaluated systemic thrombolysis and anticoagulation alone (N Engl J Med. 2014;370:1402-11), but head-to-head studies of catheter-directed thrombolysis (CDT), which was just emerging in 2012, and either systemic thrombolysis or anticoagulation have been lacking, Dr. Kabrhel said. The Hi-PEITHO trial in high-risk PE patients is evaluating ultrasound-guided CDT plus anticoagulation vs. anticoagulation alone (Am Heart J. 2022:251:43-54), but it isn’t complete.

“The therapeutic landscape for PE is evolving incredibly rapidly,” he said. “When we first started PERT we were just starting to see CDT. Since then, we’ve seen several new thrombolytic catheters come onto the market, but there’s also been a proliferation of suction embolectomy catheters and we’ve seen a potentially larger role for surgery and the use of ECMO [extracorporeal membrane oxygenation] or cardiac bypass to bridge patients to definitive therapy. With the rapid evolution and the seemingly daily addition of new therapeutic options, I think the need for PERT is only increasing.”

A recent study out of the University of Michigan reported that the PERT there led to a decrease in the use of advanced therapies given to acute PE patients without reducing mortality or extending hospital stays (Thromb Res. 2023;221:73-8). A study in Spain reported that patients with high-risk and intermediate high-risk PE who had PERT-coordinated care had half the 12-month mortality rate of non-PERT counterparts, 9% vs. 22.2% (P = .02) (Med Clin [Barc]. 2023;S0025-7753(23)00017-9). And a 2021 study at University Hospitals in Cleveland reported that PERT-managed PE patients had a 60% lower rate of adverse outcomes at 90 days than non–PERT-managed patients (J Invasive Cardiol. 2021;33:E173-E180).

Nelish Ardeshna, MD, MA, internal medicine resident, University of Michigan, Ann Arbor Michigan Medicine

Dr. Nelish Ardeshna

Nelish Ardeshna, MD, MA, the lead author of the Michigan study, said the PERT there was formed in 2017. Besides the multispecialty team that can be summoned to a teleconference on short notice, the protocol includes having at least one noninvasive specialist, such as a cardiologist or hospitalist, and one interventionalist, such as a radiologist, always on call. The PERT gets activated through the paging system after a hospital or emergency department physician identifies a suspected or established high-risk PE.

“High-risk PE patients can present in all settings, including the emergency department, ICU, surgical floor, or medical floor,” said Dr. Ardeshna, an internal medicine resident. “Management for these patients is equally varied from anticoagulation to systemic thrombolytics. Not all providers may be familiar with current guidelines to select the optimal therapy for high-risk pulmonary embolism patients. PERT aims to bridge that gap by providing a multidisciplinary discussion with PE specialists that can help identify the correct therapeutic options for optimal outcomes.”

Leben Tefera, MD, is a vascular medicine specialist at the Robert and Suzanne Tomsich Department of Cardiovascular Medicine Heart and Vascular Institute, Cleveland Clinic. Cleveland Clinic

Dr. Leben Tefera

At Cleveland Clinic, where the PERT has been in place since 2012, the PERT can consist of six to eight different specialties and involve up to 15 providers on a conference call, said Leben Tefera, MD, a vascular specialist and head of the PERT team there.

“Each patient will come in and have certain comorbidities,” Dr. Tefera said. “The unfortunate thing about a majority of the PEs that we see, in particular ones [in patients] that are very sick and require inpatient treatment, is that they don’t really fit into a box; you can’t come up with one kind of generic care routine or care path that treats the majority of patients with PE.”


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