Pulmonary Embolism Response Teams: Structuring a Dedicated Provider Response to Improve Outcomes for Patients and Institutions

Pulmonary embolism (PE) is a major cause of morbidity and mortality and encompasses a wide range of clinical presentations.¹  In the recent past, the clinical presentations of patients with PE were commonly considered to be dichotomized as either massive or nonmassive, with treatment modalities chosen accordingly. This simplified categorization of PE resulted in a limited number of treatment options, typically routine systemic anticoagulation with heparinoids or systemic thrombolytic therapy. Recent evidence, however, shows that many patients may be candidates for more varied therapies based on their clinical histories and circumstances. More treatment options necessitate urgent, specialized expertise that can be employed at the earliest point in a patient’s clinical trajectory.

The introduction of better imaging techniques, biomarkers, and extensive correlations between clot burden and its clinical consequences has resulted in new paradigms for PE severity subcategorization beyond the previously used massive and nonmassive categories. Similarly, advancements in invasive-interventional medicine and systemic anticoagulation have introduced subtleties into choosing the best approach to each patient. Currently, there is a dearth of reliable comparative effectiveness studies aimed at defining which treatment is most beneficial for a given patient. Yet the mortality rate for patients with massive PE remains high.^2-4  The complexity of patients with PE and the diverse clinical impact of their PE burden have left much of the clinical decision making to expert consensus rather than to rigorously vetted scientific guidelines. As a result, treatment approaches may be inconsistent and uncoordinated without a centralized location of care or systematic way to evaluate response to therapy.

Historically, medical institutions have responded to disorders of urgent dire consequences with multidisciplinary teams capable of immediate assembly and response. Akin to Code and Stroke Teams, newer techniques for the assessment and treatment of acute PE patients have led to the emergence of pulmonary embolus response teams (PERT). One of the first introductions of a multidisciplinary PERT was presented by Massachusetts General Hospital (MGH) in a publication in Chest in November 2013.⁵  Since then, institutions around the world have developed PERTs with the immediate goal of coordinating care and improving outcomes by assembling a multidisciplinary team of experts to discuss, deliberate, determine, and implement the most appropriate therapeutic option for each patient with PE.

Although the provider makeup of each PERT may differ,^6,7  teams should typically include physicians with expertise in the medical care of patients with PE, pulmonary imaging, and interventional medicine, and have immediate access to cardiothoracic surgery and circulatory support systems. PERTs develop differently to take advantage of locally available resources and to suit local clinical demands. At MGH, for example, a referring physician calls a 24-hour hotline, which triggers an immediate consultation by the PERT fellow who then, with direct involvement of an attending physician, performs the initial patient evaluation and assesses the severity of the case. If appropriate, an online meeting of the entire team (which may include pulmonary/critical care, interventional and noninterventional cardiology, vascular medicine, vascular surgery, emergency medicine, hematology, interventional radiology, cardiac surgery, pharmacy, and radiology) convenes to review the case, laboratory tests, and radiographic images. If advanced interventions are warranted, the multidisciplinary team then generates further diagnostic and treatment recommendations and assembles the appropriate resources. PERT assembly ultimately results in the most appropriate formal or informal coordinated treatment pathways for a specific patient population and based on that institution’s capabilities. Any PERT program requires an infrastructure that allows for the rapid and efficient communication of specialists who contribute vital information about a patient’s clinical situation.^8,9 

Importantly, the incorporation of residents and fellows into the PERT provides an excellent opportunity for trainees to work with experts in the treatment of PE. Frequent discussion about the interpretation of images, biomarkers, and other assessment of patients lead to further refinement of trainees’ skills. Additionally, participating in the PERT’s immediate response allows the trainees to appreciate the variabilities in patient presentation relative to the more objectively-determined disease severity. With arrangements for long-term follow up within the PERT, trainees also have an opportunity to assess the patient during recovery to investigate the etiology of the PE, guide decisions around anticoagulation management, screen for long-term complications of PE, and ensure removal of an inferior vena cava filter (IVCF) if present. A recent study evaluating the effect of a multispecialty team for high-risk PE on resident and fellow education found that when comparing pre- and post-PERT implementation, trainees were more confident in identifying and managing submassive and massive PE and in treating patients appropriately with systemic thrombolysis. Additionally, data showed they demonstrated increased knowledge of indications for systemic thrombolysis and surgical embolectomy. Trainees reported increased knowledge of high-risk PE pathophysiology and the perception that a multidisciplinary team improves care of patients.¹⁰ 

The presence of a PERT may also further the education of attending physicians, many of whom are not directly involved in interventional medicine and have limited knowledge of the types of treatments available for patients with PE beyond “systemic” or “catheter-directed” lysis (CDT) or thrombectomy. Similarly, many interventionalists may be unfamiliar with all the new and emerging anticoagulant options. PERT assessment of patients with PEs of submassive or worse severity demands that the team consider the patients’ candidacy for invasive interventions such as CDT or IVCF placement, as well as determine the type, duration, and intensity of anticoagulation. Furthermore, it remains unknown whether newer targeted oral anticoagulants are equally effective in circumstances in which patients have experienced a PE (e.g., after thrombectomy or with intravascular stents, thromboembolic pulmonary hypertension, or lupus anticoagulant–associated venous thromboembolism). Thus, as each PERT matures, these same issues should be evaluated on a broader scale and may be included in the PERT consensus or in local clinical pathways. These repeated processes ensure that PERT members are aware of the advantages and disadvantages of specific brands and types of interventional devices and anticoagulants available at each institution. The establishment of a formal consensus by a PERT provides an incentive for the consequences of each step of a clinical pathway to be periodically assessed and for the pathway to be appropriately modified.

The relatively new appearance of PERTs in the medical landscape provides fertile ground for disseminating information and applying new techniques both faster and more appropriately at medical institutions of various sizes and missions. The relative uniformity of their design and implementation also provides a template for data gathering and performance of prospective research regarding innovative devices and other medical interventions. A few reports from institutions currently detail the potential value of PERT, including the first 30-month experience from MGH that found that the PERT paradigm was rapidly adopted, with the number of activations increasing 16 percent every six months.¹¹  Reports from Cleveland Clinic and New York University similarly demonstrated  that a multidisciplinary approach to cases of intermediate- and high-risk PE can be implemented successfully and that activations increased over time.^12,13  These studies also suggest that PERT facilitates access to advanced therapies. A recent interrupted time-series analysis demonstrated an increase in the proportion of PE patients undergoing any advanced therapy, from 9 percent to 19 percent, after the introduction of a PERT.¹⁴  This increase was attributed largely to greater use of CDT, which grew from 1 percent to 14 percent. Importantly, even with an increase in advanced therapies following the implementation of a PERT, this analysis suggested a downtrend in both bleeding and mortality.¹⁴  More research is needed to confirm the effectiveness of PERTs and, in particular, to determine if PERTs and the therapies they recommend improve clinical outcomes. Additionally, the benefits and effectiveness of PERTs regarding cost and patient quality of life need further investigation.

In 2015, a small number of these multidisciplinary teams convened in Boston to form the National PERT Consortium to advance the diagnosis, treatment, and outcomes of patients with life-threatening PEs. Since then, the consortium has gained members from Europe, China, Saudi Arabia, and South America, with more than 75 institutions and more than 1,500 members joining. Its vision is to guide and influence PE care worldwide through education, research and clinical guidelines. The consortium created a framework of committees (governance, research, education, clinical practice and protocols, development, and communication) to support the infrastructure and resources for the advancement of PE care and the establishment of multicenter partnerships.

Despite recent advances in the assessment and treatment of PE, a general lack of consensus regarding the best approach to patients with submassive PEs and long-term therapy for all patients with PEs remains. The assembly of a PERT offers a way to expeditiously and simultaneously engage multiple experts to generate a thoughtful, coordinated, and comprehensive treatment plan for patients with PE. Studies highlight many ways to form PERTs, while the PERT Consortium provides a forum for various institutions to exchange views, educate one another and the public, and set up treatment guidelines and protocols. If interested in learning more about establishing a PERT at your institution or joining the PERT Consortium, please visit www.pertconsortium.org.