The Pulmonary Embolism Response Team: Rationale, Operation, and Outcomes

Multidisciplinary Approach to Pulmonary Embolism and the Role of the Pulmonary Embolism Response Team

PURPOSE OF REVIEW

Acute pulmonary embolism (PE) is a leading cause of cardiovascular death and morbidity, and presents a major burden to healthcare systems. The field has seen rapid growth with development of innovative clot reduction technologies, as well as ongoing multicenter trials that may completely revolutionize care of PE patients. However, current paucity of robust clinical trials and guidelines often leave individual physicians managing patients with acute PE in a dilemma.

RECENT FINDINGS

The pulmonary embolism response team (PERT) was developed as a platform to rapidly engage multiple specialists to deliver evidence-based, organized and efficient care and help address some of the gaps in knowledge. Several centers investigating outcomes following implementation of PERT have demonstrated shorter hospital and intensive-care unit stays, lower use of inferior vena cava filters, and in some instances improved mortality. Since the advent of PERT, early findings demonstrate promise with improved outcomes after implementation of PERT. Incorporation of artificial intelligence (AI) into PERT has also shown promise with more streamlined care and reducing response times. Further clinical trials are needed to examine the impact of PERT model on care delivery and clinical outcomes.

Diagnostic Strategies in Pulmonary Embolism

Key to the diagnosis of pulmonary embolism (PE) is a careful bedside evaluation. After this, there are three further diagnostic steps. In all patients, estimation of the clinical probability of PE is performed. The other two steps are measurement of D-dimer when indicated and chest imaging when indicated. The clinical probability of PE is estimated at low, moderate, or high. The prevalence of PE is less than 15% among patients with low clinical probability, 15 to 40% with moderate clinical probability, and >40% in patients with high clinical probability. Clinical gestalt has been found to be very useful in estimating probability of PE. However, clinical prediction rules, such as Wells criteria, the modified Geneva score, and the PE rule out criteria have been advocated as adjuncts. In patients with high clinical probability, the high prevalence of PE can lower the D-dimer negative predictive value, which could increase the risk of diagnostic failure. Consequently, patients with high probability for PE need to proceed directly to chest imaging, without prior measurement of D-dimer level. Key studies in determining which low to moderate probability patients require chest imaging are the Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism (ADJUST-PE), the Simplified diagnostic management of suspected pulmonary embolism (YEARS), and the Pulmonary Embolism Graduated D-Dimer trials. In patients with low clinical probability, PE can be excluded without imaging studies if D-dimer is less than 1,000 ng/mL. In patients in whom there is not a low likelihood for PE, this can be excluded without imaging studies if the D-dimer is below the age-adjusted threshold.

Role of Extracorporeal Membrane Oxygenation in the Treatment of Massive Pulmonary Embolism

Massive/high-risk pulmonary embolism (PE) is associated with a 30-day mortality rate of approximately 65%. In searching for strategies that may make a dent on this dismal mortality rate, investigators have, over the last decade, shown renewed interest in the potential beneficial role of venoarterial (V-A) extracorporeal membrane oxygenation (ECMO) in the treatment of patients with high-risk PE. There is a dearth of high-quality evidence regarding the value of ECMO in the treatment of massive PE. Studies examining this issue have generally been retrospective, often single center and frequently with small patient numbers. Moreover, these reported studies are not matched with appropriate controls, and, accordingly, it is difficult to regulate for inherent treatment bias. Not surprisingly, there are no randomized controlled trials examining the value of ECMO in the treatment of massive PE, as such trials would pose formidable feasibility challenges. Over the past several years, there has been increasing support for upfront use of V-A ECMO in the treatment of massive PE, when it is complicated by cardiac arrest. In those patients without cardiac arrest, but who have contraindications for thrombolysis, V-A ECMO combined with anticoagulation may be used to stabilize the patient. If after 3 to 5 days, such patients demonstrate persistent right ventricular dysfunction, embolectomy (either surgical or catheter based) should be performed. Well-designed, multicenter, prospective studies are urgently needed to better define the role of V-A ECMO in the treatment of patients with massive PE.

Management of high and intermediate-high risk pulmonary embolism: A position paper of the Interventional Cardiology Working Group of the Italian Society of Cardiology

Pulmonary embolism (PE) is a potentially life-threatening condition that remains a major global health concern. Noteworthy, patients with high- and intermediate-high-risk PE pose unique challenges because they often display clinical and hemodynamic instability, thus requiring rapid intervention to mitigate the risk of clinical deterioration and death. Importantly, recovery from PE is associated with long-term complications such as recurrences, bleeding with oral anticoagulant treatment, pulmonary hypertension, and psychological distress. Several novel strategies to improve risk factor characterization and management of patients with PE have recently been introduced. Accordingly, this position paper of the Working Group of Interventional Cardiology of the Italian Society of Cardiology deals with the landscape of high- and intermediate-high risk PE, with a focus on bridging the gap between the evolving standards of care and the current clinical practice. Specifically, the growing importance of catheter-directed therapies as part of the therapeutic armamentarium is highlighted. These interventions have been shown to be effective strategies in unstable patients since they offer, as compared with thrombolysis, faster and more effective restoration of hemodynamic stability with a consistent reduction in the risk of bleeding. Evolving standards of care underscore the need for continuous re-assessment of patient risk stratification. To this end, a multidisciplinary approach is paramount in refining selection criteria to deliver the most effective treatment to patients with unstable hemodynamics. In conclusion, the current management of unstable patients with PE should prioritize tailored treatment in a patient-oriented approach in which transcatheter therapies play a central role.