Evolution of Acute Pulmonary Embolism Management
Acute pulmonary embolism (PE) remains a significant cause of cardiovascular morbidity and mortality worldwide. Historically, management strategies were largely binary: systemic anticoagulation for hemodynamically stable patients and systemic thrombolysis or surgical embolectomy for those with massive, life-threatening obstructions. However, the emergence of the ‘intermediate-risk’ or ‘submassive’ PE category has created a clinical gray area where the risks of systemic thrombolysis—most notably intracranial hemorrhage—often outweigh the perceived benefits. This clinical challenge necessitated a more nuanced approach, leading to the development of Multidisciplinary Pulmonary Embolism Response Teams (PERT) and a burgeoning interest in catheter-directed therapies (CDT).
As these specialized teams have become more prevalent, the landscape of PE treatment has shifted. Clinicians are now equipped with a diverse array of interventional tools, ranging from ultrasound-assisted thrombolysis to large-bore mechanical thrombectomy. Despite this rapid technological expansion, real-world data on how these treatments are being utilized and their subsequent impact on patient outcomes compared to standard care have been limited. The recent analysis of the PERT Consortium registry provides essential insights into these trends and the clinical efficacy of a multidisciplinary, interventional approach.
The Role of Multidisciplinary Pulmonary Embolism Response Teams (PERT)
The PERT model was designed to bring together experts from cardiology, pulmonology, critical care, radiology, and vascular surgery to provide rapid, evidence-based decision-making for complex PE cases. By leveraging the collective expertise of various disciplines, PERTs aim to tailor interventions to the specific hemodynamic and anatomical needs of the patient. The growth of the PERT Consortium, a multicenter national quality assurance database, has allowed for the systematic collection of prospective data, offering a window into the evolving standard of care across high-volume centers.
Study Methodology: Comparing Real-World Registry Data with National Standards
This study analyzed data from the prospective multicenter PERT Consortium registry, spanning from 2018 to 2024. The cohort included 11,436 patients enrolled at 51 sites. The median age of the participants was 65 years, with a distribution of 13.7% high-risk (massive) and 62.5% intermediate-risk (submassive) PE.
The primary focus of the analysis was the utilization of catheter-directed treatments (CDT), which included catheter-directed thrombolysis (with or without ultrasound assistance) and mechanical thrombectomy or aspiration. To provide a meaningful benchmark for outcomes, the researchers utilized an age-, sex-, and PE risk-matched population from the US Nationwide Inpatient Sample (NIS). This comparison allowed the investigators to evaluate whether the specialized care provided within PERT-participating institutions translated to superior clinical results compared to the broader national average.
Shift in Treatment Paradigms: The Rise of Mechanical Thrombectomy
One of the most striking findings of the study was the significant increase in the use of CDT over the six-year period. Of the 11,436 patients, 2,639 (23.1%) underwent some form of catheter-based intervention. However, the composition of these interventions changed dramatically over time.
Mechanical Thrombectomy vs. Catheter-Directed Thrombolysis
Linear regression analysis revealed a quarterly increase of 0.36% in the overall use of CDT (P=0.002). Within the CDT category, mechanical thrombectomy/aspiration emerged as the dominant modality, increasing by 0.83% per quarter (P<0.001). Conversely, the use of catheter-directed thrombolysis (CDT-L) showed a significant decrease of 0.4% per quarter (P=0.001). By the end of the study period, mechanical thrombectomy accounted for 58.1% of all CDT procedures, while ultrasound-assisted thrombolysis was used in 32.2% and non-ultrasound catheter thrombolysis in only 5.3%.
This shift reflects a growing clinical preference for 'thrombus removal' over 'thrombus dissolution.' Mechanical thrombectomy offers several theoretical advantages, including the immediate reduction of right ventricular afterload and the avoidance of fibrinolytic agents, which is particularly critical for patients with recent surgery, trauma, or high bleeding risk. The data suggest that as devices have evolved and clinical experience has grown, the interventional community is moving away from drug-based catheter therapies in favor of purely mechanical solutions.
Other Advanced Therapies
Despite the rise of CDT, other advanced therapies remained relatively stable or were used in highly specific scenarios. Systemic thrombolysis was utilized in 5.6% of all patients, surgical embolectomy in 1.1%, and extracorporeal membrane oxygenation (ECMO) in 1.6%. These figures highlight that while CDT is becoming a cornerstone of management, there remains a subset of patients who require systemic treatment or surgical intervention.
Clinical Outcomes: Lower Mortality and Shorter Length of Stay
The most clinically significant aspect of the study was the comparison between the PERT Consortium registry and the NIS population. After matching 10,883 patients from the registry to their counterparts in the national sample, several key differences emerged:
1. CDT Utilization: There was a 22% (95% CI, 21-23%) standardized mean difference in the use of CDT, indicating that patients managed within the PERT framework were significantly more likely to receive advanced interventional therapy than those in the general NIS population.
2. In-Hospital Mortality: Patients in the PERT registry experienced a 1.3% (95% CI, 0.6-2.0%) lower in-hospital mortality rate compared to the matched NIS cohort.
3. Hospital Length of Stay: The PERT group had a shorter hospital stay by an average of 0.75 days (95% CI, 0.2-1.3 days).
These findings suggest that the multidisciplinary oversight and the increased use of catheter-directed therapies in PERT-capable centers are associated with tangible improvements in survival and healthcare efficiency. The reduction in mortality is particularly noteworthy, as it suggests that the prompt identification and interventional management of high- and intermediate-risk PE can save lives that might otherwise be lost under conventional management strategies.
Expert Commentary: Interpreting the Data
The results of this registry analysis align with several emerging themes in cardiovascular medicine. The transition toward mechanical thrombectomy is likely driven by both the speed of hemodynamic improvement and the safety profile regarding major bleeding. In many centers, the ‘first-line’ interventional approach for submassive PE with evidence of right ventricular strain is now large-bore aspiration thrombectomy.
However, it is important to consider the potential for selection bias. Centers that participate in the PERT Consortium are often academic or high-volume tertiary care facilities with specialized expertise and infrastructure. Therefore, the improved outcomes observed may not only be due to the specific interventions (CDT) but also the high level of supportive care, specialized nursing, and the collective experience of the multidisciplinary team.
Furthermore, while the 1.3% absolute reduction in mortality is statistically significant, it prompts questions about which specific patient phenotypes benefit most from CDT. The registry data indicates that over 60% of the patients were intermediate-risk; determining which of these patients are ‘intermediate-high risk’ and most likely to deteriorate without intervention remains a critical task for clinical research.
Conclusion: Shaping the Future of PE Care
The analysis of the PERTTM Consortium registry provides robust evidence that the management of acute pulmonary embolism is undergoing a significant transformation. The increasing adoption of catheter-directed therapy, particularly mechanical thrombectomy, is a defining trend of the current era. More importantly, the association between management in a PERT-focused environment and lower in-hospital mortality suggests that the multidisciplinary model is effective.
As we move forward, the challenge will be to standardize these specialized approaches and ensure that the benefits of PERT and advanced interventional therapies are accessible to a broader patient population. Future research should focus on long-term outcomes, such as the incidence of chronic thromboembolic pulmonary hypertension (CTEPH) and quality of life, to fully understand the impact of early mechanical intervention.
References
Farmakis IT, Horbal S, Moriarty JM, Elder M, Todoran T, Rosovsky RP, Lehr E, Langston MD, Sokol SI, Rosenfield K, Lookstein R, Secemsky E, Christodoulou KC, Hobohm L, Valerio L, Barco S, Konstantinides SV. Trends in Catheter-Directed Therapy and In-Hospital Outcomes Among Patients with Acute Pulmonary Embolism: Insights from a Multicenter National Quality Assurance Database Registry. Eur Heart J Acute Cardiovasc Care. 2025 Dec 23:zuaf169. doi: 10.1093/ehjacc/zuaf169. Epub ahead of print. PMID: 41432497.