Prospective Multicentric Evaluation of PERT in treatment of Pulmonary Embolism: Composition, Utilization, and Impact on Clinical Outcome

Introduction: Pulmonary embolism (PE) is a cardiovascular disease with an increase in its incidence worldwide. Given the advancement in catheter-directed treatment, the current ESC guidelines were already complemented by a consensus paper with recommendations concerning interventional PE treatment. Herein, the importance of individualised decision-making through a multidisciplinary Pulmonary Embolism Response Team (PERT) is emphasised. Our study assesses the impact of established PERTs at two major university hospitals and analyses the clinical outcomes of various treatment strategies.

Methods: We conducted a prospective, multicenter observational study encompassing all patients referred to the PERT at University Hospital Cologne and University Hospital Mainz between 07/2023 and 03/2024. Patients with intermediate-high or high-risk PE were included. The PERTs were variably composed but typically included specialists from cardiology, radiology and intensive care medicine, with contributions from cardiothoracic surgery and other disciplines as needed. Treatment decisions were made based on ESC guidelines and consensus papers, encompassing anticoagulation, systemic thrombolysis, catheter-directed treatment such as mechanical thrombectomy [CBT] using the FlowTriever system, ultrasound-assisted catheter-supported lysis therapy [CDT] using the EKOS system, and surgical intervention for thrombi in transit. Right heart strain (RHS) on transthoracic echocardiogram was assessed using key findings (RV dilatation, RV>LV, D-sign, paradoxical septal movement, apex-forming RV) summed up to create an ordinal value.

Results: A total of 174 patients were included in our study. In 101 patients treatment was conservatively with heparin only, 24 patients were treated with systemic thrombolysis, 46 by using catheter-directed treatment (34 CBT and 12 CDT), and 3 patients underwent surgical embolectomy. Patients treated with catheter-directed treatment or systemic thrombolysis had a higher estimated risk according to ESC risk stratification and PESI (PESI mean ≥133±42 and 147±43, respectively; ESC high risk in 36% and 79%, respectively). Accordingly, mortality (20% for catheter-directed treatment and 50% for systemic thrombolysis) was higher than in the conservative group (12%). There were no treatment-related deaths. Bleeding complications occurred in 9% for catheter-directed treatment and 13% for systemic thrombolysis. In the group of catheter-directed treatment, no bleeding was procedure-related, yet there were two CBT-related complications (self-limited pulmonary hemorrhage in a patient after breast cancer and radiotherapy; paradoxical embolism in PFO diagnosed postinterventional). 

With regard to RHS, there was a significant reduction between admission and discharge only in the catheter-directed treatment (p< .001) and systemic thrombolysis group (p .021). In comparison to the conservative group, there was a significantly lower incidence of RHS at discharge after catheter-directed treatment (p .044).

Discussion: Acute PE continues to be associated with a high mortality, particularly in the intermediate-high and high-risk group. Catheter-directed treatment, either CDT or CBT, appears to be safe to use and effective, and seems to lead to a swift improvement of right heart function. Our study suggests that PERT implementation at high-volume centers facilitates multidisciplinary collaboration, potentially optimizing treatment pathways for complex PE cases.