Catheter-directed therapy in intermediate-high risk pulmonary embolism: which predictive factors for a favorable therapy response?

Background Intermediate-high risk pulmonary embolism (IHRPE) is associated with worse outcomes. The place of catheter-directed therapy (CDT) is growing but data remains sparse to identify the best patient profile1–7. Purpose To evaluate the efficacy and safety of CDT in routine clinical practice and to identify predictors of a favorable clinical response. Methods Consecutive IHRPE patients defined according to ESC guidelines8 (elevated cardiac biomarkers associated with right ventricular involvement and initial hemodynamic stability) were included between January 2023 to January 2025 from two French university hospitals. Patients were divided into two groups based on the therapy they received, a conventional group (anticoagulation therapy alone) and a CDT group (anticoagulation therapy combined with one of the two percutaneous pulmonary reperfusion techniques available, either the large-bore mechanical thrombectomy system FlowTriever™ or the ultrasound-assisted catheter-directed thrombolysis system EKOS™ Endovascular System). All patients were followed during hospitalization using clinical, imaging and biological variables. The primary endpoint was the achievement of a “favorable therapy response” defined as oxygen therapy weaning, halving of cardiac biomarkers (troponin and/or Nt-ProBNP) and lactate clearance. Results Among the 126 patients included, 75 patients were assigned to the CDT group and 51 to the conventional one. Those in the CDT group appeared to be more severely affected based on baseline clinical, biological and imaging findings. Procedural success was achieved in 96% of patients of the CDT group. With respect to the primary endpoint, 22 patients (76%) in the conventional group, versus 35 (73%) in the CDT group met the criteria for a “favorable therapy response” with no significant difference (p = 0.775, OR 1.17 [0.41 – 3.31]). However, a ≥50% reduction in NT-proBNP occurred more frequently in the CDT group (81% vs 56%, HR 3.44, 95% CI 1.23–9.58; p = 0.015). Normalization of right ventricular function was also more frequent in the CDT group, although the difference did not reach statistical significance (80% vs 56%, p = 0.19). Nevertheless, there was no significant difference in oxygen weaning or time to oxygen weaning, in the reduction of RV diameter, reduction of the RV/LV ratio or MILLER II CT obstruction score9. Regarding safety outcomes, clinically relevant bleeding (BARC10 ≥ 2) was significantly more frequent in the CDT group (24% vs 10% (p = 0.043)), mainly driven by puncture-site hematoma (50%) and blood transfusions (22%). The mortality rate was particularly low with an overall mortality of 5%. Conclusion With a high technical success rate and safe procedure, CDT demonstrated an advantage in halving Nt-proBNP compared to anticoagulation therapy alone at the cost of a higher risk of clinically relevant bleeding. Further data are awaited to try to confirm this effect on hard clinical outcomes.