A Randomized Pilot Trial Comparing Combined Catheter-Interventional Treatment Versus Standard of Care in Intermediate High-Risk Pulmonary Embolism

Background: Catheter-directed treatment of pulmonary artery embolism (PE) is increasingly used worldwide. Numerous devices for mechanical thrombectomy (MT) and local fibrinolysis (LF) have become available over recent years. While various studies show safety and efficacy for either MT or LF, little is known about the combination of both treatment modalities. Aims: This open-label, single-center, randomized controlled pilot trial aimed to investigate the treatment effect size and safety of a combined catheter-interventional treatment (CCIT) approach for PE, consisting of LF and MT in comparison to conventional guideline-directed therapy. Methods: Twenty patients with intermediate-high risk PE were randomized 2:1 to CCIT or control. The two co-primary endpoints were the difference in (1) a combined clinical endpoint (consisting of systolic blood pressure over heart rate, and respiratory rate) and (2) right-to-left ventricular (RV/LV)-ratio from a transthoracic echocardiogram between the two groups 24 h after randomization. Results: After 24 h, the combined clinical endpoint improved by 0.02 ± 0.01 in the CCIT group, whereas no improvement was observed in the control group (−0.01 ± 0.01, p < 0.001 for between-group comparison). RV/LV-ratio was reduced by 0.3 ± 0.2 in the CCIT-group and remained unchanged in the control group (−0.1 ± 0.1, p = 0.02 for between-group comparison). Safety outcomes, including in-hospital mortality and bleeding, were similar between the two treatment groups. Conclusion: In this pilot study, CCIT of intermediate-high risk PE was found to be effective and safe in comparison to conventional PE treatment. These findings warrant confirmation in larger-scale trials. © 2026 Wiley Periodicals LLC.