# A comparative study of anticoagulation combined with different catheter-directed thrombolysis strategies (urokinase catheter-directed vs. alteplase infusion) in the treatment of intermediate-risk pulmonary embolism

## TL;DR

This study compares two thrombolysis methods for treating intermediate-risk pulmonary embolism and finds both are similarly effective and safe.

## Contribution

The study provides a direct comparison of urokinase and alteplase in catheter-directed thrombolysis for pulmonary embolism.

## Key findings

- Both urokinase and alteplase improved key clinical indicators after treatment.
- No significant differences in efficacy or safety were found between the two groups.
- Alteplase may offer practical advantages due to shorter catheter placement.

## Abstract

To compare the clinical efficacy and safety of anticoagulation combined with catheter-directed urokinase (UK) thrombolysis vs. anticoagulation combined with catheter-directed alteplase (rt-PA) infusion thrombolysis in patients with intermediate-risk acute pulmonary embolism (APE).

A retrospective analysis was conducted on intermediate-risk APE patients treated at our center between June 2022 and May 2025, all of whom received anticoagulation combined with catheter-directed thrombolysis. The UK group (n = 56) received continuous UK infusion via pulmonary artery catheter (400,000–500,000 IU/day for 2–3 days), while the rt-PA group (n = 23) received intraprocedural rt-PA infusion (20 mg/30 min). Changes in cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), right ventricular diameter/left ventricular diameter (RVD/LVD), and pulmonary artery obstruction index (PAOI) were compared before and after treatment.

Baseline characteristics showed no significant differences between groups (P > 0.05). Post-treatment, the UK group demonstrated significant improvements in PAOI, RVD/LVD, NT-proBNP, and cTnI (P < 0.05), while the rt-PA group showed significant improvements in PAOI, RVD/LVD, and cTnI (P < 0.05) but not NT-proBNP (P = 0.088). There were no statistically significant differences in the aforementioned indicators between the two groups at both pre-treatment and post-treatment time points (P > 0.05). There were no statistically significant differences in in-hospital mortality, the incidence of bleeding adverse events, and hospital stay duration between the two groups (P > 0.05).

For intermediate-risk APE, catheter-directed UK thrombolysis and intraprocedural rt-PA infusion offer comparable efficacy and safety. However, the rt-PA regimen may be more advantageous due to its avoidance of prolonged catheter placement.