March 1, 2026Open Access

Efficacy and Safety of Low-Dose Prolonged Infusion Thrombolysis With rt-PA for Acute Intermediate-High Risk Pulmonary Embolism.

Q: What question did this study set out to answer?

This research aims to determine the efficacy and safety of low-dose prolonged infusion thrombolysis for acute intermediate-high risk pulmonary embolism.

Key Result

Low-dose prolonged infusion rt-PA increased thrombus clearance (64.85% vs. 41.65%, p<0.001) and reduced pulmonary hypertension incidence (27.87% vs. 54.55%, p=0.004) in intermediate-high risk PE.

Key Points

This research aims to determine the efficacy and safety of low-dose prolonged infusion thrombolysis for acute intermediate-high risk pulmonary embolism.
Evaluated 120 patients divided into anticoagulant and thrombolytic groups.
Measured pulmonary artery thrombus clearance rates and treatment-related bleeding incidents.
Assessed 30-day mortality and 3-6 month pulmonary hypertension incidence.
Thrombolytic group had a higher thrombus clearance rate (64.85% vs. 41.65%, p < 0.001).
No significant difference in 30-day mortality between groups (1.61% vs. 5.17%, p = 0.278).
Higher D-dimer and FDP levels post-treatment in the thrombolytic group, correlating with thrombus clearance (all p < 0.001).
Significantly lower pulmonary artery systolic pressure and incidence of pulmonary hypertension in the thrombolytic group (p < 0.05).

Structured PICO

Does low-dose prolonged infusion thrombolysis improve thrombus clearance and reduce pulmonary hypertension in patients with acute intermediate-high risk pulmonary embolism compared to anticoagulation alone?

Population

120 patients with acute intermediate-high risk pulmonary embolism

Intervention

Low-dose prolonged infusion thrombolysis with rt-PA

Comparator

Anticoagulant therapy

Outcome

Pulmonary artery thrombus clearance rate, 30-day all-cause mortality, 3-6 month pulmonary hypertension incidence, and treatment-related bleedingsurrogate

Low-dose prolonged infusion thrombolysis effectively clears pulmonary artery thrombi and reduces the incidence of pulmonary hypertension in acute intermediate-high-risk PE without significantly increasing major bleeding.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Thrombolytic therapy alleviates pulmonary embolism (PE) symptoms rapidly but increases bleeding risk, with no consistent consensus on acute intermediate-high risk PE. This study evaluated the efficacy and safety of low-dose prolonged infusion thrombolysis for acute intermediate-high risk PE to provide a safer clinical option. A total of 120 patients were collected and divided into anticoagulant (Group A, n = 58) and thrombolytic (Group B, n = 62) groups. Efficacy outcomes included pulmonary artery thrombus clearance rate, 30-day all-cause mortality, and 3-6 month pulmonary hypertension incidence; the primary safety outcome was treatment-related bleeding. Both groups showed improved SBP, DBP, SpO₂, and RV/LV ratio (all p p p = 0.278). At 1 day, post-treatment, Group B had higher D-dimer (26.78 ± 16.57 μg/mL vs. 7.60 ± 7.23 μg/mL) and FDP (91.45 ± 97.37 μg/mL vs. 18.60 ± 26.34 μg/mL, all p p = 0.091); these differences persisted until discharge (all p p = 0.073), the difference between the two groups was not statistically significant. No fatal bleeding, intracranial hemorrhage, or recurrent pulmonary embolism occurred in either group. Group B had lower 3-6 month pulmonary artery systolic pressure (PASP) (30.70 ± 9.70 vs. 34.44 ± 10.04 mmHg, p = 0.045) and pulmonary hypertension incidence (27.87% vs. 54.55%, p = 0.004). Thrombus clearance rate correlated with treatment group (r = 0.57, p r = 0.42) and FDP (r = 0.32) levels at 1 day post-treatment (both p < 0.001). Low-dose prolonged infusion can effectively clear pulmonary artery thrombi in patients with acute intermediate-high-risk PE, which may be associated with a reduced incidence of pulmonary hypertension. Patients in the thrombolysis group showed significant dynamic changes in D-dimer and FDP levels, which were significantly correlated with a higher thrombus clearance rate.