Percutaneous Mechanical Thrombectomy With or Without Low-Dose Catheter-Directed Thrombolysis in Acute Intermediate-High Risk Pulmonary Embolism (PMT-LDCDT-PE)

November 1, 2026 updated by: Qiu Jipeng

A Prospective Cohort Study Comparing Percutaneous Mechanical Thrombectomy Alone Versus Percutaneous Mechanical Thrombectomy Combined With Low-Dose Catheter-Directed Thrombolysis in the Treatment of Acute Intermediate-High Risk Pulmonary Embolism

Acute pulmonary embolism (PE) is the third most common cardiovascular cause of death. In patients with intermediate-high risk acute PE, percutaneous mechanical thrombectomy (PMT) using large-bore catheters achieves rapid hemodynamic improvement while avoiding the bleeding risk of systemic thrombolysis, and low-dose catheter-directed thrombolysis (CDT) can dissolve residual thrombus with a lower systemic bleeding risk. This prospective, multicenter, non-randomized cohort study aims to compare the safety and efficacy of PMT alone versus PMT combined with low-dose CDT (PMT+LDCDT) in patients with acute intermediate-high risk PE. Approximately 150 patients will be enrolled and allocated to either PMT alone or PMT+LDCDT based on operator assessment. The primary safety endpoint is the composite incidence of major adverse events (MAE) within 48 hours, and the primary efficacy endpoint is the change in the right ventricular/left ventricular (RV/LV) diameter ratio from baseline to 48 hours assessed by a CTPA core laboratory.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Acute PE is the third leading cause of cardiovascular death, and patients with intermediate-high risk PE-hemodynamically stable but with imaging-confirmed right ventricular dysfunction and elevated cardiac injury biomarkers-are at substantial risk of early deterioration. PMT with large-bore catheters enables immediate thrombus removal and hemodynamic recovery without systemic thrombolytic exposure, whereas CDT delivers low-dose thrombolytics locally to dissolve residual thrombus with a reduced systemic bleeding risk. Combining PMT with low-dose CDT (PMT+LDCDT) may improve thrombus clearance without a meaningful increase in bleeding. This prospective, multicenter cohort study will enroll approximately 150 patients with acute intermediate-high risk PE at centers with pulmonary vascular interventional capability. Patients will be allocated to PMT alone or PMT+LDCDT according to the operator's pre- and intra-procedural assessment. Participants will be followed at 24 h, 48 h, 7 days/discharge, 30 days, 90 days, 6 months and 12 months. The study will evaluate safety (48-hour MAE composite: all-cause death, intracranial hemorrhage, ISTH major bleeding and other major adverse events) and efficacy (change in RV/LV diameter ratio from baseline to 48 hours by CTPA core laboratory), as well as thrombus clearance, procedure time, length of stay, and the incidence of chronic thromboembolic pulmonary hypertension (CTEPH) at 6 and 12 months.

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age 18-80 years.
  • Acute pulmonary embolism confirmed by CTPA, with symptom onset to diagnosis ≤14 days.
  • Imaging evidence of right ventricular dysfunction (CTPA RV/LV diameter ratio ≥1.0, or echocardiographic right ventricular dilation/hypokinesia) and elevated cardiac injury biomarkers (troponin I or T above the upper limit of normal).
  • Presence of a contraindication to systemic thrombolysis, or failure of systemic thrombolysis, or clinical deterioration during anticoagulation.
  • Thrombus visible in the main pulmonary artery and/or lobar arteries on CTPA.
  • Provision of signed informed consent.

Exclusion Criteria:

  • Cardiac arrest at enrollment; systolic blood pressure <80 mmHg for >15 minutes unresponsive to fluid resuscitation and vasopressors.
  • Active bleeding; known coagulopathy (INR >2.0 or platelet count <50×10⁹/L); intracranial hemorrhage within 90 days, or intracranial tumor/vascular malformation; major surgery, major trauma, or stroke within 30 days.
  • Known heparin allergy or a history of heparin-induced thrombocytopenia.
  • Prior systemic thrombolytic therapy.
  • Known chronic thromboembolic pulmonary hypertension (CTEPH); severe left ventricular dysfunction (LVEF <30%); severe valvular heart disease; end-stage renal disease (eGFR <30 mL/min/1.73 m²); pregnancy or lactation.
  • Intracardiac or intrapulmonary mass on CTPA; severe stenosis or occlusion of the inferior vena cava or iliofemoral vein.
  • CTPA image quality inadequate for independent core laboratory interpretation.
  • Current participation in another clinical study that could interfere with endpoint assessment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: PMT alone (percutaneous mechanical thrombectomy only)

PMT alone (percutaneous mechanical thrombectomy only)
Device: PMT alone (percutaneous mechanical thrombectomy only)

Percutaneous mechanical thrombectomy system (e.g., FlowTriever, Indigo aspiration system)
Experimental: PMT plus low-dose catheter-directed thrombolysis (PMT+LDCDT)

PMT plus low-dose catheter-directed thrombolysis (PMT+LDCDT)
Device: PMT plus low-dose catheter-directed thrombolysis (PMT+LDCDT)

Low-dose catheter-directed thrombolysis: Alteplase (rt-PA), ≤20 mg (≤10 mg per lung), infused over ≤30 min via pulmonary artery catheter

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Composite incidence of major adverse events (MAE) within 48 hours after the procedure
Time Frame: within 48 hours post-procedure
within 48 hours post-procedure
Change in the RV/LV diameter ratio from baseline to 48 hours (ΔRV/LV) measured by CTPA core laboratory
Time Frame: baseline and 48 hours
baseline and 48 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Qiu Jipeng

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 10, 2026

Primary Completion (Estimated)

December 31, 2030

Study Completion (Estimated)

December 31, 2031

Study Registration Dates

First Submitted

October 4, 2026

First Submitted That Met QC Criteria

October 4, 2026

First Posted (Actual)

October 8, 2026

Study Record Updates

Last Update Posted (Actual)

November 3, 2026

Last Update Submitted That Met QC Criteria

November 1, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • WH6-PMT-LDCDT-2026-01

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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