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

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 10, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 4, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 8, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 1, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings