NCT07032025

Mechanical Thrombectomy for Acute Pulmonary Embolism

A Prospective, Multicenter, Randomized Controlled Trial of the Catheter-directed Mechanical Thrombectomy Compared to Standard Anticoagulation for Use in the Treatment of Acute Intermediate-risk Pulmonary Embolism.

• Status: Not Yet Recruiting
• Phase: EARLY_Phase 1
• Study type: Interventional
• Enrollment: 200 (estimated)
• Sponsor: RenJi Hospital · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

Research Objective: To prospectively compare the efficacy and safety of a pre-collaboratively developed ultra-thin PTFE minimally invasive thrombectomy system versus standard pharmacological therapy in patients with acute pulmonary embolism (PE), both administered on top of standard care. Research Content: Patients meeting all the following criteria will be enrolled: Aged 18-75 years (male or female) Clinically diagnosed with acute PE Right ventricular/left ventricular diameter ratio (RV/LV) ≥0.9 on computed tomographic pulmonary angiography (CTPA) Provision of voluntary written informed consent. Study Design: After confirming eligibility, subjects will be randomized at a 1:1 ratio into two groups: Innovative Device Group: Minimally invasive thrombectomy Standard Pharmacological Therapy Group: Pharmacological thrombolysis + anticoagulation Study Endpoints: Primary Efficacy Endpoint: Reduction in RV/LV ratio (measured by CTPA) from baseline to 48 hours post-treatment. Primary Safety Endpoint: Incidence of Major Adverse Events (MAEs) from baseline to 48 hours post-treatment, defined as: Procedure-related death Major bleeding (per VARC-2 criteria: life-threatening, disabling, or major bleeding) Treatment-related clinical deterioration, including: Unplanned mechanical ventilation Arterial hypotension (systolic blood pressure \<90 mmHg for \>1 hour or requiring vasopressors) or shock Cardiopulmonary resuscitation Sustained deterioration in oxygenation Emergency surgical embolectomy. Key Terminology Notes: RV/LV: Right Ventricular/Left Ventricular diameter ratio (standard medical abbreviation retained). VARC-2: Valve Academic Research Consortium-2 (internationally recognized bleeding criteria). PTFE: Polytetrafluoroethylene (material name preserved). MAE: Major Adverse Events (acronym defined at first use). Clinical deterioration: Explicitly specified with objective clinical indicators. This translation maintains scientific precision while adhering to international clinical trial reporting standards (ICH-GCP). The structure aligns with typical English-language study protocols for clarity and reproducibility.

Detailed description

1. Research Objective To prospectively evaluate the comparative efficacy and safety of a novel ultra-thin polytetrafluoroethylene (PTFE) minimally invasive thrombectomy system versus guideline-directed pharmacological thrombolysis in patients with acute intermediate-high-risk pulmonary embolism (PE), both administered as adjuncts to standard anticoagulation therapy. 2. Study Population Inclusion Criteria: Adults aged 18-75 years (all genders) Acute PE confirmed by computed tomographic pulmonary angiography (CTPA) within 14 days of symptom onset Right ventricular dysfunction defined as RV/LV diameter ratio ≥0.9 on baseline CTPA Provision of written informed consent Exclusion Criteria: Absolute contraindications to thrombolysis (e.g., active bleeding, recent intracranial hemorrhage, major surgery within 14 days) Hemodynamic instability requiring immediate rescue therapy (systolic BP \<90 mmHg with end-organ hypoperfusion) Severe renal impairment (eGFR \<30 mL/min/1.73m²) or hepatic failure (Child-Pugh Class C) Life expectancy \<6 months due to non-PE comorbidities 3. Study Design Design: Prospective, multicenter, open-label, randomized controlled trial with blinded endpoint adjudication Randomization: Eligible subjects stratified by PE severity (RV/LV: 0.9-1.0 vs. \>1.0) and thrombus burden (main/lobar vs. segmental PA involvement), then randomized 1:1 via centralized web-based system. Intervention Groups: Group A (Innovative Device): Ultra-thin PTFE thrombectomy catheter deployed under fluoroscopic guidance via femoral access Procedure completion within 90 minutes; mandatory peri-procedural unfractionated heparin (target ACT 250-300 s) Post-procedure: Enoxaparin 1 mg/kg BID → transitioned to rivaroxaban 20 mg OD at 24 hours Group B (Standard Therapy): Alteplase infusion: 10 mg bolus + 90 mg over 2 hours (max 100 mg) Concurrent heparin infusion (target aPTT 60-80 s) → switched to rivaroxaban 15 mg BID (Day 1-21) → 20 mg OD thereafter 4. Endpoint Definitions Primary Efficacy Endpoint Absolute reduction in RV/LV ratio from baseline to 48 hours post-intervention, measured by blinded core-lab CTPA analysis. Primary Safety Endpoint Composite Major Adverse Events (MAEs) within 48 hours, including: Procedure-related mortality Major bleeding per VARC-2 criteria: Fatal bleeding Intracranial hemorrhage Bleeding causing ≥3 g/dL hemoglobin drop or transfusion of ≥2 units Bleeding requiring surgical intervention Treatment-related clinical deterioration: Unplanned mechanical ventilation Sustained hypotension (SBP \<90 mmHg for \>1 hour requiring vasopressors) Cardiopulmonary resuscitation New requirement for ECMO or emergency surgical embolectomy 5. Statistical Analysis Plan Sample Size: 142 subjects/group (total N=284) providing 90% power (α=0.05) to detect: Efficacy: Mean RV/LR reduction difference of 0.15 (SD=0.3) Safety: 40% relative risk reduction in MAEs (Group A: 10% vs. Group B: 17%) Analysis Sets: Primary analysis: Modified intention-to-treat (mITT; all randomized receiving ≥1 treatment component) Safety analysis: As-treated population Methods: Continuous variables: Mixed-effects repeated measures ANOVA Categorical variables: Cochran-Mantel-Haenszel test with stratification adjustment Time-to-event: Kaplan-Meier with log-rank test 6. Quality Assurance Endpoint Adjudication Committee: Blinded to treatment allocation Data Monitoring: Independent DSMB reviewing unblinded safety data quarterly Procedure Standardization: All interventionalists certified via simulation training (≥5 proctored cases) Centralized core lab for CTPA RV/LV measurements Ethical Compliance: Approved by institutional review boards at all sites (NCT# pending). Trial conducted per Declaration of Helsinki. Key Advantages of Expanded Protocol Stratified randomization controls confounding from baseline RV strain heterogeneity. VARC-2 bleeding criteria enhance comparability with cardiovascular intervention trials. Core-lab blinded CTPA analysis eliminates measurement bias in efficacy assessment. Pre-specified safety triggers (e.g., Hb drop thresholds) enable objective MAE classification. Standardized anticoagulation bridging minimizes post-procedural thrombotic risk variability.

Conditions

• Acute Pulmonary Embolism

Interventions

Type	Name	Description
PROCEDURE	Innovative Device Group	Catheter-based thrombectomy is performed within 4 hours after baseline CTPA acquisition. Pre-procedural anticoagulation with either low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) is administered prior to thrombectomy. Post-procedural oral anticoagulation is transitioned to rivaroxaban 20 mg once daily (QD).
DRUG	Standard Pharmacological Therapy Group	Following thrombolytic agent administration, anticoagulation with rivaroxaban is initiated and maintained at 15 mg twice daily (BID) for the initial 3 weeks, then switched to 20 mg once daily (QD) thereafter.

Timeline

• Start date: 2025-07-01
• Primary completion: 2027-07-01
• Completion: 2027-07-01
• First posted: 2025-06-22
• Last updated: 2025-06-22