Comparing clot removal, low-dose clot-dissolving drug, and heparin for pulmonary embolism
Compares clot removal, low-dose alteplase and heparin in pulmonary embolism.
Key facts
- Who runs it
- Jesper Kjaergaard
- Where
- Denmark2 sites in 1 countryChoose a country to see its sites
- Trial code
- Registry title
- Percutaneous Embolectomy, Low Dose Thrombolysis or Heparin for Intermediate High Risk Pulmonary Embolism (STRATIFY II)
- Status
- Recruiting
- Phase
- Phase 3
- People taking part
- 210 people, planned
- Started
- 17 Jun 2026
- Expected to end
- 31 Oct 2029
- Type of study
- Interventional, 3 groupsOne group gets an existing treatment, for comparison.
- Treatments tested
- Ultrasound assisted Thrombolysis
- Percutaneous Embolectomy
- Heparin
- Record updated
- 2 July 2026
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with a recent, intermediate high-risk blood clot in the lungs (pulmonary embolism). It compares clot removal through a catheter, low-dose clot-dissolving drug, and heparin.
- Age
- 18 years or older
- Sex
- All sexes
- Disease stage
- Acute intermediate high-risk pulmonary embolism by ESC criteria. Class II risk on the Pulmonary Embolism Severity Index. Clot seen in main, lobar or segmental lung arteries on CT angiography. Symptoms for 14 days or less, with clear worsening within 7 days.
- Earlier treatment
- No clot-dissolving treatment (thrombolysis) for the lung clot within 14 days. No ongoing oral blood thinners; heparins, aspirin, antiplatelet drugs and NOAC are allowed.
Main reasons for not taking part
- Reduced alertness (GCS < 14)
- No CT angiography within the last 24 hours
- Clot passing through a hole between the heart chambers (patent Foramen Ovale)
- Other illness making survival for 6 months unlikely
- Reasons clot-dissolving drugs cannot be given: past bleeding stroke, stroke in the last 6 months, brain tumour, major injury or surgery in the last 3 weeks, active bleeding
The registry criteria, word for word
Show all 13 criteriaShow less
Who can take part
- Age ≥ 18 years
- Intermediate high-risk PE according to ESC criteria
- Class II risk assessed by the Pulmonary Embolism Severity Index (1)
- Thrombus visible in main, lobar or segmental pulmonary arteries on CT angiography
- 14 days of symptoms or less, with significant worsening of symptoms within 7 days
Who cannot take part
- Ongoing oral anticoagulation therapy (heparins, aspirin, antiplatelet therapy and NOAC allowed)
- Absolute contraindications for thrombolysis:; History of haemorrhagic stroke or stroke of unknown origin; Ischaemic stroke in previous 6 months; Central nervous system neoplasm; Major trauma, surgery, or head injury in previous 3 weeks; Bleeding diathesis - Active bleeding
- Altered mental state (GCS < 14)
- No qualifying CT angiography performed (> 24 hour since CT angiography)
- Women of childbearing potential, unless negative HCG test is present
- Thrombolysis for PE within 14 days of randomization
- Thrombus passing through patent Foramen Ovale (risk of paradoxical embolism)
- Comorbidity making 6 months survival unlikely
This trial has no sites in United States.
It has sites in one country. Choose a country to see its sites.
About the trial
What the trial wants to find out
The STRATIFY II trial investigates the efficacy of three different approaches to reducing thrombus burdon in patients with acute intermediate high-risk pulmonary embolism: percutaneous embolectomy (the AlphaVAC(R), AngioDynamics or the Flow Triever® system, INARI medical), Low intravenous thrombolysis (Alteplase 10 mg) and heparin with the option to perform full-dose thrombolysis. As a co-primary secondary end point the trial assess the incremental efficacy of the embolectomy vs the catheter based low dose thrombolysis approach.
Read full original descriptionShow less
Thus the two main hypothesis being tested are:
1. Thrombus burden reduction after 48-96 h is increased with a catheter based (embolectomy or low-dose alteplase) compared to the a heparin with optional high dose thrombolysis approach (1st co-primary outcome) 2. Thrombus burden reduction after 48-96 h is increased with percutaneous embolectomy compared to low-dose alteplase (2nd co-primary outcome)
The 3 groups in the trial
- Unfractionated Heparin / Low molecular heparin and thrombolysis if neededExisting treatment, for comparison
Standard medical Therapy for intermediate-high risk pulmonary embolism
Treatment: Heparin
- Low dose thrombolysisExisting treatment, for comparison
10 mg af alteplase intravenously over 6 hours total and heparin
Treatment: Ultrasound assisted Thrombolysis
- Percutaneous ThrombectomyExisting treatment, for comparison
Percutaneous Embolectomy using the AlphaVac, Angiodynamics or the Inari (R) Flowtriever thrombectomy system (R) and heparin
Treatment: Percutaneous Embolectomy
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Percutaneous Embolectomy, Low Dose Thrombolysis or Heparin for Intermediate High Risk Pulmonary Embolism (STRATIFY II)
- Plain-language title
- Comparing clot removal, low-dose clot-dissolving drug, and heparin for pulmonary embolismGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 15 November 2026.
- Record updated
- 2 July 2026