Percutaneous Embolectomy, Low Dose Thrombolysis or Heparin for Intermediate High Risk Pulmonary Embolism (STRATIFY II)

NCT06453876 | Not Yet Recruiting Phase 3 DMC FDA Drug FDA Device

• 1 other identifier: STRATIFY-II 4.1 (10MAR2026)
• Study Type: interventional
• Target: 210
• Locations: 1 country
• Sites: 2

Brief Summary

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. Thus the two main hypothesis being tested are:

1. 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. 2.Thrombus burden reduction after 48-96 h is increased with percutaneous embolectomy compared to low-dose alteplase (2nd co-primary outcome)

Conditions

Pulmonary Embolism

Keywords

Randomized Clinical Trial; Pulmonary embolism; embolectomy; thrombolysis

Outcome Measures

Primary Outcomes (2)

• Thrombus burdon reduction (intervention vs. heparin)

  Reduction in modified Miller score (score of thrombus involvement and segmental flow) comparing percutaneous treated groups (embolectomy and low dose thrombolysis) to heparin/LMWH alone group, p\<0.01 (n=140 vs. n=70)

  To end of inclusion + 96 hours

• Thrombus burdon reduction (USAT vs. embolektomy)

  Reduction in modified Miller score (score of thrombus involvement and segmental flow) comparing percutaneous embolectomy and low dose thrombolysis, p\<0.04 (n=70 vs n=70)

  To end of inclusion + 96 hours

Secondary Outcomes (8)

• Bleeding complications (major and minor bleeding complication according the TIMI classification)

  3 months

• Duration of index admission, including hospital based rehabilitation

  3 months

• Dyspnea index (Visual analog scale) after 48-96 hours and after 3 months

  96 hours and 3 months

• Rate of further interventions for pulmonary embolism during index admission

  3 months

• Mortality in the three groups (log-rank), and hazard ratio in multivariable analysis using the UFH/LMWH as reference. Inclusion date of last patient's 3 month follow-up defines last day of follow-up

  1 year on avarage, at least 3 months

Study Arms (3)

Unfractionated Heparin / Low molecular heparin and thrombolysis if needed

ACTIVE COMPARATOR

Standard medical Therapy for intermediate-high risk pulmonary embolism

Drug: Heparin

Low dose thrombolysis

ACTIVE COMPARATOR

10 mg af alteplase intravenously over 6 hours total and heparin

Device: Ultrasound assisted Thrombolysis

Percutaneous Thrombectomy

ACTIVE COMPARATOR

Percutaneous Embolectomy using the AlphaVac, Angiodynamics or the Inari (R) Flowtriever thrombectomy system (R) and heparin

Device: Percutaneous Embolectomy

Interventions

Ultrasound assisted Thrombolysis DEVICE

Please see Arms

Also known as: EKOS system

Low dose thrombolysis

Percutaneous Embolectomy DEVICE

Please see arms

Also known as: Inari FlowTriever

Percutaneous Thrombectomy

Heparin DRUG

Active comparator

Also known as: Unfractionated or low molecular weight heparin

Unfractionated Heparin / Low molecular heparin and thrombolysis if needed

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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
• days of symptoms or less, with significant worsening of symptoms within 7 days

You may not qualify if:

• 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)
• Ongoing oral anticoagulation therapy (heparins, aspirin, antiplatelet therapy and NOAC allowed)
• Comorbidity making 6 months survival unlikely.
• 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

Sponsors & Collaborators

• Jesper Kjaergaard: lead
• Zealand University Hospital: collaborator
• Copenhagen University Hospital at Herlev: collaborator
• Odense University Hospital: collaborator
• Aalborg University Hospital: collaborator

Study Sites (2)

Copenhagen University Hospital Rigshospitalet

Copenhagen, DK2100, Denmark

Location

Odense University Hospital

Odense, 5000, Denmark

Location

MeSH Terms

Conditions

Pulmonary Embolism

Interventions

Heparin; Heparin, Low-Molecular-Weight

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases; Embolism; Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Glycosaminoglycans; Polysaccharides; Carbohydrates

Central Study Contacts

Jesper Kjaergaard, MD PhD DMSc

CONTACT

+4535450969; jesper.kjaergaard.05@regionh.dk

Lia Bang, MD PhD

CONTACT

+4535450988; lia.evi.bang@regionh.dk

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Consultant MD PhD DMSc

Model Details: 1:1:1 randomized allocation

Study Record Dates

• First Submitted: December 4, 2023
• First Posted: June 12, 2024
• Study Start: May 1, 2026
• Primary Completion (Estimated): June 5, 2028
• Study Completion (Estimated): October 31, 2029
• Last Updated: April 24, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

DK (2)