Low Dose Thrombolysis, Ultrasound Assisted Thrombolysis or Heparin for Intermediate High Risk Pulmonary Embolism (STRATIFY)
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ClinicalTrials.gov Identifier: NCT04088292 |
Recruitment Status :
Recruiting
First Posted : September 12, 2019
Last Update Posted : November 18, 2023
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Condition or disease | Intervention/treatment | Phase |
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Pulmonary Embolism | Drug: Alteplase 20 Mg Powder for Solution for Injection Vial Device: Ultrasound assisted Thrombolysis | Phase 3 |
Trial acronym: STRATIFY Background: Intermediate-high risk pulmonary embolism (PE) is associated with a significant risk of death or hemodynamic deterioration. The optimal treatment strategy should balance efficacy in reducing thrombus burden and hemodynamic compromise with risk of complications, in particular bleeding. Previous studies have investigated conventional high-dose, short term thrombolysis by (rtPA), finding a reduction in risk hemodynamic deterioration, but no reduction in mortality and a substantial increase in significant bleeding complications.
Catheter based techniques and low dose thrombolysis may offer lower risk of complication with reasonable efficacy. Such studies have not been performed in RCTs with a reasonable sample size, and no study have compared low dose intravenous thrombolysis and catheter based techniques.
The current trial addresses this paucity of data by randomizing patients to one of three treatment modalities:
Intervention: 1:1:1 randomization, stratified for site to
- UltraSound Assisted Thrombolysis (USAT) with low dose thrombolysis (20 mg of rtPA, Alteplase) over 6 hours plus unfractionated heparin (UFH) or low molecular weight heparin (LMWH) within 12 hours of randomization
- Intravenous low dose thrombolysis (20 mg of rtPA, Alteplase) over 6 hours plus UFH or low molecular weight heparin (LMWH).
- UFH or low molecular weight heparin (LMWH) only (with option for conventional thrombolysis according to local protocols for hemodynamic deterioration) Design: Regional collaborative, randomized trial with 1:1:1 allocation of 210 patients with acute intermediate-high risk PE with no absolute contraindications to thrombolysis
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 210 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Randomized clinical trial with 1:1:1 allocation to treatment strata |
Masking: | Single (Outcomes Assessor) |
Masking Description: | Primary endpoint will be assessed by assessor blinded to the intervention |
Primary Purpose: | Treatment |
Official Title: | Low Dose Thrombolysis, Ultrasound Assisted Thrombolysis or Heparin for Intermediate High Risk Pulmonary Embolism |
Actual Study Start Date : | June 6, 2019 |
Estimated Primary Completion Date : | June 5, 2024 |
Estimated Study Completion Date : | October 31, 2024 |

Arm | Intervention/treatment |
---|---|
Active Comparator: USAT + low dose thrombolysis
UltraSound Assisted Thrombolysis (USAT) with low dose thrombolysis (20 mg of rtPA, Alteplase) over 6 hours plus unfractionated heparin (UFH) or low molecular weight heparin (LMWH) within 12 hours of randomization
|
Drug: Alteplase 20 Mg Powder for Solution for Injection Vial
Low dose alteplase delivered IV or bu Ultrasound Assisted Thrombolysis device Device: Ultrasound assisted Thrombolysis Ultrasound assisted thrombolysis (USAT) |
Active Comparator: Low dose thrombolysis
Intravenous low dose thrombolysis (20 mg of rtPA, Alteplase) over 6 hours plus UFH or low molecular weight heparin (LMWH).
|
Drug: Alteplase 20 Mg Powder for Solution for Injection Vial
Low dose alteplase delivered IV or bu Ultrasound Assisted Thrombolysis device |
No Intervention: Heparin alone
UFH or low molecular weight heparin (LMWH) only (with option for conventional thrombolysis according to local protocols for hemodynamic deterioration)
|
- Reduction in Miller score comparing low dose thrombolysis and heparin alone groups [ Time Frame: at 48 to 96 hours post randomization ]Reduction in Miller Score and on follow-up (48-96 h) CT pulmonary Angiography comparing low-dose rtPA (±USAT) to UFH/LMWH group (p<0.01, N=210)
- Reduction i Miller score comparing low dose thrombolysis by iv and by USATgroups [ Time Frame: at 48 to 96 hours post randomization ]reduction in Miller Score and on follow-up (48-96 h) CT pulmonary Angiography comparing low-dose rtPA by USAT to iv, p<0.04, N=140)
- Incidence of bleeding complications [ Time Frame: Until hospital discharge, on average 1 week ]Bleeding complications (major and minor bleeding complication according the TIMI classification)
- Length of stay of index admission [ Time Frame: End of study, expected to be 2 years ]Duration of index admission, including hospital based rehabilitation
- Dyspnea index by visual analogue scale [ Time Frame: End of study, expected to be 2 years ]Dyspnea index (Visual analog scale) after 48-96 h and after 3 months
- Change in oxygen supplement (FiO2) [ Time Frame: at 48 to 96 hours post randomization ]FiO2 (in %)
- Mortality rate [ Time Frame: End of study, expected to be 2 years ]Mortality in the three groups (log-rank), and hazard ratio in multivariable analysis using the UFH/LMWH as reference
- Reduction in D-dimer values [ Time Frame: at 48 to 96 hours post randomization ]Reduction in D-dimer from baseline to 48-96h post randomization
- Incidence of Pulmonary Hypertension [ Time Frame: 3 months follow-up ]Incidence of TR gradient > 40 mmHg at 3 months follow-up echocardiography
- Reduction in troponin levels [ Time Frame: at 48 to 96 hours post randomization ]Relative reduction in TnI/T from baseline to 48-96 h post intervention
- Reduction in NT-pro-BNP levels [ Time Frame: 3 months follow-up ]Reduction in NT-pro-BNP at 48-96 hours and 3 months

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Age ≥ 18 years
- Informed consent for trial participation
- Intermediate high-risk PE according to ESC criteria
- Thrombus visible in main, lobar or segmental pulmonary arteries on CT angiography
- 14 days of symptoms or less
Exclusion Criteria:
- Altered mental state (GCS < 14)
- No qualifying CT angiography performed (> 24 hour since CT angiography)
- Females of child bearing 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
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Absolute contraindications for thrombolysis
- Hemorrhagic stroke or stroke of unknown origin at any time
- Ischemic stroke in the preceding 6 months
- Central nervous system damage or neoplasms
- Recent major trauma/surgery/head injury in the preceding 3 weeks
- Gastrointestinal bleeding within the last month
- Known bleeding risk

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04088292
Contact: Jesper Kjærgaard, MD PhD DMSc | +45 35450969 | jesper.kjaergaard.05@regionh.dk | |
Contact: Lia Bang, MD PhD | +45 35453545 | lia.evi.bang@regionh.dk |
Denmark | |
Copenhagen University Hospital Bispebjerg Hospital | Not yet recruiting |
Bispebjerg, Denmark, DK2400 | |
Contact: Michael Egstrup, MD PhD +45 38 63 50 00 | |
Copenhagen University Hospital Rigshospitalet | Recruiting |
Copenhagen, Denmark, DK2100 | |
Contact: Lia E Bang, MD PhD +45 3545 3545 lia.evi.bang@regionh.dk | |
Copenhagen University Hospital, Herlev Gentofte Hospital | Not yet recruiting |
Herlev, Denmark, DK2730 | |
Contact: Søren Fanø, MD PhD +45 38 68 38 68 |
Responsible Party: | Jesper Kjaergaard, Sponsor, Primary investigator, Rigshospitalet, Denmark |
ClinicalTrials.gov Identifier: | NCT04088292 |
Other Study ID Numbers: |
STRATIFY-1 |
First Posted: | September 12, 2019 Key Record Dates |
Last Update Posted: | November 18, 2023 |
Last Verified: | November 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Undecided |
Plan Description: | Main trial database |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | Yes |
Product Manufactured in and Exported from the U.S.: | Yes |
Pulmonary Embolism Embolism Embolism and Thrombosis Vascular Diseases Cardiovascular Diseases Lung Diseases |
Respiratory Tract Diseases Tissue Plasminogen Activator Fibrinolytic Agents Fibrin Modulating Agents Molecular Mechanisms of Pharmacological Action |