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Reduced-Dose Versus Full-Dose Alteplase for High-Risk Pulmonary Embolism (REDSTEM)

14 septembre 2026 mis à jour par: Kristina Svennerholm, Sahlgrenska University Hospital

Reduced-Dose Versus Full-Dose Systemic Thrombolysis for High-Risk Pulmonary Embolism: A Multicentre, Randomised, Open-Label, Blinded-Endpoint Trial

High-risk pulmonary embolism is a life-threatening condition requiring immediate reperfusion therapy. Full-dose systemic thrombolysis is recommended as first-line treatment, but its use is limited by the risk of major bleeding, including intracranial hemorrhage. Reduced-dose systemic thrombolysis may reduce bleeding while maintaining clinical efficacy, but this strategy has not been adequately evaluated in patients with high-risk pulmonary embolism.

REDSTEM is an international, multicenter, randomized, adaptive, open-label, blinded-endpoint phase 4 trial comparing reduced-dose alteplase with standard full-dose alteplase in adults with acute high-risk pulmonary embolism. The trial will assess whether reduced-dose alteplase preserves early clinical efficacy while reducing severe clinically significant bleeding. Participants will be followed for up to 12 months.

Aperçu de l'étude

Statut

Pas encore de recrutement

Les conditions

Description détaillée

Systemic thrombolysis is recommended as first-line reperfusion therapy for high-risk pulmonary embolism. However, bleeding complications limit its use in clinical practice and contribute to undertreatment of eligible patients. Existing evidence from small randomized trials, observational studies, and meta-analyses suggests that lower-dose thrombolysis may improve safety while maintaining efficacy, but previous studies have included mixed-risk pulmonary embolism populations and only a limited number of patients with high-risk pulmonary embolism.

REDSTEM was designed to evaluate whether a reduced-dose alteplase strategy can provide a more favorable balance between efficacy and safety compared with standard full-dose alteplase in patients with high-risk pulmonary embolism. The study uses randomized treatment allocation, blinded endpoint adjudication, independent safety monitoring, and an adaptive design allowing sample-size re-estimation if required.

The trial includes early clinical assessments during the acute phase and follow-up through 12 months to evaluate clinical outcomes, safety, functional recovery, quality of life, and health care resource utilization.

Type d'étude

Interventionnel

Inscription (Estimé)

400

Phase

  • Phase 4

Contacts et emplacements

Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.

Coordonnées de l'étude

Sauvegarde des contacts de l'étude

Lieux d'étude

      • Copenhagen, Danemark
        • Rigshospitalet
        • Contact:
          • Jesper Kjaergaard, MD, PhD
      • Bergen, Norvège, 5021
        • Haukeland University Hospital
        • Contact:
          • Lasse Melvear Gii, MD, PhD
      • Drammen, Norvège, 3004
        • Drammen Hospital
        • Contact:
          • Jonas Pivoriunas, MD, PhD
      • Grålum, Norvège, 1714
        • Ostfold Hisptal
        • Contact:
          • Hans Joakim Myklebust-Hansen, MD
      • Lörenskog, Norvège, 1478
        • Akershus University Hospital
        • Contact:
          • Hamza Nahoui, MD
      • Oslo, Norvège, 0450
        • Oslo University Hospital, Ullevål
        • Contact:
          • Mari Asphjell Björnaas, MD, PhD
      • Stavanger, Norvège, 4021
        • Stavanger University Hospital
        • Contact:
          • Trond Johan Cooper, MD
      • Falun, Suède
        • Falun Hospital
        • Contact:
          • Jessica Silfverberg, MD
      • Gothenburg, Suède
        • Sahlgrenska University Hospital/Östra
        • Contact:
          • Katarina Glise Sandblad, MD, PhD
      • Jönköping, Suède
        • Ryhov County Hospital
        • Contact:
          • Antheia Kissopoulou, MD, PhD
      • Lund, Suède
        • Skåne University Hospital, Lund
        • Contact:
          • Marcus Ohlsson, MD
      • Malmö, Suède
        • Skåne University Hospital, Malmö
        • Contact:
          • Marcus Ohlsson, MD, PhD
      • Mölndal, Suède
        • Sahlgrenska University Hospital/Mölndal
        • Contact:
          • Louise Martinell, MD, PhD
      • Norrtälje, Suède
        • Norrtälje Hospital
        • Contact:
          • Sune Forsberg, MD, PhD
      • Skövde, Suède
        • Skaraborgs Hospital Skövde
        • Contact:
          • Freyr Einarsson, MD
        • Contact:
          • Erik Ullemark, MD
      • Stockholm, Suède
        • Danderyd Hospital
        • Contact:
          • Nina Olausson, MD, PhD
      • Stockholm, Suède
        • Karolinska University Hospital, Solna
        • Contact:
          • Therese Djärv, MD, PhD
      • Stockholm, Suède
        • Karolinska University Hospital, Huddinge
        • Contact:
          • Therese Djärv, MD, PhD
      • Stockholm, Suède
        • Capio S:t Göran's Hospital
        • Contact:
          • Rickard Markgren, MD, PhD
      • Stockholm, Suède
        • Södersjukhuset, Stockholm South General Hospital
        • Contact:
          • Jacob Hollenberg, MD, PhD
      • Umeå, Suède
        • University Hospital of Umeå
        • Contact:
          • Johanna Pennlert, MD, PhD
      • Uppsala, Suède
        • Uppsala University Hospital
        • Contact:
          • Sofia Vikman, MD, PhD
    • Västra Götaland County

Critères de participation

Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.

Critère d'éligibilité

Âges éligibles pour étudier

  • Adulte
  • Adulte plus âgé

Accepte les volontaires sains

Non

La description

Inclusion Criteria:

  1. Participant aged 18 years or older.
  2. Acute pulmonary embolism verified by computed tomography pulmonary angiography or pulmonary angiography. In hemodynamically unstable participants unable to undergo immediate imaging, presumed pulmonary embolism may be diagnosed based on bedside echocardiographic findings consistent with acute right ventricular pressure overload and high clinical suspicion of pulmonary embolism, provided that alternative causes of hemodynamic instability have been reasonably excluded. In such cases, the treating clinician must have independently decided to initiate thrombolytic therapy irrespective of study participation, and confirmatory imaging demonstrating pulmonary embolism must be performed as soon as clinically feasible.
  3. High risk for early death, defined by at least one of the following:

    1. High-risk pulmonary embolism according to European Society of Cardiology criteria:

      • Cardiac arrest with return of spontaneous circulation;
      • Obstructive shock, defined as systolic blood pressure <90 mmHg or use of vasopressors to maintain systolic blood pressure ≥90 mmHg despite adequate filling status, together with end-organ hypoperfusion such as elevated serum lactate >2 mmol/L, altered mental status, or cold clammy skin;
      • Persistent hypotension, defined as systolic blood pressure <90 mmHg or a drop in systolic blood pressure ≥40 mmHg for longer than 15 minutes, not caused by new-onset arrhythmia, hypovolemia, or sepsis.
    2. Abnormal right ventricular function on echocardiography or computed tomography pulmonary angiography, defined as right ventricular/left ventricular ratio ≥1.0, and elevated cardiac troponin above the local upper reference limit, and acute respiratory failure not primarily caused by underlying lung disease, defined as requiring facemask oxygen supplementation ≥12 L/min, high-flow nasal oxygen, or non-invasive ventilation with FiO2 ≥60% to reach oxygen saturation ≥94%.
  4. Female participants of childbearing potential must have a negative urine or serum pregnancy test.

Exclusion Criteria:

  1. Catastrophic pulmonary embolism, defined as ongoing cardiac arrest and/or need for extracorporeal cardiopulmonary resuscitation and/or immediate VA-ECMO as judged by the treating physicians.
  2. Known hypersensitivity to alteplase or any of its excipients.
  3. Contraindication to systemic thrombolysis with one or more of the following:

    • History of hemorrhagic stroke;
    • Ischemic stroke within the previous 6 months;
    • Central nervous system neoplasm;
    • Major trauma, major surgery, or major head injury within the previous 3 weeks;
    • Active life-threatening bleeding, bleeding into a critical organ or area, or known severe bleeding diathesis;
    • Chronic use of full-dose oral or parenteral anticoagulation before presentation.
  4. The participant has already received reperfusion treatment for the index pulmonary embolism before randomization, including systemic thrombolysis, surgical embolectomy, or catheter-directed intervention.
  5. Pregnancy.
  6. Current participation in another study that would interfere with participation in this trial.
  7. Any other condition that would put the participant at unacceptable risk from the trial interventions as judged by the treating clinician.
  8. In countries where required by national regulations: lack of affiliation to a social security system or equivalent health insurance coverage.

Plan d'étude

Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.

Comment l'étude est-elle conçue ?

Détails de conception

  • Objectif principal: Traitement
  • Répartition: Randomisé
  • Modèle interventionnel: Affectation parallèle
  • Masquage: Seul

Armes et Interventions

Groupe de participants / Bras
Intervention / Traitement
Expérimental: Reduced-Dose Alteplase
Participants randomized to reduced-dose systemic thrombolysis will receive alteplase 0.6 mg/kg body weight, up to a maximum dose of 50 mg, administered intravenously over 15 minutes.
Alteplase 0.6 mg/kg body weight, maximum 50 mg, administered as an intravenous infusion over 15 minutes
Autres noms:
  • Reduced-dose systemic thrombolysis, Low-dose alteplase, tPA
Comparateur actif: Full-Dose Alteplase
Participants randomized to standard full-dose systemic thrombolysis will receive alteplase 1.5 mg/kg body weight, up to a maximum dose of 100 mg, administered as a 10 mg intravenous bolus over 1 to 2 minutes followed by a 90 mg intravenous infusion over 2 hours.
Alteplase 1.5 mg/kg body weight, maximum 100 mg, administered as a 10 mg intravenous bolus over 1 to 2 minutes followed by 90 mg as an intravenous infusion over 2 hours.
Autres noms:
  • Full-dose systemic thrombolysis, Standard-dose alteplase, tPA

Que mesure l'étude ?

Principaux critères de jugement

Mesure des résultats
Description de la mesure
Délai
Incidence of composite efficacy endpoint
Délai: Within 7 days after randomization
Incidence of a composite endpoint comprising all-cause mortality within 7 days, cardiopulmonary resuscitation and/or veno-arterial extracorporeal membrane oxygenation within 7 days, recurrent pulmonary embolism within 7 days, clinical deterioration within 24 hours, and lack of clinical improvement at 6 hours.
Within 7 days after randomization
Key secondary endpoint - Incidence of severe clinically significant bleeding
Délai: Within 7 days after randomization
Incidence of severe clinically significant bleeding, defined as major bleeding according to International Society on Thrombosis and Haemostasis criteria or bleeding requiring urgent medical intervention.
Within 7 days after randomization

Mesures de résultats secondaires

Mesure des résultats
Description de la mesure
Délai
All-cause mortality
Délai: At 7 days and 30 days after randomization
Incidence of death from any cause.
At 7 days and 30 days after randomization
Pulmonary embolism-related mortality
Délai: At 7 days and 30 days after randomization
Incidence of pulmonary embolism-related death.
At 7 days and 30 days after randomization
Cardiopulmonary resuscitation and/or VA-ECMO
Délai: Within 7 days after randomization
Incidence of cardiopulmonary resuscitation and/or veno-arterial extracorporeal membrane oxygenation.
Within 7 days after randomization
Incidence of clinical deterioration
Délai: Within 24 hours after randomization
Incidence of life-threatening hemodynamic or respiratory decline requiring cardiopulmonary resuscitation, endotracheal intubation, or VA-ECMO, or an increase in SCAI SHOCK stage after investigational medicinal product administration.
Within 24 hours after randomization
Lack of clinical improvement assessed by SCAI SHOCK stage and oxygen requirement
Délai: At 6 hours after randomization
Incidence of unchanged SCAI SHOCK stage or unchanged or rising fraction of inspired oxygen required to maintain oxygen saturation of at least 94%.
At 6 hours after randomization
Time to clinical stabilization based on predefined hemodynamic and respiratory criteria
Délai: From randomization until clinical stabilization, assessed up to 7 days after randomization
Time from randomization to the time point at which predefined hemodynamic or respiratory stabilization criteria have been continuously fulfilled for at least 30 minutes
From randomization until clinical stabilization, assessed up to 7 days after randomization
Incidence of recurrent pulmonary embolism
Délai: At 7 days and 30 days after randomization
Incidence of objectively confirmed recurrent pulmonary embolism.
At 7 days and 30 days after randomization
Initiation of invasive or non-invasive mechanical ventilation
Délai: Within 7 days after randomization
Incidence of initiation of invasive or non-invasive mechanical ventilation.
Within 7 days after randomization
Win ratio for efficacy
Délai: Within 7 days after randomization
Win ratio based on all-cause mortality, cardiopulmonary resuscitation and/or VA-ECMO, clinical deterioration, lack of clinical improvement, recurrent pulmonary embolism, and time to clinical stabilization.
Within 7 days after randomization
Net clinical benefit
Délai: Within 7 days after randomization
Composite net clinical benefit including severe clinically significant bleeding, all-cause mortality, cardiopulmonary resuscitation and/or VA-ECMO, recurrent pulmonary embolism, clinical deterioration, and lack of clinical improvement.
Within 7 days after randomization
Rescue treatment
Délai: Before clinical stabilization, up to 7 days after randomization
Need for rescue treatment, defined as additional alteplase, catheter-directed intervention, surgical embolectomy, or VA-ECMO before stabilization.
Before clinical stabilization, up to 7 days after randomization
ICU or high-dependency unit length of stay in days
Délai: Within 30 days after randomization
Length of stay in intensive care unit and/or high-dependency unit.
Within 30 days after randomization
Hospital length of stay
Délai: Within 30 days after randomization
Length of hospital stay.
Within 30 days after randomization
Major bleeding
Délai: At 48 hours, 7 days, and 30 days after randomization
Incidence of major bleeding according to International Society on Thrombosis and Haemostasis criteria.
At 48 hours, 7 days, and 30 days after randomization
Bleeding requiring urgent medical intervention
Délai: At 48 hours, 7 days, and 30 days after randomization
Incidence of severe bleeding requiring urgent medical intervention.
At 48 hours, 7 days, and 30 days after randomization
Intracerebral bleeding
Délai: Within 7 days after randomization
Incidence of intracerebral bleeding.
Within 7 days after randomization

Autres mesures de résultats

Mesure des résultats
Description de la mesure
Délai
All-cause mortality at 12 months
Délai: At 12 months after randomization
Incidence of death from any cause.
At 12 months after randomization
At 12 months after randomization
Délai: At 12 months after randomization
Incidence of objectively confirmed recurrent pulmonary embolism.
At 12 months after randomization
Persistent dyspnea assessed using the modified Medical Research Council scale
Délai: At 3 months and 12 months after randomization
Persistent dyspnea assessed using the modified Medical Research Council scale.
At 3 months and 12 months after randomization
Functional status assessed using the Post-VTE Functional Status Scale
Délai: At 3 months and 12 months after randomization
Functional status assessed using the post-VTE functional status (PVFS) scale. Scores range from 0 to 4, where 0 indicates no functional limitations and 4 indicates severe functional limitations. Higher scores indicate worse functional status. Death before the scheduled assessment is recorded as grade D.
At 3 months and 12 months after randomization
Exercise tolerance assessed using the 6-minute walk test
Délai: At 3 months and 12 months after randomization
Exercise tolerance assessed using the 6-minute walk test, reported as distance walked in meters. A greater distance indicates better exercise tolerance.
At 3 months and 12 months after randomization
Persistent right ventricular dysfunction assessed by echocardiography
Délai: At 3 months and/or 12 months after randomization
Persistent right ventricular dysfunction according to echocardiography report, when performed as clinically indicated.
At 3 months and/or 12 months after randomization
Pulmonary embolism-specific quality of life assessed using the PEmb-QoL questionnaire
Délai: At 3 months and 12 months after randomization
Pulmonary embolism-specific health-related quality of life assessed using the Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire. The PEmb-QoL summary score ranges from 0 to 100, with higher scores indicating worse health-related quality of life.
At 3 months and 12 months after randomization
Health-related quality of life assessed using EQ-5D-5L
Délai: At 3 months and 12 months after randomization
Health-related quality of life assessed using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) instrument.
At 3 months and 12 months after randomization
Chronic thromboembolic pulmonary hypertension
Délai: At 12 months after randomization
Incidence of chronic thromboembolic pulmonary hypertension.
At 12 months after randomization
Health care resource utilization
Délai: During 12 months after randomization
Cost of health care resource utilization during the 12-month follow-up period.
During 12 months after randomization

Collaborateurs et enquêteurs

C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.

Les enquêteurs

  • Chercheur principal: Kristina Svennerholm, Sahlgrenska University Hospital / University of Gothenburg

Publications et liens utiles

La personne responsable de la saisie des informations sur l'étude fournit volontairement ces publications. Il peut s'agir de tout ce qui concerne l'étude.

Publications générales

Dates d'enregistrement des études

Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.

Dates principales de l'étude

Début de l'étude (Estimé)

1 décembre 2026

Achèvement primaire (Estimé)

31 janvier 2030

Achèvement de l'étude (Estimé)

31 janvier 2031

Dates d'inscription aux études

Première soumission

2 septembre 2026

Première soumission répondant aux critères de contrôle qualité

10 septembre 2026

Première publication (Réel)

14 septembre 2026

Mises à jour des dossiers d'étude

Dernière mise à jour publiée (Réel)

17 septembre 2026

Dernière mise à jour soumise répondant aux critères de contrôle qualité

14 septembre 2026

Dernière vérification

1 septembre 2026

Plus d'information

Termes liés à cette étude

Plan pour les données individuelles des participants (IPD)

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Description du régime IPD

De-identified individual participant data underlying the published results may be shared upon reasonable request after publication. Access will require approval by the sponsor and principal investigator, a scientifically sound proposal, scientific collaboration with the trial investigators, compliance with applicable ethical, regulatory, data protection, and consent requirements, and a signed data sharing agreement.

Délai de partage IPD

After publication of the trial results.

Critères d'accès au partage IPD

Reasonable request, subject to approval by the sponsor and principal investigator and applicable legal, ethical, and data protection requirements.

Type d'informations de prise en charge du partage d'IPD

  • PROTOCOLE D'ÉTUDE
  • SÈVE

Informations sur les médicaments et les dispositifs, documents d'étude

Étudie un produit pharmaceutique réglementé par la FDA américaine

Non

Étudie un produit d'appareil réglementé par la FDA américaine

Non

Ces informations ont été extraites directement du site Web clinicaltrials.gov sans aucune modification. Si vous avez des demandes de modification, de suppression ou de mise à jour des détails de votre étude, veuillez contacter register@clinicaltrials.gov. Dès qu'un changement est mis en œuvre sur clinicaltrials.gov, il sera également mis à jour automatiquement sur notre site Web .

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