ClinicalTrials.gg
RecruitingNCT04263038SAFE-SSPEUpdated May 22, 2026

Clinical Surveillance vs. Anticoagulation for Low-risk Patients With Isolated Subsegmental Pulmonary Embolism

A Phase 4 interventional study of Rivaroxaban and Placebo in Pulmonary Embolism, Embolism and Embolism and Thrombosis, sponsored by Drahomir Aujesky. Recruiting at 40 sites in 5 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-22.

Sponsored by Drahomir Aujesky · Phase 4, Interventional, and Treatment

From the registry’s dates

  • Started May 2020; still recruiting 6 years 5 months later.
Phase
Phase 4
Study type
Interventional
Enrollment
276
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The clinical significance of pulmonary embolism (PE) limited to the subsegmental pulmonary arteries, so called isolated subsegmental pulmonary embolism (SSPE), remains controversial. Whether isolated SSPE represents "true" PE, a clinically more benign form of PE, a physiologic lung clearing process, or a false positive result (artifact) is currently unclear and hence, whether patients with isolated SSPE benefit from anticoagulant treatment is uncertain. Despite growing evidence from observational studies that withholding anticoagulation may be a safe option in selected patients with isolated SSPE (i.e., those without concomitant deep vein thrombosis, cancer, etc.), most patients with isolated SSPE receive anticoagulant treatment, which is associated with an increased risk of bleeding. The overall objective of the randomized controlled SAFE-SSPE trial is to evaluate the efficacy and safety of clinical surveillance without anticoagulation compared to anticoagulation treatment in low-risk patients with isolated SSPE.

02

Conditions studied

  • Pulmonary Embolism
  • Embolism
  • Embolism and Thrombosis
  • Lung Diseases
  • Cardiovascular Diseases
  • Respiratory Tract Diseases
  • Venous Thromboembolism
  • Anticoagulant-induced Bleeding
  • Bleeding

Keywords

  • subsegmental pulmonary embolism
03

In context

Pulmonary Embolism

832 studies on the registry are indexed under Pulmonary Embolism; 171 are open to participants now.

This study's planned enrollment of 276 is above the median of 174 across 429 interventional studies indexed under Pulmonary Embolism.

Browse Pulmonary Embolism studies →

Lead sponsor

This is the only study on the registry with Drahomir Aujesky as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. as documented by signature
  2. Age ≥18 years
  3. Objective diagnosis of symptomatic or asymptomatic isolated SSPE

Exclusion criteria

Exclusion Criteria:

  1. Presence of leg deep vein thrombosis (DVT) or upper extremity DVT (subclavian vein or above)
  2. Active cancer, defined as cancer treated with surgery, chemotherapy, radiotherapy, or palliative care during the last 6 months
  3. ≥1 prior episode of unprovoked VTE (absence of a transient or permanent risk factor)
  4. Clinical instability (systolic blood pressure \<100 mm Hg or arterial Oxygen saturation \<92% at ambient air) at the time of presentation
  5. Active bleeding or at high risk of bleeding
  6. Severe renal failure ( \<30ml/min)
  7. Severe liver insufficiency ( B or C)
  8. Concomitant use of strong inhibitors or strong CYP3A4 inducers
  9. Known to rivaroxaban
  10. Need for therapeutic anticoagulation for another reason
  11. Therapeutic anticoagulation for >72 hours for any reason at the time of screening
  12. Hospitalized for >72 hours prior to the diagnosis of isolated SSP (hospital-acquired VTE)
  13. Known pregnancy or breast feeding (pregnancy test to be performed for women of )
  14. Lack of safe in women of childbearing potential
  15. Refusal or inability to provide
  16. Prior enrolment in this trial
Terms in these criteria, in plain language(7)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

Child-Pugh class

A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
276 participants (estimated)

Study arms

  • Active comparator
    Anticoagulation

    Patients in the anticoagulation group will receive rivaroxaban 15 mg twice daily for the first 21 days, followed by 20 mg once daily for an overall treatment duration of 90 days.

    Drug: Rivaroxaban

  • Placebo comparator
    No anticoagulation

    Patients in the group without anticoagulation will receive placebo twice daily for the first 21 days, followed by one tablet daily for an overall treatment duration of 90 days.

    Drug: Placebo

Interventions

  • Anticoagulation

  • DrugPlacebo

    Study drug without active agent

06

What researchers measure

Primary outcomes

  1. Recurrent venous thromboembolism

    Proportion of recurrent, clinically symptomatic, objectively confirmed venous thromboembolism (defined as recurrent fatal or nonfatal pulmonary embolism or lower limb deep vein thrombosis)

    Time frame: Within 90 days of randomization

Secondary outcomes

  1. Clinically significant bleeding

    Proportion of the composite of major and clinically relevant non-major bleeding

    Time frame: Within 90 days of randomization

  2. All-cause mortality

    Proportion of deaths (all causes of death will be considered)

    Time frame: Within 90 days of randomization

Other outcomes

  1. Health-related quality of life

    Pulmonary embolism related quality of life as assessed by the Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire

    Time frame: Within 90 days of randomization

  2. Functional status

    Functional status as assessed by the post-venous thromboembolism functional status scale

    Time frame: Within 90 days of randomization

  3. Initial length of stay (LOS)

    Defined as the time/date of discharge minus time/date of admission at the emergency department

    Time frame: Within 90 days of randomization

  4. Subsequent overall hospitalizations

    Number of overall hospitalizations

    Time frame: Within 90 days of randomization

  5. Emergency departments and physician outpatient visits

    Number of emergency department and physician outpatient visits

    Time frame: Within 90 days of randomization

  6. Return to work or usual activities

    Time (days) to return to work in workers and usual activities (household) in non-workers

    Time frame: Within 90 days of randomization

07

Study locations

29 of 40 sites recruiting
  • Cliniques Universitaires Saint-Luc
    Woluwe-Saint-Lambert, Brussels Capital 1200, Belgium
    Recruiting
    • Andrea Penaloza Baeza, Prof., MD · Contact
    • Andrea Penaloza Baeza, Prof., MD · Principal investigator
  • Centre hospitalier universitaire de Liege
    Liège, Belgium
    Recruiting
    • Raphaelle Lopez Iglesias, MD · Contact
    • Raphaelle Lopez Iglesias, MD · Principal investigator
  • The Ottawa Hospital
    Ottawa, Canada
    Recruiting
    • Marc Carrier, Prof. MD MSc · Contact
    • Marc Carrier, Prof. MD MSc · Principal investigator
  • Hôpital Bicêtre - APHP
    Le Kremlin-Bicêtre, Le Kremlin-Bicêtre 94270, France
    Recruiting
    • Mitja Jevnikar, MD · Contactmitja.jevnikar@aphp.fr · 0145213487
    • Mitja Jevnikar, MD · Principal investigator
  • Centre Hospitalier Regional Et Universitaire De Brest
    Brest, France
    Recruiting
    • Francis Couturaud, Prof. MD · Contact
    • Francis Couturaud, Prof., MD · Principal investigator
  • CHU Gabriel-Montpied
    Clermont-Ferrand, France
    Recruiting
    • Jeannot Schmidt, Prof., MD · Contact
    • Jeannot Schmidt, Prof., MD · Principal investigator
  • Centre Hospitalier Universitaire De Dijon
    Dijon, France
    Recruiting
    • Nicolas Falvo, MD · Contact
    • Nicolas Falvo, MD · Principal investigator
  • Hospital Edouard Herriot
    Lyon, France
    Recruiting
    • Judith Catella, MD · Contact
    • Judith Catella, MD · Principal investigator
  • Hôpitaux universitaires de Marseille Timone AP-HM
    Marseille, France
    Recruiting
    • Gabrielle Sarlon, Prof., MD · Contact
    • Gabrielle Sarlon, Prof., MD · Principal investigator
  • CHU De Rouen
    Rouen, France
    Recruiting
    • Sébastien Miranda, MD · Contact
    • Sébastien Miranda, MD · Principal investigator
  • CHU ST Etienne - Hôpital Nord
    Saint-Priest-en-Jarez, France
    Recruiting
    • Laurent Bertoletti, Prof., MD · Contact
    • Laurent Bertoletti, Prof., MD · Principal investigator
  • Albert Schweitzer Ziekenhuis Dordrecht
    Dordrecht, Netherlands
    Recruiting
    • P.E. Westerweel, MD · Contact
    • P.E. Westerweel, MD · Principal investigator
  • Medisch Spectrum Twente
    Enschede, Netherlands
    Recruiting
    • H.P.A.A. van Veen, MD · Contact
    • H.P.A.A. van Veen, MD · Principal investigator
  • Leiden University Medical Center
    Leiden, Netherlands
    Recruiting
    • F. A. Klok, Prof. MD PhD · Contact
    • F. A. Klok, Prof., MD, PhD · Principal investigator
  • Erasmus Universitair Medisch Centrum
    Rotterdam, Netherlands
    Withdrawn

    Not enrolling at this site — choose another above.

  • Haaglanden Medisch Centrum
    The Hague, Netherlands
    Withdrawn

    Not enrolling at this site — choose another above.

  • Isala Klinieken Zwolle
    Zwolle, Netherlands
    Recruiting
    • M. F. Boosma, MD · Contact
    • M. F. Boosma, MD · Principal investigator
  • Cantonal Hospital of Liestal
    Liestal, Basel, Switzerland
    Recruiting
    • Jörg Leuppi, Prof. MD PhD · Contact
    • Jörg Leuppi, Prof., MD, PhD · Principal investigator
  • Cantonal Hospital of Aarau
    Aarau, Canton of Aargau, Switzerland
    Recruiting
    • Philippe Schütz, Prof. MD MPH · Contact
    • Philippe Schütz, Prof., MD, MPH · Principal investigator
  • University Hospital Inselspital
    Bern, Canton of Bern 3010, Switzerland
    Recruiting
    • Drahomir Aujesky, Prof. MD MSc · Contact
    • Drahomir Aujesky, Prof., MD, MSc · Principal investigator
  • Hospital of Bienne
    Biel/Bienne, Canton of Bern, Switzerland
    Recruiting
    • Daniel Genné, Prof. MD · Contact
    • Daniel Genné, Prof., MD · Principal investigator
  • Cantonal Hospital of Fribourg
    Fribourg, Canton of Fribourg, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Lucerne
    Lucerne, Canton of Lucerne, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Olten
    Olten, Canton of Solothurn, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of St. Gallen
    Sankt Gallen, Canton of St. Gallen, Switzerland
    Recruiting
    • Claudio S. Rüegg, MD · Contact
    • Claudio S. Rüegg, MD · Principal investigator
  • University Hospital of Lausanne
    Lausanne, Canton of Vaud, Switzerland
    Recruiting
    • Marie Méan, MD MER · Contact
    • Marie Méan, MD, MER · Principal investigator
  • Hospital of Nyon
    Nyon, Canton of Vaud, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Winterthur
    Winterthur, Canton of Zurich, Switzerland
    Recruiting
    • Bettina Portocarrero, MD · Contact
    • Bettina Portocarrero, MD · Principal investigator
  • Triemli Hospital
    Zurich, Canton of Zurich, Switzerland
    Recruiting
    • Lars Huber, PD MD · Contact
    • Lars Huber, PD, MD · Principal investigator
  • University Hospital Zürich
    Zurich, Canton of Zurich, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Frauenfeld
    Frauenfeld, Thurgau, Switzerland
    Recruiting
    • Andreas Kistler, PD MD · Contact
    • Andreas Kistler, PD, MD · Principal investigator
  • Hospital of Sion
    Sion, Valais, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Uri
    Altdorf, Switzerland
    Withdrawn

    Not enrolling at this site — choose another above.

  • Cantonal Hospital of Baden
    Baden, Switzerland
    Recruiting
    • Maria Wertli, Prof. MD · Contact
    • Maria Wertli, Prof., MD · Principal investigator
  • University Hospital of Basel
    Basel, Switzerland
    Recruiting
    • Roland Bingisser, Prof., MD · Contact
    • Roland Bingisser, Prof., MD · Principal investigator
  • Tiefenau Hospital
    Bern, Switzerland
    Completed

    Not enrolling at this site — choose another above.

  • Regional Hospital of Emmental
    Burgdorf, Switzerland
    Recruiting
    • Robert Escher, PD Dr. MD · Contact
    • Robert Escher, PD, MD · Principal investigator
  • Hospital of Delémont
    Delémont, Switzerland
    Terminated

    Not enrolling at this site — choose another above.

  • Geneva University Hospital
    Geneva, Switzerland
    Recruiting
    • Marc Righini, Prof. MD · Contact
    • Marc Righini, Prof., MD · Principal investigator
  • Hospital of Neuchâtel
    Neuchâtel, Switzerland
    Recruiting
    • Jacques Donzé, Prof. MD MSc · Contact
    • Jacques Donzé, Prof., MD, MSc · Principal investigator
08

References and documents

Publications

  • Baumgartner C, Klok FA, Carrier M, Limacher A, Moor J, Righini M, Beer JH, Peluso M, Rakovic D, Huisman MV, Aujesky D. Clinical Surveillance vs. Anticoagulation For low-risk patiEnts with isolated SubSegmental Pulmonary Embolism: protocol for a multicentre randomised placebo-controlled non-inferiority trial (SAFE-SSPE). BMJ Open. 2020 Nov 19;10(11):e040151. doi: 10.1136/bmjopen-2020-040151. PubMed 33444199 ↗

Individual participant data

Plan to share: Yes — After publication of the study results, a de-identified patient-level data set relating to the primary publication along with the latest version of the study protocol, the informed consent form, the statistical analysis plan, the code used for the analyses, and the Data Management and Quality Plan describing all data management aspects of the study will be made publicly available for replication of the study results and secondary data analyses in the Bern Open Repository and Information System (BORIS) Research Data, an online non-commercial data repository that meets Swiss National Science Foundation requirements for FAIR Data Principles (www.force11.org/group/fairgroup/fairprinciples)

Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Analytic code

Time frame: After publication of the study results

Access criteria: Data will be publicly available for replication of the study results and secondary data analyses in the Bern Open Repository and Information System (BORIS) Research Data

Data sharing details ↗ · www.boris.unibe.ch

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started May 2020 (actual). Primary completion is estimated for May 2028, 96 months after the start.

Of 24 phase 4 interventional studies under Pulmonary Embolism, half reached primary completion within 47 months of starting (the median), counting those still running; a quarter within 32 and three quarters within 82. This study's planned 96 months is above that.

How these figures are worked out, and which studies are left out of them.

Registered
Feb 4, 2020
First posted
Feb 10, 2020
StartActual
May 15, 2020
Primary completionEst.
May 2028
CompletionEst.
May 2028
Last update
May 22, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on May 22, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04263038
Lead sponsor
Drahomir Aujesky
Collaborators
University of Bern, Schweizerischer Nationalfonds, Leiden University Medical Center, The Ottawa Hospital, Bayer
Responsible party
Drahomir Aujesky (Prof. Dr., MD, MSc, Insel Gruppe AG, University Hospital Bern) — Sponsor-investigator
First posted
Feb 10, 2020
Start date
May 15, 2020
Primary completion
May 2028 (estimated)
Completion
May 2028 (estimated)
Last update
May 22, 2026

Study contacts

Drahomir Aujesky, Prof. MD MSc
Contact
SAFE-SSPE@insel.ch
+41 31 632 88 84
Tobias Tritschler, Dr. MD MSc
Contact
SAFE-SSPE@insel.ch
+41 31 63 2 01 46
Drahomir Aujesky, Prof. MD MSc
study director · Inselspital, Bern University Hospital, University of Bern

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Rivaroxaban

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