Non-valvular Atrial Fibrillation (AF)NCT07262255
WATCHMAN FLX Pro European Registry
An observational study of Non-valvular Atrial Fibrillation (AF) and Left Atrial Appendage Closure, run by Boston Scientific Corporation at 20 sites in 6 countries.
Trial summary
The WATCHMAN FLX Pro European registry is intended to gather real world clinical data for patients undergoing left atrial appendage closure (LAAC) with the WATCHMAN FLX™ Pro device. In a subregistry with approximately 300 patients, it is intended to use the VersaCross Connect™ LAAC Access Solution. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Non-valvular Atrial Fibrillation (AF), Left Atrial Appendage Closure
- What is being tested?
- Left atrial appendage closure
- Type of treatment
- Medical device
- How many people
- 189 participants
- Where
- 20 sitesin 6 countries
- Study dates
- 17 Dec 2025to Sep 2028
- How long will I take part?
- 12 Months
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Hospital
Who may be able to join
- Subject is attempted to be treated with the WATCHMAN FLX™ Pro LAAC device.
- Subject has non-valvular atrial fibrillation (i.e., atrial fibrillation in the absence of moderate or greater mitral stenosis or a mechanical heart valve) and is clinically indicated for a WATCHMAN FLX™ Pro LAAC device, per the Instructions for Use (IFU).
- Subject or legal representative who are willing and capable of providing informed consent.
- Subject is able and willing to return for required follow-up visits and examinations.
- Subject whose age is 18 years or above, or who is of legal age to give informed consent specific to state and national law.
Who cannot join
- Subject has a documented life expectancy of less than 12 months.
- Subject who is currently enrolled in another investigational study or registry except when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments.
- Intracardiac thrombus is present.
- An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present.
- The LAA anatomy will not accommodate a Closure Device.
- Subject has a known hypersensitivity or contraindications according to IFU.
- Subject is of childbearing potential and is, or plans to become, pregnant during the time of the study.
Trial locations and contacts
20 sites in 6 countries.
20 sites in 6 countries
Germany7 sites
Herz-und Diabeteszentrum Nordrhein-Westfalen
Bad Oeynhausen, 32545
Charite, Campus Benjamin Franklin
Berlin, 12203
Kath Krankenhaus St Johann Nepomuk
Erfurt, 99097
Asklepios Klinik Saint Georg
Hamburg, 20099
Asklepios Klinik Nord Heidberg
Hamburg, 22417
Asklepios Klinik Altona
Hamburg, 22763
Universitaetsklinikum Schleswig-Holstein
Lübeck, 23582
Spain5 sites
Hospital de Leon
León, 24071
Clinica Universidad de Navarra
Pamplona, 31008
Complejo Hospitalario de Pontevedra
Pontevedra, 36001
Complejo Hospitalario Universitario de Pontevedra
Pontevedra, 36001
Hospital Clinico Salamanca
Salamanca, 37007
Italy3 sites
Azienda Ospedaliero Universitaria Policlinico "G. Rodolico-San Marco
Catania, 95123
Centro Cardiologico Monzino
Milan, 20138
Ospedale Sacro Cuore Don Calabria
Verona, 37126
Denmark2 sites
Aarhus University Hospital
Aarhus, 8200
Rigshospitalet Copenhagen
Copenhagen, 2100
Switzerland2 sites
University Hospital Basel
Basel, 4031
INSELSPITAL - Universitätsspital Bern
Bern, CH-3010
About this study
The WATCHMAN FLX Pro European registry is intended to gather real world clinical data for patients undergoing left atrial appendage closure (LAAC) with the WATCHMAN FLX™ Pro device. In a subregistry with approximately 300 patients, it is intended to use the VersaCross Connect™ LAAC Access Solution.
- Being tested
- Left atrial appendage closure
- Keywords
- LAAC
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Left atrial appendage closureDevice
The WATCHMAN FLX Pro LAAC Technology is intended to prevent thrombus embolization from the left atrial appendage and reduce the risk of life-threatening bleeding events in adult patients with non-valvular atrial fibrillation who are eligible for anticoagulation therapy or who have a contraindication to anticoagulation therapy.
The VersaCross Connect™ LAAC Access Solution is indicated for the percutaneous introduction of various types of cardiovascular catheters and guidewires to all heart chambers, including the left atrium via transseptal perforation / puncture.
| Study group | Role | What they receive |
|---|---|---|
| WATCHMAN FLX Pro | This arm is intended to gather real world clinical data for patients undergoing left atrial appendage closure (LAAC) with the WATCHMAN FLX™ Pro device.
Approximately 300 patients undergo the LAAC procedure in conjunction with the use of the VersaCross Connect™ LAAC Access Solution. Receives: Device: Left atrial appendage closure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with a safety event treated with the WATCHMAN FLX Pro
Proportion of subjects with one or more of the following events between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later: all-cause death, ischemic stroke, systemic embolism, or device or procedure related events requiring open cardiac surgery or major endovascular intervention such as pseudoaneurysm repair, AV fistula repair, or other major endovascular repair.
Percutaneous catheter drainage of pericardial effusions, snaring of an embolized device, thrombin injection to treat femoral pseudoaneurysm and minor nonsurgical treatments of access site complications are excluded from this endpoint.
Measured: Between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later
Number of participants with a safety event treated with the VersaCross Connect™ LAAC Access Solution
Proportion of subjects with one or more of the following events between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later:
For all enrolled subjects, who had an attempt to insert the VersaCross Connect™ LAAC Access Solution device, the composite rate of all-cause death, all stroke, systemic embolism, pericardial effusion resulting in interventions*, and ISTH major bleeding.
*Pericardial effusion/tamponade requiring pericardiocentesis or surgery to treat
Measured: Between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later
Number of participants with a successful VersaCross Connect™ LAAC Access Solution treatment
VersaCross Connect™ LAAC Access Solution acute procedural success: Acute Procedural Success is defined as transseptal puncture success (VersaCross RF-wire crossing into left atrium).
Measured: Completion of transseptal puncture
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2025
- Study start17 Dec 2025
- Primary completionAug 2027 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Non-valvular Atrial Fibrillation (AF)Studies of the same condition, open and under way.
- More trials run by Boston Scientific CorporationThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 189 participants (actual)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- Boston Scientific Corporation
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Marek Grygier, Prof. MD, PHD, Principal investigator, Uniwersytecki Szpital Kliniczny w PoznaniuArian Sultan, Prof. MD, Principal investigator, Asklepios Klinik Saint Georg
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07262255
- Sponsor's protocol ID
- S2603
- Status last verified
- Oct 2026
- First submitted
- 17 Nov 2025
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- WATCHMAN FLX Pro European Registry
- ClinicalTrials.gov ID
- NCT07262255
- Acronym / sponsor ID
- S2603
- Keywords
- LAAC
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 189 participants (actual)
- Lead sponsor
- Boston Scientific CorporationIndustry (pharma, biotech, devices)
- Study start
- 17 Dec 2025 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 3 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The WATCHMAN FLX Pro European registry is intended to gather real world clinical data for patients undergoing left atrial appendage closure (LAAC) with the WATCHMAN FLX™ Pro device. In a subregistry with approximately 300 patients, it is intended to use the VersaCross Connect™ LAAC Access Solution.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 12 Months
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| WATCHMAN FLX Pro | – | Device: Left atrial appendage closureThis arm is intended to gather real world clinical data for patients undergoing left atrial appendage closure (LAAC) with the WATCHMAN FLX™ Pro device. Approximately 300 patients undergo the LAAC procedure in conjunction with the use of the VersaCross Connect™ LAAC Access Solution. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Hospital
Key inclusion criteria (5 listed)
- Subject is attempted to be treated with the WATCHMAN FLX™ Pro LAAC device.
- Subject has non-valvular atrial fibrillation (i.e., atrial fibrillation in the absence of moderate or greater mitral stenosis or a mechanical heart valve) and is clinically indicated for a WATCHMAN FLX™ Pro LAAC device, per the Instructions for Use (IFU).
- Subject or legal representative who are willing and capable of providing informed consent.
- Subject is able and willing to return for required follow-up visits and examinations.
- Subject whose age is 18 years or above, or who is of legal age to give informed consent specific to state and national law.
Key exclusion criteria (7 listed)
- Subject has a documented life expectancy of less than 12 months.
- Subject who is currently enrolled in another investigational study or registry except when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments.
- Intracardiac thrombus is present.
- An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present.
- The LAA anatomy will not accommodate a Closure Device.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Left atrial appendage closureThe WATCHMAN FLX Pro LAAC Technology is intended to prevent thrombus embolization from the left atrial appendage and reduce the risk of life-threatening bleeding events in adult patients with non-valvular atrial fibrillation who are eligible for anticoagulation therapy or who have a contraindication to anticoagulation therapy. The VersaCross Connect™ LAAC Access Solution is indicated for the percutaneous introduction of various types of cardiovascular catheters and guidewires to all heart chambers, including the left atrium via transseptal perforation / puncture. | Device | WATCHMAN FLX Pro |
Primary outcome
Number of participants with a safety event treated with the WATCHMAN FLX Pro
Time frame: Between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later
Proportion of subjects with one or more of the following events between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later: all-cause death, ischemic stroke, systemic embolism, or device or procedure related events requiring open cardiac surgery or major endovascular intervention such as pseudoaneurysm repair, AV fistula repair, or other major endovascular repair. Percutaneous catheter drainage of pericardial effusions, snaring of an embolized device, thrombin injection to treat femoral pseudoaneurysm and minor nonsurgical treatments of access site complications are excluded from this endpoint.
Number of participants with a safety event treated with the VersaCross Connect™ LAAC Access Solution
Time frame: Between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later
Proportion of subjects with one or more of the following events between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later: For all enrolled subjects, who had an attempt to insert the VersaCross Connect™ LAAC Access Solution device, the composite rate of all-cause death, all stroke, systemic embolism, pericardial effusion resulting in interventions*, and ISTH major bleeding. *Pericardial effusion/tamponade requiring pericardiocentesis or surgery to treat
Number of participants with a successful VersaCross Connect™ LAAC Access Solution treatment
Time frame: Completion of transseptal puncture
VersaCross Connect™ LAAC Access Solution acute procedural success: Acute Procedural Success is defined as transseptal puncture success (VersaCross RF-wire crossing into left atrium).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marek Grygier, Prof. MD, PHD principal investigator
Uniwersytecki Szpital Kliniczny w Poznaniu
Arian Sultan, Prof. MD principal investigator
Asklepios Klinik Saint Georg
20 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Non-valvular Atrial Fibrillation (AF) and Left Atrial Appendage Closure, run by Boston Scientific Corporation at 20 sites in 6 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 20 sites in Germany, Spain, Italy, Denmark, Switzerland and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with a safety event treated with the WATCHMAN FLX Pro (time frame: Between the time of procedure and within 7 days following the procedure or by hospital discharge, whichever is later). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026.