Device Related ThrombosisNCT06523166
Direct Comparison of Cardiac CT With TEE to Evaluate Watchman FLX LAA Occluder Device Characteristics
A study testing Transesophageal echocardiography (TEE) and Cardiac CTA in people with Device Related Thrombosis and Peri-device Leak, run by University Hospitals Cleveland Medical Center at 5 sites in United States.
Trial summary
The current standard of care for patients who underwent left atrial appendage closure (LAAC) is to have follow-up transesophageal echocardiogram (TEE) for device surveillance. TEE is an ultrasound of the heart done by placing a probe in the esophagus under conscious sedation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Device Related Thrombosis, Peri-device Leak
- What is being tested?
- Transesophageal echocardiography (TEE) and Cardiac CTA
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 320 participants
- Where
- 5 sitesUnited States
- Study dates
- 27 Mar 2026to 1 Jan 2027
- Phase
- Interventional
- 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
Who may be able to join
- Subjects >18 years old planned to undergo LAAC
- eGFR ≥ 30 mL/min per 1.73 m2
Who cannot join
- Subjects below the age of 18
- non-English speaking subjects
- eGFR < 30 mL/min per 1.73 m2
- Subjects with history of contrast allergy
- Pregnant women
Trial locations and contacts
5 sites in 1 country. Contact the study team or a site near you to ask about taking part.
5 sites in 1 country
United States5 sites, 5 recruiting
- Recruiting
Sanger Heart & Vascular Institute- Atrium Health
Charlotte, North Carolina, 28277
Dana Amaro, MSN, RN, 704-355-4692, Dana.Amaro@atriumhealth.org
Markus Scherer, MD
- Not yet recruiting
University Hospitals Cleveland Medical Center
Cleveland, Ohio, 44106
Amy McKnight, RN, BSN, BCCV, 216-983-4896, Amy.McKnight@UHhospitals.org
Steven Filby, MD
- Not yet recruiting
Ohio State University Medical Center
Columbus, Ohio, 43210
Adrianne Miller, MS, CCRP, 614-688-8252, Adrianne.Miller3@osumc.edu
Mahmoud Houmssee, MD
- Not yet recruiting
Cedars Sinai
Los Angeles, California, 90048
Rhona Littman, 310-423-4387, *Littmanr@cshs.org
John Friedman, MD
- Not yet recruiting
St. Francis Hospital and Catholic Health
Roslyn, New York, 11576
Elizabeth Haag, RN, MPA, 516-622-4512, Elizabeth.Hagg@chsli.org
Omar Khlaique, MD
About this study
Official title: Direct Comparison of Cardiac CT With TEE to Evaluate Watchman FLX LAA Occluder Device Characteristics: A Multicenter Study
The current standard of care for patients who underwent left atrial appendage closure (LAAC) is to have follow-up transesophageal echocardiogram (TEE) for device surveillance. TEE is an ultrasound of the heart done by placing a probe in the esophagus under conscious sedation. It does not use contrast but can be cumbersome to patients as it involves placing a probe in the esophagus. Cardiac computerized tomography angiography (cardiac CTA) is a non-invasive imaging modality that involves the use of certain types of x-rays, contrast (dye) and special computers to generate accurate images of the heart. Participants in this study will undergo both TEE and CTA on the same day 90 days after their LAAC procedure.
Participants will be in this research study for a period of 1 year, starting from the day of their scheduled LAAC procedure. Participants will undergo a TEE at 90 days after their procedure which is the standard of care imaging study after LAAC. As part of this study, participants will also undergo a cardiac CTA at 90 days as well. Participants will have a routine follow-up visit following device placement as per standard of care as well as a brief phone "check in" at 1 year.
- Conditions
- Device Related Thrombosis, Peri-device Leak
- Being tested
- Transesophageal echocardiography (TEE), Cardiac CTA
- Keywords
- Watchman FLX, Left atrial appendage (LAA), Transesophageal echocardiography (TEE), Cardiac CTA
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transesophageal echocardiography (TEE)Procedure or surgery
TEE will be performed using a 3D probe. TEE images will be acquired at the standard 0, 45, 90, and 135 degree views along with a 3D acquisition encompassing the entire LAA, device, left pulmonary vein and lateral mitral annular landmarks.
Cardiac CTAProcedure or surgery
Cardiac CTA will be performed with ECG gating using systems with ≥ 64 detector rows and with temporal resolution that is at least 175 msec (rotation speed ≤ 350 msec for single source systems). Cardiac CTA images will be acquired for the entire cardiac cycle without ECG phase specific pulsing and with contrast appropriately timed for peak left atrial/arterial phase contrast enhancement. In addition, a targeted end systolic only delayed phase image set (45 seconds after the arterial phase scan and limited to the left atrium and appendage device) will be acquired.
| Study group | Role | What they receive |
|---|---|---|
| Left Atrial Appendage Occlusion (LAAC) with Watchman FLX. | Experimental | Patients who are status post LAAC using the Watchman FLX. Receives: Procedure: Transesophageal echocardiography (TEE); Procedure: Cardiac CTA |
What is being measured
The primary outcome is the main question the study is designed to answer.
LAA patency percentage associated with peri device leak (PDL) as measured by CT scan/TEE
Measured: 3 months post procedure
LAA patency percentage associated with intra device leak (IDL) as measured by CT scan/TEE.
Measured: 3 months post procedure
LAA patency percentage associated with a combination of both PDL and IDL as measured by CT scan/TEE.
Measured: 3 months post procedure
Number of detected device-related thrombus (DRT) as measured by CT scan/TEE.
Measured: 3 months
Secondary outcomes (5)
Average size of device measured in millimeters (mm)
Measured: 3 months
Percent of compression as measured by CT scan/TEE
Percent compression is comprised by dividing the device diameter over the device size represented as one single score.
Measured: 3 months
Average depth of implant measured in millimeters (mm)
Measured: 3 months
Average hypo-attenuated thickening (HAT) measured in millimeters (mm)
Measured: 3 months
Number of adverse events as measured by medical record
Adverse events can include respiratory failure requiring intubation or an esophageal perforation from TEE probe insertion or serious contrast related event including anaphylaxis during the CTA or acute renal failure (ARF) requiring dialysis within 7 days of the CTA.
Measured: Up to 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jul 2024
- Study start27 Mar 2026
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Device Related ThrombosisStudies of the same condition, open and under way.
- More trials run by University Hospitals Cleveland Medical CenterThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 320 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospitals Cleveland Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Boston Scientific Corporation
- Responsible party
- Principal investigator, Steven Filby, MD, University Hospitals Cleveland Medical Center
- Investigators
- Steven Filby, MD, Principal investigator, University Hospitals Cleveland Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06523166
- Sponsor's protocol ID
- STUDY20231491
- Status last verified
- Oct 2026
- First submitted
- 22 Jul 2024
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- 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 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Direct Comparison of Cardiac CT With TEE to Evaluate Watchman FLX LAA Occluder Device Characteristics: A Multicenter Study
- ClinicalTrials.gov ID
- NCT06523166
- Acronym / sponsor ID
- STUDY20231491
- Conditions
- Device Related Thrombosis, Peri-device Leak
- Keywords
- Watchman FLX, Left atrial appendage (LAA), Transesophageal echocardiography (TEE), Cardiac CTA
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 320 participants (estimated)
- Lead sponsor
- University Hospitals Cleveland Medical CenterUniversity, hospital or other
- Collaborators
- Boston Scientific Corporation
- Study start
- 27 Mar 2026 (actual)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jan 2027 (estimated)
- First posted
- 26 Jul 2024 (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 current standard of care for patients who underwent left atrial appendage closure (LAAC) is to have follow-up transesophageal echocardiogram (TEE) for device surveillance. TEE is an ultrasound of the heart done by placing a probe in the esophagus under conscious sedation. It does not use contrast but can be cumbersome to patients as it involves placing a probe in the esophagus. Cardiac computerized tomography angiography (cardiac CTA) is a non-invasive imaging modality that involves the use of certain types of x-rays, contrast (dye) and special computers to generate accurate images of the heart. Participants in this study will undergo both TEE and CTA on the same day 90 days after their LAAC procedure.
Participants will be in this research study for a period of 1 year, starting from the day of their scheduled LAAC procedure. Participants will undergo a TEE at 90 days after their procedure which is the standard of care imaging study after LAAC. As part of this study, participants will also undergo a cardiac CTA at 90 days as well. Participants will have a routine follow-up visit following device placement as per standard of care as well as a brief phone "check in" at 1 year.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Left Atrial Appendage Occlusion (LAAC) with Watchman FLX. | Experimental | Procedure: Transesophageal echocardiography (TEE), Procedure: Cardiac CTAPatients who are status post LAAC using the Watchman FLX. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Subjects >18 years old planned to undergo LAAC
- eGFR ≥ 30 mL/min per 1.73 m2
Key exclusion criteria (5 listed)
- Subjects below the age of 18
- non-English speaking subjects
- eGFR < 30 mL/min per 1.73 m2
- Subjects with history of contrast allergy
- Pregnant women
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 |
|---|---|---|
| Transesophageal echocardiography (TEE)TEE will be performed using a 3D probe. TEE images will be acquired at the standard 0, 45, 90, and 135 degree views along with a 3D acquisition encompassing the entire LAA, device, left pulmonary vein and lateral mitral annular landmarks. | Procedure or surgery | Left Atrial Appendage Occlusion (LAAC) with Watchman FLX. |
| Cardiac CTACardiac CTA will be performed with ECG gating using systems with ≥ 64 detector rows and with temporal resolution that is at least 175 msec (rotation speed ≤ 350 msec for single source systems). Cardiac CTA images will be acquired for the entire cardiac cycle without ECG phase specific pulsing and with contrast appropriately timed for peak left atrial/arterial phase contrast enhancement. In addition, a targeted end systolic only delayed phase image set (45 seconds after the arterial phase scan and limited to the left atrium and appendage device) will be acquired. | Procedure or surgery | Left Atrial Appendage Occlusion (LAAC) with Watchman FLX. |
Primary outcome
LAA patency percentage associated with peri device leak (PDL) as measured by CT scan/TEE
Time frame: 3 months post procedure
LAA patency percentage associated with intra device leak (IDL) as measured by CT scan/TEE.
Time frame: 3 months post procedure
LAA patency percentage associated with a combination of both PDL and IDL as measured by CT scan/TEE.
Time frame: 3 months post procedure
Number of detected device-related thrombus (DRT) as measured by CT scan/TEE.
Time frame: 3 months
5 secondary outcomes
Average size of device measured in millimeters (mm)
Time frame: 3 months
Percent of compression as measured by CT scan/TEE
Time frame: 3 months
Average depth of implant measured in millimeters (mm)
Time frame: 3 months
Average hypo-attenuated thickening (HAT) measured in millimeters (mm)
Time frame: 3 months
Number of adverse events as measured by medical record
Time frame: Up to 7 days
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 5 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.
Steven Filby, MD principal investigator
University Hospitals Cleveland Medical Center
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transesophageal echocardiography (TEE) and Cardiac CTA in people with Device Related Thrombosis and Peri-device Leak, run by University Hospitals Cleveland Medical Center at 5 sites in United States.
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 2 inclusion and 5 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: looking for participants now, as of the sponsor's last update on 5 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 5 sites in United States. 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?
Contact Amy McKnight, RN, BSN, BCCV (216-983-4896, Amy.McKnight@UHhospitals.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
LAA patency percentage associated with peri device leak (PDL) as measured by CT scan/TEE (time frame: 3 months post procedure). The study lists 4 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 5 Oct 2026.