Post Operative Atrial FibrillationNCT06989775
BoxX-NoAF Clinical Trial
A study testing Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System in people with Post Operative Atrial Fibrillation and Atrial Fibrillation, Postoperative, run by AtriCure, Inc. at 37 sites in 2 countries.
Trial summary
Post Operative Atrial Fibrillation (POAF) is the most common complication of cardiac surgery. POAF incidence can exceed 50% depending on the patient baseline characteristics and surgery type. Patients with POAF tend to have worse acute and long-term clinical outcomes. Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Post Operative Atrial Fibrillation, Atrial Fibrillation, Postoperative
- What is being tested?
- Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 960 participants
- Where
- 37 sitesin 2 countries
- Study dates
- 24 Oct 2025to Dec 2029
- 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 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Planned and clinically indicated for cardiac surgical procedure requiring cardiac bypass and opening of the pericardium
- Age ≥ 65 years and CHA2DS2-VASc ≥ 3
Who cannot join
- Documented history of atrial fibrillation or atrial flutter anytime prior to the cardiac surgery
- Prior procedure involving opening the pericardium or entering the pericardial space
- Patients undergoing off-pump surgery
- Prior LAA occlusion, exclusion, or removal (surgical or percutaneous)
- Presence of a permanent pacemaker
- Infiltrative cardiomyopathies (i.e. amyloidosis)
Show all 20Show fewer
- Planned cardiac surgical procedure using non-sternotomy approaches
- Patients whose planned procedure is a heart transplant or implantation of any long-term ventricular assist devices
- Presence of ventricular arrhythmia
- Active endocarditis
- NYHA Class IV heart failure symptoms
- Preoperative need for an intra-aortic ballon pump or intravenous inotropes
- Active systemic infection at the time of cardiac surgery requiring antibiotics
- Known allergy to Nitinol or nickel sensitivity
- Known medical condition with expected survival of less than 1 year
- Other comorbidities that in the Investigator's opinion make the subject unsuitable candidate to complete the protocol required intervention or visits
- Current enrollment in an investigation or trial or an investigational devices or investigational drug that would interfere with this trial
- Mental impairment or other psychiatric conditions which may not allow the patient to understand the nature, significance, and scope of the trial.
- Pregnancy
- Known severe symptomatic carotid disease
Trial locations and contacts
37 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
37 sites in 2 countries
United States33 sites, 32 recruiting
- Recruiting
University of Michigan
Ann Arbor, Michigan, 48109
Amanda Kasperek, 734-936-9664, kasperea@med.umich.edu
Matthew Romano, MD
- Recruiting
Emory University
Atlanta, Georgia, 30308
Jayne Thompson, 404-285-1895, sjdanle@emory.edu
Jeffrey Miller, MD
- Recruiting
Piedmont Hospital
Atlanta, Georgia, 30309
Brittney Truss, 404-695-7023, Brittney.Truss@piedmont.org
Gigi Davis, Gigi.Davis@piedmont.org
- Recruiting
St David's HealthCare
Austin, Texas, 78705
Shir Yelovitch, 512-459-8753, Shir.Yelovitch@stdavids.com
Faraz Kerendi, MD
- Recruiting
MedStar Health Research Institute
Baltimore, Maryland, 21218
Keith Moyer, 410-554-6550, keith.t.moyer@medstar.net
Brian Bethea, MD
- Recruiting
Charleston Area Medical Center
Charleston, West Virginia, 25304
Jordan Campanelli, 304-388-9889, Jordan.Campanelli@vandaliahealth.org
Kaylea Hoffman, 304-388-9889, Kaylea.Hoffman@vandaliahealth.org
- Recruiting
Northwestern Memorial Hospital
Chicago, Illinois, 60611
Meredith Chappell, 312-926-7312, Meredith.Chappell@nm.org
Leonie Mbouguen, Leonieluciano.mbouguen@nm.org
- Recruiting
Bethesda North Hospital
Cincinnati, Ohio, 45242
Tia Little, 513-865-5218, tia_little@trihealth.com
Adeteju Mowo-Wale, adeteju_mowo-wale@trihealth.com
- Recruiting
Morton Plant Hospital - BayCare Health System, Inc.
Clearwater, Florida, 33759
Arielle Campos, 813-533-1418, arielle.campos@baycare.org
John Ofenloch, MD
- Recruiting
St. Joseph's Hospital - BayCare Health System, Inc.
Clearwater, Florida, 33759
Arielle Campos, 813-533-1418, arielle.campos@baycare.org
Andrew Sherman, MD
- Recruiting
Cleveland Clinic Foundation
Cleveland, Ohio, 44195
Anna Marie Simmons, 216-444-0379, simmona8@ccf.org
Laurie Ann Moennich, moennil@ccf.org
- Recruiting
Baylor Research Institute - Baylor Scott and White Research Institute
Dallas, Texas, 75204
Jennifer Wei, 469-814-4878, Jennifer.Wei@BSWHealth.org
Kelley Hutcheson, MD
- Recruiting
Corewell Health
Grand Rapids, Michigan, 49503
Denise Wittenbach, BSN RN, CCRC, 616-391-2066, denise.wittenbach@corewellhealth.org
Charles Willekes, MD
- Recruiting
St. Bernards Medical Center
Jonesboro, Arkansas, 72401
Cary Ball, 870-207-3812, cary@cargresearch.com
Jay Bhama, MD
- Recruiting
Norton Healthcare
Louisville, Kentucky, 40205
Gretchen Holz, 502-629-2858, gretchen.holz@nortonhealthcare.org
System Research, 502-629-2858, Systemresearch@nortonhealthcare.org
- Recruiting
Northwell Health
Manhasset, New York, 11030
Sarah Alfaro, 516-562-2123, salfaro1@northwell.edu
Lily Greenwald, lgreenwald@northwell.edu
- Recruiting
Wellstar Health System
Marietta, Georgia, 30062
Autumn Lee, 470-793-4040, autumn.lee@wellstar.org
Theresa Luu, MD
- Recruiting
Naples Comprehensive Health
Naples, Florida, 34102
Megan Dalziel, 239-624-8113, megan.dalziel@nchmd.org
Thomas Caranasos, MD
- Recruiting
Centennial Medical Center
Nashville, Tennessee, 37203
Michael Brown, 615-342-6900, michael.brown@hcahealthcare.com
Seenu Reddy, MD
- Recruiting
Ascension Saint Thomas
Nashville, Tennessee, 37205
Cassie Hodges, 615-222-3815, cassie.hodges@ascension.org
Amber Edwards, MD
- Not yet recruiting
New York Presbyterian Hospital/Columbia University Irving Medical Center
New York, New York, 10032
Bo Lu, 212-305-3009, bl2699@cumc.columbia.edu
Hiroo Takayama, MD
- Recruiting
Orlando Health, Inc.
Orlando, Florida, 32806
George Ngo, 321-843-9657, george.ngo@orlandohealth.com
Anthony Rongione, MD
- Recruiting
Allegheny-Singer Research Institute
Pittsburgh, Pennsylvania, 15212
Tracy Spirk, 412-359-4025, tracy.spirk@ahn.org
Stephen Bailey, MD
- Recruiting
Mayo Clinic
Rochester, Minnesota, 55905
Levi Disrud, 507-422-5241, disrud.levi@mayo.edu
Tata Lukman, tata.lukman@mayo.edu
- Withdrawn
Methodist San Antonio
San Antonio, Texas, 78229
- Recruiting
Sharp Memorial Hospital
San Diego, California, 92123
Kaitlynn Lewis, 858-244-6886, klewis@sdcardiac.com
Donna Small, DSmall@sdcardiac.com
- Recruiting
Sarasota Memorial Hospital
Sarasota, Florida, 34239
Marisa Mamazza, 941-262-5802, Marisa-mamazza@smh.com
Tina Ryan, 941-262-5801, Tina-ryan@smh.com
- Recruiting
Honor Health
Scottsdale, Arizona, 85258
Kiki Miguel, 763-236-9237, mmiguel@honorhealth.com
Zain Khalpey, MD
- Recruiting
BJC Healthcare (Washington University)
St Louis, Missouri, 63110
Brenna Reilly, 314-747-0707, brennar@wustl.edu
Jamie Rolando, jamier@wustl.edu
- Recruiting
Adventist Health St. Helena
St. Helena, California, 94574
Shalese Canby, 707-967-5959, CanbySR@ah.org
Aaron Kime, MD
- Recruiting
Promedica Toledo Hospital
Toledo, Ohio, 43614
Vanessa Young, 419-291-3757, Vanessa.Young@ProMedica.org
Alexander Ghannam, MD
- Recruiting
Aspirus Hospital
Wausau, Wisconsin, 54401
Debra Waters, 715-847-2273, Debra.Waters@aspirus.org
John Johnkoski, MD
- Recruiting
Trinity Health
Ypsilanti, Michigan, 48197
Megan Thompson, 734-712-5451, megan_thompson@michiganheart.com
Robert Lyons, MD
Canada4 sites, 4 recruiting
- Recruiting
Hamilton General Hospital
Hamilton, Ontario, L8L 2X2
Courtney Mullen, 905-521-2100 ext. 44342, courtney.mullen@phri.ca
Sara Eskandarian, Sara.Eskandarian@phri.ca
- Recruiting
London Health Sciences Centre, University Hospital
London, Ontario, N6A 5A5
Stephanie Fox, 519-685-8500 ext. 35031, stephanie.fox@lhsc.on.ca
Michael Chu, MD
- Recruiting
Montreal Heart Institute
Montreal, Quebec, H1T 1C8
Ester Cisneros-Aquilera, 514-376-3330 ext. 4046, Ester.Cisneros-Aguilera@icm-mhi.org
Alexandre Bergeron, alexandre.bergeron.icm@icm-mhi.org
- Recruiting
Royal Columbian Hospital
New Westminster, British Columbia, V3L 3W7
Korey Sutherland, 604-520-4253, Korey.Sutherland@fraserhealth.ca
Hossein Shayan, MD
About this study
Official title: EnCompass Clamp and the AtriClip in Box Lesion and Left Atrial Appendage EXclusion Procedure for the Prevention of New Onset of Atrial Fibrillation
Post Operative Atrial Fibrillation (POAF) is the most common complication of cardiac surgery. POAF incidence can exceed 50% depending on the patient baseline characteristics and surgery type. Patients with POAF tend to have worse acute and long-term clinical outcomes. BoxX-NoAF is a randomized trial to evaluate if prophylactic ablation and exclusion of the Left Atrial Appendage at the time of other routine cardiac surgery can reduce the incidence of post operative AF and clinical AF during long term follow up in patients who have not yet developed AF but are at risk.
- Being tested
- Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System
- Keywords
- Post operative AF, Clinical AF
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion SystemDevice
Box lesion ablation with the Isolator Synergy EnCompass Clamp System and LAAE using the AtriClip LAA Exclusion System at the time of planned cardiac surgery
| Study group | Role | What they receive |
|---|---|---|
| Treatment | Experimental | Index cardiac surgery + Ablation + Left Atrial Appendage Exclusion with AtriClip Receives: Device: Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System |
| Control | No intervention | Index cardiac surgery only |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary Effectiveness Endpoint
The occurrence of clinically relevant post operative AF (POAF)
Measured: 30 days post index cardiac surgical procedure
Primary Safety Endpoint
The composite of the following events:
- All cause Mortality
- Reoperation
- Deep sternal wound infection
- Permanent stroke
- Prolonged ventilation
- Renal failure
- 30-day readmission
- Atypical left atrial flutter
- Phrenic nerve palsy
- Major Bleeding
Measured: 30 days post index cardiac surgical procedure
Secondary outcomes (1)
Powered Secondary Effectiveness Endpoint
The time to first occurrence of clinical atrial fibrillation from 30 days after index cardiac surgical procedure through 3-years
Measured: 3 years post index cardiac surgical procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2025
- Study start24 Oct 2025
- Primary completionFeb 2027 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Post Operative Atrial FibrillationStudies of the same condition, open and under way.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 960 participants (estimated)
Sponsor and investigators
- Lead sponsor
- AtriCure, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06989775
- Sponsor's protocol ID
- CP-2024-02
- Status last verified
- Jun 2026
- First submitted
- 12 May 2025
- Last updated
- 7 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- EnCompass Clamp and the AtriClip in Box Lesion and Left Atrial Appendage EXclusion Procedure for the Prevention of New Onset of Atrial Fibrillation
- ClinicalTrials.gov ID
- NCT06989775
- Acronym / sponsor ID
- CP-2024-02
- Keywords
- Post operative AF, Clinical AF
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 960 participants (estimated)
- Lead sponsor
- AtriCure, Inc.Industry (pharma, biotech, devices)
- Study start
- 24 Oct 2025 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 25 May 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.
Post Operative Atrial Fibrillation (POAF) is the most common complication of cardiac surgery. POAF incidence can exceed 50% depending on the patient baseline characteristics and surgery type. Patients with POAF tend to have worse acute and long-term clinical outcomes. BoxX-NoAF is a randomized trial to evaluate if prophylactic ablation and exclusion of the Left Atrial Appendage at the time of other routine cardiac surgery can reduce the incidence of post operative AF and clinical AF during long term follow up in patients who have not yet developed AF but are at risk.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Treatment | Experimental | Device: Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion SystemIndex cardiac surgery + Ablation + Left Atrial Appendage Exclusion with AtriClip |
| Control | No intervention | –Index cardiac surgery only |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (2 listed)
- Planned and clinically indicated for cardiac surgical procedure requiring cardiac bypass and opening of the pericardium
- Age ≥ 65 years and CHA2DS2-VASc ≥ 3
Key exclusion criteria (20 listed)
- Documented history of atrial fibrillation or atrial flutter anytime prior to the cardiac surgery
- Prior procedure involving opening the pericardium or entering the pericardial space
- Patients undergoing off-pump surgery
- Prior LAA occlusion, exclusion, or removal (surgical or percutaneous)
- Presence of a permanent pacemaker
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 |
|---|---|---|
| Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion SystemBox lesion ablation with the Isolator Synergy EnCompass Clamp System and LAAE using the AtriClip LAA Exclusion System at the time of planned cardiac surgery | Device | Treatment |
Primary outcome
Primary Effectiveness Endpoint
Time frame: 30 days post index cardiac surgical procedure
The occurrence of clinically relevant post operative AF (POAF)
Primary Safety Endpoint
Time frame: 30 days post index cardiac surgical procedure
The composite of the following events: * All cause Mortality * Reoperation * Deep sternal wound infection * Permanent stroke * Prolonged ventilation * Renal failure * 30-day readmission * Atypical left atrial flutter * Phrenic nerve palsy * Major Bleeding
1 secondary outcome
Powered Secondary Effectiveness Endpoint
Time frame: 3 years post index cardiac surgical procedure
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 7 Oct 2026.
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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.
37 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System in people with Post Operative Atrial Fibrillation and Atrial Fibrillation, Postoperative, run by AtriCure, Inc. at 37 sites in 2 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 2 inclusion and 20 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 7 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 37 sites in United States, Canada. 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 BoxX-NoAF Trial Inbox (1 (513) 755-4100, BoxXNoAF@atricure.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary Effectiveness Endpoint (time frame: 30 days post index cardiac surgical procedure). The study lists 2 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 7 Oct 2026.