BoxX-NoAF Clinical Trial
EnCompass Clamp and the AtriClip in Box Lesion and Left Atrial Appendage EXclusion Procedure for the Prevention of New Onset of Atrial Fibrillation
1 other identifier
interventional
960
2 countries
10
Brief 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. 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Oct 2025
Longer than P75 for not_applicable
10 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
May 12, 2025
CompletedFirst Posted
Study publicly available on registry
May 25, 2025
CompletedStudy Start
First participant enrolled
October 24, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
November 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
November 1, 2031
February 20, 2026
May 1, 2025
3 years
May 12, 2025
February 18, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Primary Effectiveness Endpoint
The occurrence of clinically relevant post operative AF (POAF)
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
30 days post index cardiac surgical procedure
Secondary Outcomes (1)
Powered Secondary Effectiveness Endpoint
3 years post index cardiac surgical procedure
Study Arms (2)
Treatment
EXPERIMENTALIndex cardiac surgery + Ablation + Left Atrial Appendage Exclusion with AtriClip
Control
NO INTERVENTIONIndex cardiac surgery only
Interventions
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
Eligibility Criteria
You may qualify if:
- Planned and clinically indicated for cardiac surgical procedure requiring cardiac bypass and opening of the pericardium
- Age ≥ 65 years and CHA2DS2-VASc ≥ 3
You may not qualify if:
- 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
- Presence of a permanent pacemaker
- Infiltrative cardiomyopathies (i.e. amyloidosis)
- 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
- +4 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- AtriCure, Inc.lead
Study Sites (10)
St. Bernards Medical Center
Jonesboro, Arkansas, 72401, United States
Morton Plant Hospital - BayCare Health System, Inc.
Clearwater, Florida, 33759, United States
St. Joseph's Hospital - BayCare Health System, Inc.
Clearwater, Florida, 33759, United States
Orlando Health, Inc.
Orlando, Florida, 32806, United States
Wellstar Health System
Marietta, Georgia, 30062, United States
Corewell Health
Grand Rapids, Michigan, 49503, United States
Mayo Clinic
Rochester, Minnesota, 55905, United States
New York Presbyterian Hospital/Columbia University Irving Medical Center
New York, New York, 10032, United States
Ascension Saint Thomas
Nashville, Tennessee, 37205, United States
Hamilton General Hospital
Hamilton, Ontario, L8L 2X2, Canada
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- TRIPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
May 12, 2025
First Posted
May 25, 2025
Study Start
October 24, 2025
Primary Completion (Estimated)
November 1, 2028
Study Completion (Estimated)
November 1, 2031
Last Updated
February 20, 2026
Record last verified: 2025-05