An interventional study of Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System in Post Operative Atrial Fibrillation and Atrial Fibrillation, Postoperative, sponsored by AtriCure, Inc.. Recruiting at 37 sites in 2 countries. Open to participants aged 65 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-07.
Sponsored by AtriCure, Inc. · Not applicable, Interventional, and Prevention
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.
3,870 studies on the registry are indexed under Atrial Fibrillation; 924 are open to participants now.
This study's planned enrollment of 960 is above the median of 144 across 2,380 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →AtriCure, Inc. is the lead sponsor of 31 studies on the registry; 5 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 4 (80%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Index cardiac surgery + Ablation + Left Atrial Appendage Exclusion with AtriClip
Device: Isolator® Synergy™ EnCompass® Ablation System and AtriClip® LAA Exclusion System
Index cardiac surgery only
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
Primary Effectiveness Endpoint
The occurrence of clinically relevant post operative AF (POAF)
Time frame: 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
Time frame: 30 days post index cardiac surgical procedure
Powered Secondary Effectiveness Endpoint
The time to first occurrence of clinical atrial fibrillation from 30 days after index cardiac surgical procedure through 3-years
Time frame: 3 years post index cardiac surgical procedure
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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AtriCure, Inc.