Isolation of Pulmonary Veins Using the Box Technique in Patients Undergoing Sternotomy (BoxTer)

June 23, 2026 updated by: Nantes University Hospital

BoxTer : Isolation of Pulmonary Veins Using the Box Technique in Patients Undergoing Sternotomy

Atrial Fibrillation (AF) is the most common cardiac arrhythmia worldwide, affecting approximately 2.8% of the population, with prevalence increasing with age. AF is associated with significant morbidity and mortality, accounting for about 25% of ischemic strokes, 10% of cryptogenic strokes, and a 10-40% annual increase in hospital admissions due to heart failure or anticoagulant-related events.

About 10% of patients undergoing cardiac surgery have preoperative AF. In 1986, Dr. Cox introduced the MAZE procedure, a surgical technique to isolate AF triggers. Initially involving atrial incisions, it evolved to use radiofrequency lines, significantly reducing morbidity and mortality. The MAZE procedure is now strongly recommended (Class Ia evidence) for concomitant cardiac surgery. However, nearly 85% of eligible patients-especially those undergoing closed-chest cardiac surgery-do not receive this treatment due to technical challenges and limited reproducibility of the Cox-Maze IV technique.

Pulmonary Vein Isolation (PVI) with posterior wall isolation (PWI-Box) has emerged as an effective alternative, offering similar outcomes to Cox-Maze IV with fewer adverse effects. Innovative devices like the GeminiS (Medtronic) enable minimally invasive, thoracoscopic PVI-PWI-Box procedures without opening the heart, even off-pump. This approach could expand the use of AF ablation during combined sternotomy surgeries, aligning with clinical guidelines.

Primary Objective: Assess the efficacy of PWI-Box using GeminiS combined with other cardiac surgeries via sternotomy.

Primary Endpoint: Recurrence rate of paroxysmal or persistent AF (per ESC definition) at 1 year postoperatively, confirmed by 24-hour Holter monitoring.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

200

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Patients with a surgical indication for AF in combination with conventional cardiac surgery performed by sternotomy (coronary artery bypass grafting, aortic valve replacement, aortic surgery, etc.). Patients may be included prospectively, via information provided by the attending physician during a consultation (written and oral), or retrospectively for those who have already undergone surgery, by sending an information notice with a non-objection period.

Description

Inclusion criteria:

  • Patients undergoing cardiac surgery via sternotomy
  • Concomitant use of the PWI box with GeminiS during surgery
  • Adult patients
  • Patients with the following characteristics: Preoperative paroxysmal/persistent/permanent AF; Duration of less than 5 years; And left atrium volume <60 ml/m2
  • Informed patient who did not object to the collection of their data for the study

Exclusion criteria:

  • Unplanned surgery (emergency)
  • History of cardiac surgery (reoperation)
  • Pregnant or breastfeeding women
  • Adults under guardianship, curatorship or judicial protection
  • Patients with a life expectancy of less than three years
  • Patients currently taking medication or using an experimental device that clinically interferes with the study's evaluation criteria and results.
  • Inability to comply with the monitoring schedule.
  • Contraindication to long-term anticoagulants

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
BOXTER Study population
Patients with a surgical indication for AF in combination with conventional cardiac surgery performed by sternotomy (coronary artery bypass grafting, aortic valve replacement, aortic surgery, etc.).
Other: Collection of study data from patient records
Collection of study data from patient records in the EPICARD national database at the time of surgery, 1 month post-surgery, 12 months post-surgery, 24 months post-surgery and 36 months post-surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Evaluate the efficacy of the PWI box, using GeminiS in combination with other cardiac surgery procedures via sternotomy, at 1 year post-operatively using 24-hour Holter monitoring.
Time Frame: 12 months
12 months

Secondary Outcome Measures

Outcome Measure
Time Frame
Evaluation of the efficacy of the PWI box using GeminiS in combination with other cardiac surgery procedures via sternotomy at 2 years postoperatively.
Time Frame: 24 months
24 months
Evaluation of the efficacy of the PWI box using GeminiS in combination with other cardiac surgery procedures via sternotomy at 3 years postoperatively.
Time Frame: 36 months
36 months
Evaluation of the rate of secondary endocardial ablation of AF.
Time Frame: 12 months
12 months
Evaluation of clinicals predictive factors for recurrence of AF after MAZE.
Time Frame: 36 months
36 months
Evaluate the rate of patients on anticoagulant and/or antiarrhythmic therapy after MAZE surgery.
Time Frame: 36 months
36 months
Assessment of complication rates associated with the technique used during cardiac surgery.
Time Frame: 36 months
36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nantes University Hospital

Investigators

  • Study Director: Charles-Henri DAVID, Nantes University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 5, 2026

Primary Completion (Estimated)

October 5, 2030

Study Completion (Estimated)

October 5, 2032

Study Registration Dates

First Submitted

December 16, 2025

First Submitted That Met QC Criteria

December 16, 2025

First Posted (Actual)

December 31, 2025

Study Record Updates

Last Update Posted (Actual)

June 24, 2026

Last Update Submitted That Met QC Criteria

June 23, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RC25_0420

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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