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.