Achieving metrics during beating-heart ex-maze procedures improves outcomes

Area of Science:

• Cardiovascular Surgery
• Cardiac Electrophysiology
• Minimally Invasive Cardiac Procedures

Background:

• Current surgical treatments for atrial fibrillation (AF) lack intraoperative metrics to predict long-term outcomes.
• The extracardiac maze (Ex-Maze) procedure offers a beating-heart approach to AF treatment.
• Spontaneous conversion to sinus rhythm (SR) and pulmonary vein exit block are key predictors of AF freedom.

Purpose of the Study:

• To evaluate the efficacy of the beating-heart Ex-Maze procedure in patients undergoing concomitant cardiac surgery.
• To assess the correlation between intraoperative spontaneous rhythm conversion and pulmonary vein exit block with long-term AF freedom.

Main Methods:

• A beating-heart Ex-Maze procedure was performed in 54 AF patients undergoing various cardiac surgeries.
• A comprehensive, biatrial epicardial ablation pattern was created using unipolar, radiofrequency energy.
• Electrocardiogram and 24-hour Holter monitor data were collected intraoperatively and postoperatively up to 12 months.

Main Results:

• 32 of 48 patients (67%) spontaneously converted to SR during lesion creation.
• At a mean follow-up of 262 days, 88% of patients were free from AF, and 74% discontinued antiarrhythmic drugs.
• Pulmonary vein exit block was confirmed in 97% of tested patients, with 97% freedom from AF in this subgroup.

Conclusions:

• The Ex-Maze procedure enables creation of a comprehensive biatrial lesion pattern on a beating heart.
• Intraoperative observation of spontaneous conversion to SR and confirmed pulmonary vein exit block are crucial metrics for predicting successful long-term AF management.