Surgical Ablation of AF Efficacy Trial

Atrial fibrillation (AF) affects more than 1% of the general population and is an important risk factor for stroke. AF prevalence increases with age, occurring in 10 to 15% of patients older than 80 years of age, which is important with the aging population. Of patients undergoing cardiac surgery, 10.8% have a history of AF. AF is believed to cause the left atrium to dilate and lose its transport function. AF significantly increases the risk of ischemic stroke of cardioembolic origin, but is also associated with heart failure and impairs quality of life. Although the causal relationship between the 2 clinical entities has not been fully elucidated, AF is believed to cause heart failure via several mechanisms.

Ablation of AF is the application of scars to the atrial tissue to disrupt faulty electrical signals that cause the arrhythmia. If surgical ablation of AF yields a benefit similar to catheter-based AF ablation, thousands of people undergoing cardiac surgery could benefit from this procedure each year. SAFE will be a landmark trial in cardiac surgery, definitely establishing surgical AF ablation's impact on cardiovascular outcomes. Cardiac surgery is the optimal setting to establish whether maintenance of sinus rhythm through AF ablation yields clinical benefit, and is a setting where sham-control is possible. This will not only provide evidence for the cardiac surgical patients but will bolster the evidence for ablation (catheter or stand-alone surgical) in other AF patients.

The intervention under investigation is concomitant surgical AF ablation which is compared to no surgical AF ablation. The primary outcome is hospital readmissions with heart failure during 4 years of follow-up. This study will enroll 2000 patients from 50 centres, globally. Patients will be followed at hospital discharge, 4 to 6 weeks after surgery, 6 months after surgery, and then at 6-month intervals until the final follow-up visit, for a median follow-up for 4 years.

Inclusion criteria

• Age ≥ 18 years;
• Undergoing a clinically indicated cardiac surgical procedure: CABG, AVR, ascending aorta replacement, or combinations thereof;
• Documented history of paroxysmal or persistent AF
• Provide informed consent

Exclusion criteria

• Dominant atrial arrhythmia is atrial flutter;
• Documented left atrial diameter ≥ 6 cm;
• Previous cardiac surgery requiring opening of the pericardium;
• Patients undergoing any of the following procedures:

• Heart transplant
• Complex congenital heart surgery
• Sole indication for surgery is ventricular assist device insertion
• Mitral valve repair or replacement
• Tricuspid valve repair or replacement
• Patient resides in a long-term care facility