Transcutaneous Regulation for Atrial Prevention in Postoperative Atrial Fibrillation Following OPCAB

Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass surgery and may be associated with prolonged hospitalization and adverse cardiovascular outcomes. Transcutaneous auricular vagus nerve stimulation (taVNS) is a noninvasive neuromodulation technique that delivers mild electrical stimulation to the ear and may help regulate autonomic and inflammatory responses. This randomized controlled trial will evaluate whether perioperative taVNS can reduce the incidence of POAF in adults undergoing elective off-pump coronary artery bypass grafting (OPCAB). Participants will be randomly assigned in a 1:1 ratio to receive either taVNS in addition to standard perioperative care or standard perioperative care alone. The primary outcome is the incidence of new-onset atrial fibrillation within 7 days after surgery. Secondary outcomes will include atrial fibrillation burden, inflammatory markers, heart rate variability, use of antiarrhythmic and anticoagulant medications, safety, length of hospital stay, and major adverse cardiovascular events during follow-up.

Inclusion Criteria: 1. Age 18 years or older. 2. Scheduled to undergo elective off-pump coronary artery bypass grafting (OPCAB) for coronary artery disease with multivessel coronary artery disease. 3. Sinus rhythm on the preoperative baseline electrocardiogram, with no history of atrial fibrillation or other clinically significant arrhythmias. 4. Able and willing to provide written informed consent and comply with the study intervention and follow-up procedures. 5. Expected postoperative hospital stay of at least 7 days to allow postoperative atrial fibrillation monitoring. Exclusion Criteria: 1. History of atrial fibrillation or other arrhythmias requiring antiarrhythmic therapy. 2. Emergency OPCAB surgery or intraoperative conversion to on-pump coronary artery bypass grafting. 3. Concomitant cardiac surgery, such as valve surgery, or hybrid cardiac procedures. 4. Vagus nerve-related disorders, epilepsy, active ear infection, or implanted electrical devices such as a pacemaker or implantable cardioverter-defibrillator. 5. Severe comorbidities, including severe renal dysfunction (estimated glomerular filtration rate \