Risk Factors for Acute Intraoperative Bradycardia in Patients Undergoing Gender-affirming Mastectomy

Purpose: Gender-affirming mastectomy surgery is highly desired within both transmasculine and nonbinary patient populations. The development of cardiac arrhythmias has been reported within this population. Acute intraoperative bradycardia in patients undergoing gender-affirming mastectomy has not been well described previously. This study aimed to describe the frequency of acute intraoperative relative bradycardia in patients undergoing gender-affirming mastectomies and identify potential risk factors that contribute to its occurrence. Methods: A retrospective review was performed for all patients who underwent gender-affirming mastectomy at a single institution. Data regarding patient demographics, comorbidities, and perioperative course were collected. Patients were separated into those who did and did not develop acute intraoperative bradycardia. The definition of relative intraoperative bradycardia was a heart rate below sixty beats per minute. Logistic regression was performed to determine which variables were predictive of bradycardia. Results: A total of 337 patients underwent gender-affirming mastectomy between January 2018 and January 2023. Of these patients, 144 (42.7%) experienced acute intraoperative relative bradycardia, with 97 (67.4%) requiring anesthetic intervention and 5 (3.5%) requiring halting or abortion of surgery. Two patients (1.4%) required compressions for asystole. Fluoxetine as an outpatient medication (OR: 2.63, P = .002) and harvest of a nipple graft (OR: 2.77, P = .018) were associated with a significantly increased risk of developing acute intraoperative bradycardia. Conclusion: Acute intraoperative relative bradycardia may be a unique phenomenon in patients undergoing gender-affirming mastectomies due to variables specific to this patient population. A future study comparing patients undergoing gender-affirming mastectomy to those undergoing elective breast surgeries is forthcoming to assess further risk factors.