Remimazolam besylate versus propofol as sedative agents in cardiac surgery: A randomized noninferiority clinical trial.

Background: Remimazolam besylate, despite being widely used in various clinical settings, lacks evidence in cardiac anesthesia. This trial compared its efficacy with propofol in elective cardiac surgery.

Methods: A total of 320 adult patients undergoing elective cardiac surgery via cardiopulmonary bypass between December 2024 and March 2025 were randomized 1:1 to either propofol (1 mg/kg for induction and 1-1.5 mg/kg/h for maintenance) or remimazolam besylate (0.3 mg/kg for induction and 1 mg/kg/h for maintenance) groups. The primary outcome was the sedation success rate (ie, bispectral index 40-60 throughout surgery with predefined dosages and without rescue sedatives), with an absolute difference of 3% as a noninferiority margin. Secondary outcomes included time from drug administration to bispectral index <60 (minute) and bispectral index variation within 15 minutes after drug withdrawal. Application of vasoactive drugs during induction, time to extubation (hour), length of stay in intensive care unit (hour), and hospital (day) were recorded.

Results: Of 320 enrolled patients, all patients completed the trial and 318 patients were analyzed eventually. The sedation success rate of the whole surgery was significantly higher in the remimazolam besylate group (159; 99.4%) than in the propofol group (130; 82.3%) (absolute difference 17.1%, 95% confidence interval 11.6%-23.9%; P < .001). No significant differences in time from drug administration to bispectral index <60 (P = .119), bispectral index variation after drug withdrawal (P = .658), time to extubation (P = .824), and length of stay in intensive care unit (P = .898) and hospital (P = .294) were observed.

Conclusions: Remimazolam besylate is noninferior to propofol in terms of sedation efficacy during elective cardiac procedures.