Remimazolam versus propofol on seizure adequacy in electroconvulsive therapy: a retrospective cohort study

Electroconvulsive therapy (ECT) is a core treatment modality for severe mental disorders, and the choice of anesthetic induction agent directly impacts seizure quality and therapeutic outcomes. This study aimed to compare the effects of remimazolam versus propofol on seizure adequacy during ECT.

This retrospective secondary analysis was conducted using data from a prospective observational cohort. A total of 859 ECT sessions from 114 patients were included. The primary outcome was the rate of adequate seizure, defined as an electroencephalographic (EEG) ictal duration of ≥15 seconds. Secondary outcomes included EEG seizure duration, post-ictal suppression index (PSI), maximum sustained power (MSP), and average seizure energy index (ASEI). Stabilized inverse probability of treatment weighting was employed to balance baseline covariates between groups, with balance assessed by standardized mean differences. Generalized linear mixed models were used to compare intergroup differences, accounting for random effects at the patient level. Subgroup analysis, E-value calculation, and propensity score matching (PSM) at 1:1 and 1:2 ratios were performed as sensitivity analyses to assess the robustness of the results.

A total of 859 ECT sessions were included, with 179 in the remimazolam group and 680 in the propofol group. Baseline characteristics were well-balanced between groups after weighting. The remimazolam group exhibited a significantly higher rate of adequate seizures compared with the propofol group (adjusted odds ratio: 12.054, 95% confidence interval: 5.758-25.233, P < 0.001), along with prolonged EEG seizure duration and elevated MSP. No significant between-group differences were observed in PSI or ASEI. The results of all sensitivity analyses were consistent with those of the primary analysis.

Remimazolam was associated with a higher rate of EEG seizure adequacy and longer EEG seizure duration; however, whether this electrophysiological advantage translates into better clinical outcomes remains to be investigated in prospective studies.