The effect of the anticholinergic burden on mortality following elective cardiac surgery

Abstract

Objective: The cumulative effect of drugs with anticholinergic properties may pose a significant risk in the post-discharge period of patients who have undergone elective cardiac surgery. The aim of this study was to investigate the association between anticholinergic burden and 6-month postdischarge mortality in older cardiac surgery patients.

Methods: This study performed a retrospective longitudinal analysis of patients undergoing elective cardiac surgery at a tertiary care centre from January 2021 to January 2022. The Deyo-Charlson comorbidity index (D-CCI) was used to estimate the burden of comorbidities. The anticholinergic burden was assessed using the Anticholinergic Cognitive Burden scale (ACB) and Drug Burden Index (DBI) scale. All-cause postdischarge mortality was determined from electronic medical records.

Results: A total of 255 older adults who had undergone elective cardiac surgery and had been followed up for at least 6 months were included in this study. Approximately 12.5% (n = 32) of older patients died within 6 months of discharge. In multivariate Cox regression analysis, ACB (HR:1.31, 95%CI:1.10-1.56 p = 0.01) and DBI (HR:2.08, 95%CI:1.27-3.39 p = 0.01) showed significantly increased risk of 6-month postdischarge mortality after adjusting for several possible confounders (age, gender, D-CCl, and American Society of Anaesthesiologists (ASA) score). Overall event-free survival differed significantly between patients undergoing cardiac surgery based on anticholinergic burden according to the group-stratified ACB and DBI scales (χ²: 5.907, log-rank test, p = 0.015 and χ²: 15.389, log-rank test, p < 0.001 respectively).

Conclusion: The anticholinergic burden is associated with 6-month all-cause post-discharge mortality in older cardiac surgery patients. A deprescribing approach should be considered, especially for older adults in the perioperative period.

Trial registration: The trial was retrospectively registered at ClinicalTrials.gov. Identifier: NCT05312684 Registered on 5 April 2022.

Keywords: Anticholinergic burden; cardiac surgery; drug burden index; mortality; older adults.