Background
Recent studies have shown that anticholinergic medications are associated with cardiovascular disease. Little is known about how discontinuation of anticholinergic medication affects this association. We investigated how baseline anticholinergic load and change in anticholinergic load associates with major adverse cardiovascular events (MACE) on four different scales.

Methods
We included all geriatric outpatients aged 65 and older in Denmark between January 2011 and December 2018. Data were sourced from Danish national registries. Anticholinergic drug exposure was assessed at first contact to the outpatient clinic (baseline) and changes were assessed at 180 days after outpatient contact. Anticholinergic scales were the CRIDECO Anticholinergic Load Scale, Anticholinergic Drugs Scale, Anticholinergic Cognitive Burden and a scale by the Danish Institute of Rational Pharmacotherapy. Multivariate analyses were conducted to investigate the 1- and 5-year risk of MACE by baseline anticholinergic load and changes in anticholinergic load after 180 days.

Results
We included a total of 64 378 patients in the analysis of baseline anticholinergic load and 54 010 patients remained after 180 days for inclusion in the analysis of change in anticholinergic load. At baseline the mean age was 81.7 year (SD 7.5) and 68% were women. Higher level of anticholinergic load on any scale associated with greater risk of MACE in a dose response pattern. There were no association between reduction in anticholinergic load and risk of MACE.

Conclusion
While anticholinergic load at baseline was associated with MACE, reducing anticholinergic load did not lower the risk of MACE indicating the association may not be causal.