BackgroundCognitive improvement has been reported in patients receiving centrally acting angiotensin-converting enzyme inhibitors (C-ACEIs).AimsTo compare cognitive decline and survival after diagnosis of Alzheimer's disease between people receiving C-ACEIs, non-centrally acting angiotensin-converting enzyme inhibitors (NC-ACEIs), and neither.MethodRoutine Mini-Mental State Examination (MMSE) scores were extracted in 5260 patients receiving acetylcholinesterase inhibitors and analysed against C-/NC-ACEI exposure at the time of Alzheimer's disease diagnosis.ResultsIn the 9 months after Alzheimer's disease diagnosis, MMSE scores significantly increased by 0.72 and 0.19 points per year in patients on C-ACEIs and neither respectively, but deteriorated by 0.61 points per year in those on NC-ACEIs. There were no significant group differences in score trajectories from 9 to 36 months and no differences in survival.ConclusionsIn people with Alzheimer's disease receiving acetylcholinesterase inhibitors, those also taking C-ACEIs had stronger initial improvement in cognitive function, but there was no evidence of longer-lasting influence on dementia progression.