Incident ischaemic heart disease in persons with Alzheimer's disease in a Finnish nationwide exposure-matched cohort

BackgroundPrevious studies on the association between cardiovascular diseases and Alzheimer's disease (AD) have been inconsistent despite the overlapping risk factor profile. We assessed whether the incidence of ischaemic heart disease (IHD) and revascularisation procedures are different in persons with AD than in the matched population without AD.MethodsWe conducted a nationwide exposure-matched cohort study including all 28,093 community-dwelling individuals with clinically verified diagnosis of AD, residing in Finland and alive on December 31, 2005. Participants were identified from the Special Reimbursement Register. One matched comparison person was identified for each participant with AD. We assessed the associations between AD and any IHD event (diagnosed IHD/revascularisation procedure), diagnosed IHD (myocardial infarctions and other IHD), and revascularisation procedure (angioplasty or bypass). Information on outcomes was extracted from the Hospital Discharge Register. Analyses were restricted to incident events during 2006–2009 and 25,325 AD-comparison person pairs were included in the analysis after excluding events occurring in 2002–2005.ResultsPeople with AD were more likely to have incident IHD diagnosis than AD-free comparison persons (adjusted HR, 95% CI 1.16, 1.06–1.28) but less likely to undergo revascularisation procedures (0.12, 0.08–0.20). There were no differences in all incident IHD events (0.95, 0.87–1.04).ConclusionsPersons with AD had a higher risk of incident ischaemic heart disease when comorbidities and cardiovascular medication were taken into account, but they were less likely to undergo revascularisation procedures. This was not entirely explained by contraindications. We acknowledge the need for more detailed studies assessing whether this reflects undertreatment of cardiac problems among persons with AD.