Atrial cardiomyopathy and MRI-detected covert brain infarction in an elderly population-based cohort: the Akershus Cardiac Examination 1950 study

Introduction Atrial fibrillation is associated with both clinical stroke and covert brain infarction (CBI). Atrial cardiomyopathy has been proposed in absence of atrial fibrillation as an independent stroke risk factor, but supporting evidence is limited. This study aimed to investigate the association between echocardiographic and biochemical markers of atrial cardiomyopathy and the presence of CBI on magnetic resonance imaging (MRI) in an elderly population-based cohort. Methods In the Akershus Cardiac Examination 1950 Study, transthoracic echocardiography and biobanking were performed at first visit (2012–2015). Markers of atrial cardiomyopathy included echocardiographic body surface area-indexed left atrial maximum and minimum volume, left atrial reservoir and contractile strain, and N-terminal pro B-type natriuretic peptide (NT-proBNP). Brain MRI was performed in a subset of participants (2016–2024), that were drawn according to participation in another study and stratified by blood pressure at age 40. Results Of 3706 participants, 414 (11%) underwent MRI and were included in this analysis. At the time of MRI, the mean age was 70.2 (± 2.3) years, and 167 (40.3%) were women. CBI was detected in 54 participants (13.0%), of whom only one (1.9%) had a history of clinical atrial fibrillation at study entry. After excluding 19 participants with known atrial fibrillation at the time of MRI, no significant differences in echocardiographic indices or NT-proBNP levels were observed between participants with and without CBI. Logistic regression analyses (unadjusted and adjusted) showed no associations between these markers and CBI. Conclusion In an elderly cohort from the general population, echocardiographic and biochemical markers of atrial cardiomyopathy were not associated with CBI in those without preexisting atrial fibrillation. Clinical trial registration ClinicalTrials.gov Identifier: NCT01555411.