Burden of atherosclerosis, cardiovascular risk factors and atrial fibrillation in individuals with covert brain infarcts in late midlife: the Akershus Cardiac Examination 1950 Study.

backgroundCurrent expert consensus statements generally suggest cardiovascular risk assessment, including atrial fibrillation (AF) screening, on detection of covert brain infarctions (CBIs). However, evidence to guide management of CBI remains limited. In the absence of randomised clinical trials specifically targeting CBI populations, observational studies comparing individuals with and without CBI can provide insights into the prevalence and burden of cardiovascular risk factors.

objectivesWe aimed to compare the burden of atherosclerosis and cardiovascular risk factors in participants with CBI to those without, and to explore the yield of AF screening in individuals with CBI.

designA prospective population-based birth cohort study including men and women born in 1950 and resident in Akershus County, Norway.

settingThe two hospitals serving the population of Akershus county, Norway.

participantsParticipants included in the Akershus Cardiac Examination (ACE) 1950 study who also underwent a subsequent MRI examination were eligible for this study. OUTCOME MEASURES: Cardiovascular risk assessment was performed at study inclusion (2012-2015). Carotid ultrasound was used to quantify atherosclerosis through a carotid plaque score, and CHA₂DS₂-VA and Systematic COronary Risk Evaluation 2 (SCORE2) scores were calculated to estimate cardiovascular risk. Brain MRI was performed in a randomly selected, blood pressure-stratified subset of participants (2016-2024). CBI was defined as focal lesions consistent with ischaemia in the absence of clinical stroke. Participants with CBI were offered 72-hour ambulatory ECG monitoring for AF detection.

resultsMRI was performed in 414 of 3706 (11%) participants in the ACE 1950 Study. The mean age at the time of the MRI examination was 70.2±2.3 years, and 165 (41%) were women. CBI was identified in 54 participants (13%), of whom 45 (83%) completed 72-hour ambulatory ECG monitoring. There were no differences in mean carotid plaque score, SCORE2 or CHA₂DS₂-VA score between participants with CBI compared with those with normal MRI findings. AF was detected in one (2%) participant with CBI.

conclusionsIn this community-based cohort of individuals in late midlife, individuals with CBI did not have an increased cardiovascular risk compared with those without, as indicated by SCORE2, CHA₂DS₂-VA score, age-appropriate carotid plaque burden and a low prevalence of AF. TRIAL REGISTRATION NUMBER: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT01555411.