Current 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.

We 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.

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

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

Participants included in the Akershus Cardiac Examination (ACE) 1950 study who also underwent a subsequent MRI examination were eligible for this study.

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.

MRI 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.

In 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.

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01555411.

To investigate whether seafarers in Norway who were declared unfit for service at sea or received a time-limited health certificate had a higher risk of acute somatic hospital admissions compared with those who received a full health certificate.

Registry-based cohort study.

Seafarers in Norway who presented to a seafarer’s doctor to obtain a health certificate between 2018 and 2019, as required for work aboard Norwegian vessels. The study was conducted within Norway’s publicly funded healthcare system.

Norwegian seafarers aged 18–70 years who underwent medical examinations (n=43 758), including n=5452 females (12.5%).

Acute somatic hospital admission within 2 years of medical examination. HRs were estimated using Cox regression models in two separate time periods (0–3 months and 3–24 months), with adjustment for possible confounding from age, gender, level of education and centrality of residence (proximity to healthcare services).

The crude risk of acute somatic hospital admissions was higher for individuals who received a declaration of unfitness, as compared with those who received a full health certificate, in both follow-up periods: 0–3 months (HR=5.13, 95% CI: 3.27 to 8.04) and 3–24 months (HR=2.63, 95% CI: 2.07 to 3.34). Similarly, those with time-limited health certificates had a higher risk in both periods: 0–3 months (HR=2.02, 95% CI: 1.39 to 2.93) and 3–24 months (HR=2.45, 95% CI: 2.15 to 2.79). Adjustment of the analyses for socio-demographic factors did not change the effect estimates substantially.

These findings highlight the importance of comprehensive and continuous health assessments to help prevent adverse health outcomes and ensure safety at sea, particularly among vulnerable subgroups of seafarers.