ABSTRACT NUMBER: ESOC2026A257 THE PREVALENCE OF COVERT CEREBRAL SMALL VESSEL DISEASE IN PEOPLE WITH ATRIAL FIBRILLATION AND LOW-TO-INTERMEDIATE STROKE RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background and aims To determine the prevalence of covert cerebral small vessel disease (CSVD) in people with atrial fibrillation (AF) and low-to-intermediate stroke risk. Methods We systematically reviewed the evidence by searching MEDLINE/Embase/Cochrane Library until May 2025. Observational or interventional studies reporting silent brain infarction (SBI) (including lacune), white matter hyperintensity/hypoattenuation (WMH), or cerebral microbleed (CMB) in people with AF and stratified by different stroke risk levels (defined by conventional risk assessment scores, e.g., the CHA2DS2-VASc score) were included for data extraction. Summary prevalence (95% confidence intervals [CIs]) of individual CSVD subtypes in people with AF and low-to-intermediate stroke risk were obtained using random-effects meta-analysis. The prevalence was also compared with those at high stroke risk. Results We included 7 observational studies (2956 participants). The prevalence of SBI was 28% (95% CI 16%-42%; 7 studies, N=2956, I2=94.78%) among people with AF and low-to-intermediate risk of stroke, 6% (95% CI 0%-19%; 5 studies, N=2585, I2=76.77%) with AF and low risk, and 25% (95% CI 14%-38%; 5 studies, N=2585, I2=84.43%) with AF and intermediate risk. There was comparable risk between low-to-intermediate and high risk groups (p=0.196). No eligible study analysed the prevalence of WMH and only 2 eligible studies (N=681) of CMBs showed a prevalence of 18% (95% CI 11%-26%) low-to-intermediate, 8% (95% CI 0%-21%) low, and 23% (95% CI 13%-34%) intermediate stroke risk among people with AF. Conclusions CSVD, particularly SBI, is common in people with AF and low-to-intermediate stroke risk, especially those at intermediate stroke risk. Conflict of interest A.A.: nothing to disclose; C.A.: nothing to disclose; M.H.: nothing to disclose; J.Y.: nothing to disclose: Z.Z.: reports holding the New South Wales (NSW) Cardiovascular Elite Postdoctoral Researcher Grant (H23/15813) from NSW Health that supports this study.