Sex Differences in Individuals at High Risk of Atrial Fibrillation: A Primary Care Community Cohort Study, 2015–2024

Background: Sex differences in epidemiology and outcomes in atrial fibrillation (AF) are well documented, but their role in early detection and risk stratification in primary care remains unclear. Methods: This study used an observational, retrospective cohort design, including 9677 individuals identified as being at high risk (Quartile 4 of a validated prediction model) for developing atrial fibrillation, aged 65–95 years, and without prior AF or stroke in the Terres de l’Ebre health region (Catalonia, Spain). Incident AF and comorbidities prevalence were assessed from 1 January 2015 to 31 December 2024. Analyses compared sex-specific differences. Results: During follow-up, 3370 individuals (8.4%) developed AF, with higher incidence in men than women (9.9% vs. 7.0%, p < 0.001). In the high-risk subgroup (n = 9677), women had higher CHA2DS2-VA scores (4.10 vs. 3.84, p < 0.001) and greater prevalence of cognitive impairment (21.5% vs. 14.6%), while men more often presented with diabetes, ischemic cardiomyopathy, and peripheral vascular disease. Among new AF cases in this subgroup, men exhibited clustering of cardiometabolic conditions, whereas women showed higher cognitive decline. Conclusions: Distinct sex-specific patterns in comorbidity clustering and AF incidence were observed. These findings highlight the need for sex-tailored strategies for early AF detection and integrated risk management in primary care.