Retinal Vascular Geometry and the Prevalence of Atrial Fibrillation and Heart Failure in a Clinic-Based Sample

Background We aimed to examine the cross-sectional association between a range of retinal vascular geometric variables and the prevalence of atrial fibrillation (AF) and heart failure. Methods The Australian Heart Eye Study (AHES) surveyed 1,680 participants presenting to a tertiary referral hospital for the evaluation of potential coronary artery disease by coronary angiography. Retinal vascular geometric variables (tortuosity, branching, and fractal dimension) were measured from retinal photographs using a computer-assisted program (Singapore I Vessel Assessment). Atrial fibrillation was determined based on a combination of self-reported history of AF; self-reported use of rate-control and anti-arrhythmic medications; and/or screening electrocardiogram. Self-reported echocardiography-confirmed heart failure was also documented. Results A total of 1,169 participants had complete information on retinal vascular geometric variables and AF and of these 104(8.9%) had AF. Participants in the second tertile of fractal dimension (D-f) compared to those in the highest tertile (reference group), had 92% increased likelihood of having AF after multivariable adjustment. A threshold effect for D-f was identified, and participants below versus those above a D-f threshold value of 1.472, had greater odds of having AF: multivariable-adjusted OR 1.85(95% CI 1.03-3.31). Measures of retinal tortuosity and branching were not associated with AR Retinal vascular geometric variables were also not associated with prevalence of heart failure. Conclusions A sparser retinal microvascular network (lower D-f) was independently associated with greater likelihood of AF. Further studies are needed to investigate whether temporal changes to the retinal vascular geometry are predictive of AF in the longer term.