Purpose
Microvascular mechanisms are increasingly recognised as being involved in a significant proportion of coronary artery disease (CAD) cases, but the exact role and contribution is unclear. In the current study, we aimed to determine whether retinal microvascular structural changes are associated with severity of CAD as assessed by coronary angiography.
Methods
The Australian Heart Eye Study examined 1116 patients (mean age 60.9±11.4 years) presenting for evaluation of potential CAD by coronary angiography during 2009-12 at Westmead Hospital, Sydney, Australia. Retinal images were taken and retinal vessel caliber was quantified using validated computer-based methods. Routine diagnostic invasive angiography was performed 6 hours fasting. A vessel score was calculated based on the number of vessels with significant obstructive coronary disease. This definition was used for the left main coronary artery, right coronary, left anterior descending and left circumflex arteries. Scores ranged from 0 to 3, depending on the number of vessels with greater than 50% stenoses. Left main artery stenosis was scored as double vessel disease.
Results
After adjusting for age, sex, ethnicity, fellow vessel caliber, previous history of diabetes and acute myocardial infarction, participants with narrower retinal arteriolar caliber (i.e. comparing smallest versus largest arteriolar caliber quartile) were more likely to have stenoses ≥50% in any of the vessels, odds ratio, OR 1.54 (95% CI 1.02-2.33). Additionally, patients with narrower retinal arteriolar caliber were more likely to have 3 vessels with greater than 50% stenoses, OR 1.56 (95% CI 1.15-2.12) than those with wider arteriolar caliber, while patients with wider retinal venules (comparing largest versus smallest quartile) were more likely to have stenoses ≥50% in any of the vessels, OR 1.93 (95% CI 1.24-3.00) than those with narrower venular caliber.
Conclusions
Retinal arteriolar caliber narrowing and venular widening were associated with the severity of angiographically-documented coronary artery stenoses. These findings provide further understanding of the role of microvascular mechanisms in CAD and suggest retinal imaging may be a measure of subclinical CAD.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications