Reduced retinal microvascular density in women with coronary microvascular dysfunction: A pilot study

Objective

To compare retinal microvascular density among women with ischemia with no obstructive coronary artery disease (INOCA) with and without coronary microvascular dysfunction (CMD).

Design

Cross-sectional study.

Setting

Patients with myocardial INOCA often have CMD, possibly indicating systemic vascular dysfunction. While retinal microvasculature relates to many cardiovascular risk factors, its link with CMD remains unknown.

Participants

Women with INOCA (N = 18) and coronary function testing were enrolled and classified into CMD and non-CMD groups, with CMD defined as coronary flow reserve (CFR) <2.5 in response to adenosine.

Interventions

Participants underwent retinal optical coherence tomography angiography for noninvasive imaging of the retinal microvasculature.

Main outcome measures

Vessel density, perfusion density, and area, perimeter, and circularity of the foveal avascular zone (FAZ). Non-parametric statistics were used for comparisons.

Results

Mean age was 54.7 (SD 12.5) years. The CMD (N = 11) and non-CMD (N = 7) groups were balanced with respect to age, BMI, systemic diseases including diabetes, hypertension, and hyperlipidemia, and medications. Those with CMD had a lower retinal vessel density [20.9 (0.7) vs 21.6(0.8), p = 0.006] and lower inner perfusion density [38.5 (1.6) vs 41.2 (0.8), p = 0.006] as compared to those without CMD. There were no differences in the FAZ area, perimeter, or circularity.

Conclusions

In this study of women with INOCA, those with CMD showed lower retinal microvascular and perfusion densities than those without CMD. Direct, non-invasive retinal imaging is feasible, affordable, and may reflect coronary microvascular function in INOCA patients. A larger study, including men, is needed to confirm these findings.