Abstract Body (Do not enter title and authors here): Introduction: Patients with myocardial ischemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD), which may be a manifestation of systemic vascular dysfunction. The state of retinal microvasculature is linked to a variety of cardiovascular risk factors, but the relationship between CMD and the retinal microvasculature is unknown.
Research Question: Among individuals with INOCA, are retinal microvasculature changes reflective of CMD?
Aim: To evaluate the retinal microvasculature in women with INOCA, comparing those with and without CMD.
Methods: Women with INOCA (N=18) who had coronary function testing to evaluate for CMD were enrolled at Emory University between 2018-2021. Participants were classified into a CMD group and a non-CMD group, with CMD defined as coronary flow reserve (CFR) <2.5 in response to adenosine. Participants underwent retinal optical coherence tomography angiography to assess the retinal microvasculature. Vessel density, perfusion density, as well as perimeter and circularity of the foveal avascular zone (FAZ) were obtained. Non-parametric statistics were used to compare the two groups.
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, and presence of systemic diseases including diabetes, hypertension, and hyperlipidemia. Those with CMD had a lower inner retinal vessel density [22.6(1) vs 21.2(0.5), p=0.006], lower full vessel density [21.2(0.6) vs 19.9(0.8), p = 0.008], lower inner perfusion density [41.1(0.8) vs 38.5(2.1), p=0.006] and lower full perfusion density [38.5(0.6) vs 36.1(1.8), p=0.007]. There were no differences in the FAZ perimeter or circularity between the two groups.
Conclusions: In women with INOCA, those with CMD had a lower retinal microvascular density and perfusion density compared to non-CMD group. Direct, non-invasive, and relatively inexpensive imaging of the retinal microvasculature is feasible and may serve as a window to coronary microvascular function in women with INOCA; a larger study, including men, is needed to confirm these findings.