Assessment of Indices of Conjunctival Microvascular Function in Patients With and Without Obstructive Coronary Artery Disease

Background: Atherosclerotic heart disease often remains asymptomatic until presentation with a major adverse cardiovascular event. Primary preventive therapies improve outcomes, but conventional screening often misat-tributes risk. Vascular imaging can be utilised to detect atherosclerosis, but often involves ionising radiation. The conjunctiva is a readily accessible vascular network allowing non-invasive hemodynamic evaluation.Aim: To compare conjunctival microcirculatory function in patients with and without obstructive coronary artery disease.Methods: We compared the conjunctival microcirculation of myocardial infarction patients (MI-cohort) to con-trols with no obstructive coronary artery disease (NO-CAD cohort). Conjunctival imaging was performed using a smartphone and slit-lamp biomicroscope combination. Microvascular indices of axial (Va) and cross-sectional (Vcs) velocity; blood flow rate (Q); and wall shear rate (WSR) were compared in all conjunctival vessels between 5 and 45 mu m in diameter.Results: A total of 127 patients were recruited (66 MI vs 61 NO-CAD) and 3602 conjunctival vessels analysed (2414 MI vs 1188 NO-CAD). Mean Va, Vcs and Q were significantly lower in the MI vs NO-CAD cohort (Va 0.50 +/- 0.17 mm/s vs 0.55 +/- 0.15 mm/s, p < 0.001; Vcs 0.35 +/- 0.12 mm/s vs 0.38 +/- 0.10 mm/s, p < 0.001; Q 154 +/- 116 pl/s vs 198 +/- 130 pl/s, p < 0.001). To correct for differences in mean vessel diameter, WSR was compared in 10-36 mu m vessels (3268/3602 vessels) and was lower in the MI-cohort (134 +/- 64 s-1 vs 140 +/- 63 s-1, p = 0.002).Conclusions: Conjunctival microcirculatory alterations can be observed in patients with obstructive coronary ar-tery disease. The conjunctival microvasculature merits further evaluation in cardiovascular risk screening.(c) 2023 Elsevier Inc. All rights reserved.