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

• Published in: Cardiovascular revascularization medicine Vol. 50; pp. 26 - 33
• Main Authors: Mailey, Jonathan A., Moore, Julie S., Brennan, Paul F., Jing, Min, Awuah, Agnes, Trucco, Emanuele, McLaughlin, James A.D., Nesbit, M. Andrew, Moore, Tara C.B., Spence, Mark S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2023
• Subjects: Blood Flow Velocity; Cardiovascular disease; Cardiovascular screening; Conjunctiva; Conjunctiva - blood supply; Coronary Angiography; Coronary artery disease; Coronary Artery Disease - diagnostic imaging; Coronary Vessels - diagnostic imaging; Cross-Sectional Studies; Humans; Microcirculation - physiology; Microvascular dysfunction; Prevention; Prevention; Microvascular dysfunction; Cardiovascular disease; Cardiovascular screening; Conjunctiva; Coronary artery disease
• ISSN: 1553-8389; 1878-0938
• DOI: 10.1016/j.carrev.2023.01.007

Atherosclerotic heart disease often remains asymptomatic until presentation with a major adverse cardiovascular event. Primary preventive therapies improve outcomes, but conventional screening often misattributes 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.
To compare conjunctival microcirculatory function in patients with and without obstructive coronary artery disease.
We compared the conjunctival microcirculation of myocardial infarction patients (MI-cohort) to controls 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 μm in diameter.
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 μm vessels (3268/3602 vessels) and was lower in the MI-cohort (134 ± 64 s−1 vs 140 ± 63 s−1, p = 0.002).
Conjunctival microcirculatory alterations can be observed in patients with obstructive coronary artery disease. The conjunctival microvasculature merits further evaluation in cardiovascular risk screening.
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•The conjunctival microvasculature can be assessed using a smartphone and slit-lamp biomicroscope•Abnormalities in microvascular function can be detected in the conjunctiva of patients with myocardial infarction•The detection of conjunctival microvascular dysfunction may have utility in cardiovascular risk assessment