Association Of Retinal Microvascular Impairment With The Presence And The Degree Of Coronary Artery Disease

Background: Recently,the role of microvascular disease in coronary artery disease(CAD)has gradually gain attention.Previous studies have shown that microvascular damage does not present alone,but mostly coexists with obstructive CAD,and is significantly corelated with gradual deterioration of cardiac function and long-term cardiovascular adverse events.Therefore,screening for microvascular disease in CAD can provide additional diagnostic and prognostic significance.The current examination methods for coronary microvascular dysfunction are either invasive or quite expensive,which limits their wide application in clinical settings.Coronary microcirculation and retinal microvasculature have similar anatomical structures and blood vessel levels.They are exposed to the same internal environment.The morphological structure and physiological functions of retinal blood vessels are closely related to systemic vascular disease.Prior studies have discussed the relationship between changes in the structure and function of the retinal microvasculature and cardiovascular disease.However,in these studies,direct fundoscopy and color fundus photographs were mostly used to assess retinal vessels.These methods are subjective and may be interfered by many factors.Optical coherence tomography(OCTA),as a new non-invasive examination technology,can visualize the retinal microvascular system with high resolution,but its clinical application still needs further verification.In addition,in previous studies,researchers paid less attention to the severity of coronary obstructive lesions.The severity of coronary artery disease is directly related to the patient’s clinical symptoms,heart function and treatment decisions.Studies have suggested that microvascular disease may be a manifestation of early atherosclerosis and related to the progression of the disease.However,the association between retinal microvascular impairment and the severity of coronary obstructive lesions has not been established.Objectives: To determine the retinal microvascular impairment in CAD and its association with the severity of coronary obstructive lesions using optical coherence tomography angiography(OCTA).Methods: The cross-sectional study was conducted in Guangdong Provincial People’s Hospital,China.The study included patients with confirmed or suspected CAD who planned to undergo coronary angiography.Retinal microvascular parameters were measured by OCTA of the optic disc,including the vessel density and retinal nerve fibre thickness of the radial peripapillary capillary.In terms of the entire macula,vessel density of the superficial capillary plexus(SCP)and deep capillary plexus(DCP)were included.We compared the OCTA parameters between CAD group and control group.The SYNTAX score was used to evaluate the severity of coronary lesions in patients with confirmed obstructive coronary diseases.Receiver operating characteristic(ROC)curve analysis was used to evaluate the diagnostic value of retinal vessel density for the CAD.Multivariable regression analyses were performed to determine the association of retinal vessel density with the presence of CAD and SYNTAX score of coronary stenotic lesions.Results: A total of 241 participants,including 159 CAD patients(135 obstructive24 non-obstructive)and 82 controls,were included in the study.CAD patients with or without obstructive lesions,had significantly lower SCP and DCP vessel density than healthy control.Overall,participants showed significantly greater odds of having CAD in the lower versus higher vessel density for SCP,OR = 4.25(95% CI 2.27-7.98)and DCP,OR = 4.98(95% CI 2.70-9.21).ROC curve analysis showed that retinal vessel density of SCP and DCP had modest value in predicting CAD(AUC = 0.692 for SCP;AUC = 0.771 for DCP).Among obstructive CAD patients,vessel density of SCP and DCP were inversely corelated with SYNTAX scores(For SCP,R=0.570,P<0.001;For DCP,R=0.658,P<0.001).Vessel density of SCP and DCP were independent predictors for severe coronary disease(SCP: adjusted OR=4.22,95% CI 1.62-10.98,P=0.003;DCP: adjusted OR=6.26,95% CI 3.95-12.07,P<0.001).Conclusion: Patients with CAD has significantly lower SCP and DCP vessel density than healthy control.In patients with obstructive CAD,both SCP and DCP vessel density are independently associated with SYNTAX score.Retinal microvascular impairment based on OCTA study is helpful for the identification of CAD and the assessment of the severity of coronary obstructive lesions.