Retinal microvasculature impairments in patients with coronary artery disease: An optical coherence tomography angiography study

Novel 2D/3D vascular biomarkers reveal association between fundus changes and coronary heart disease

PURPOSE

To compare structural and vascular differences in the macular region of the retina using optical coherence tomography (OCT)/OCT angiography (OCTA) between coronary angiography (CAG)-confirmed coronary heart disease (CHD) patients and non-CHD individuals.

METHODS

The study included 340 eyes from 180 CHD patients and 136 eyes from 68 controls. Imaging was conducted using the AngioVue OCT device with a macula-centered 6 mm ∗ 6 mm field of view. Retinal thickness and 2D/3D vascular-related biomarkers were derived using existing retinal layer segmentation software, and our previously proposed 2D/3D vascular and 3D foveal avascular zone segmentation methods. Statistical analyses included t-tests, Mann-Whitney U tests, chi-square tests, and Pearson's correlation.

RESULTS

The CHD group exhibited significantly lower retinal nerve fiber layer (RNFL) thickness (r = -0.20, P < 0.001) in the inner inferior (I) region, based on macular region layer segmentation. For the 3D OCT images, as defined by the ETDRS grid, both the inner and outer retina layers in the outer superior (out-S) region were significantly thinner in the CHD group. The CHD group showed significantly lower overall 2D fractal dimension (FD) (1.72 ± 0.03 vs. 1.73 ± 0.02, P < 0.001) and vessel skeleton density (VSD) (26.61 ± 4.52 vs. 28.50 ± 3.40, P < 0.001) compared to the control group. The proposed 3D vascular density (VD) feature showed a significant difference between the groups (19.23 ± 5.67 vs. 20.69 ± 5.15, P = 0.048).

CONCLUSION

Thinning of retinal thickness and reduced vascular density are associated with CHD and may serve as valuable, cost-effective biomarkers for assessing coronary artery disease assessment.

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.

Coronary artery and retinal vascularization by optical coherence tomography angiography: are eyes the window to the heart?

PURPOSE

Coronary artery disease (CAD) is the leading cause of death in the United States and its assessment still relies on invasive diagnostic procedures requiring contrast, such as coronary angiography (CAG) or computed tomography angiography (CCTA). The retinal vasculature is the only microvascular site in the human body that can be assessed non-invasively, and it has been described as a promising method for predicting cardiovascular risk since the classification of hypertensive retinopathy in the 19th century. Unfortunately, most classifications still rely on qualitative findings, which exhibit high rates of interobserver and intraobserver variability. With advances in ophthalmology exams, particularly the advent of optical coherence tomography angiography (OCTA), the capability of quantitatively assessing retinal vasculature can enable a more reliable non-invasive exam that could aid in estimating cardiovascular risk and assessing coronary lesions. This review aims to provide an extensive overview of the available evidence establishing the correlation of retinal and choroidal microvascular damage observed in OCTA and parameters such as coronary stenosis grade, number of affected vessels and scores like Gensini and SYNTAX evaluated via CAG or CCTA.

METHODS

Review of the literature published until December 2024 on PubMed/MEDLINE, SCOPUS and EMBASE by searching "optical coherence tomography angiography" or "OCTA" AND "Coronary artery disease" or "Coronary heart disease".

RESULTS

Findings from sixteen studies suggest a potential correlation between vascular parameters in OCTA and results from coronary exams. Reductions in vessel density analysis of the retinal plexus, especially the superficial capillary plexus (SCP), could improve patient selection and diagnostic yield for more invasive diagnostic procedures, such as CAG and CCTA.

CONCLUSION

OCTA is a non-invasive technology that can provide visualization and quantification of retinal microvascular disfunction that may correlate with macrovascular disease, particularly in the coronary circulation. Longitudinal assessment of quantitative OCTA parameters may provide biomarkers for monitoring CAD patients over time.

Application of optical coherence tomography angiography to study retinal and choroidal vascular changes in patients with first-time coronary artery stenosis

OBJECTIVE

To study the changes in retinal and choroidal vessels in patients with coronary artery stenosis via optical coherence tomography angiography (OCTA).

METHODS

A total of 100 subjects were enrolled in this study and divided into two groups: the observation group consisted of 50 patients with angina who were first diagnosed with coronary artery stenosis, and the control group consisted of 50 healthy adults without angina symptoms. All of the subjects underwent OCTA to investigate changes in retinochoroidal vessel density in patients with a first diagnosis of coronary artery stenosis. The parameters included superficial capillary plexus density (SCD), deep capillary plexus density (DCD), retinal peripapillary capillary plexus density(RPD), the choroidal vascular index (CVI), and the macular foveal avascular zone(FAZ area, perimeter, acircularity index, FD-300 vessel density).

RESULTS

SCD and DCD in the coronary artery stenosis group were lower than those in the control group (P = 0.045 and P = 0.034, respectively), the CVI was lower than that in the control group (P = 0.029), the FAZ perimeter and acircularity index were greater than those in the control group (P = 0.003,P = 0.024). Logistic regression and ROC curve analysis revealed that FAZ perimeter was the most significant risk factor for predicting coronary artery stenosis (P = 0.005, AUC = 0.664), and the cut-off value for FAZ perimeter was 2.065 mm.

CONCLUSIONS

In patients with a first diagnosis of coronary artery stenosis, both retinal and choroidal blood flow are reduced. FAZ perimeter is a risk factor for predicting the occurrence of coronary artery stenosis.

The severity of coronary heart disease and the incidence of later diabetic retinopathy in diabetic population: A retrospective cohort study

OBJECTIVES

The coronary heart disease (CHD) can influence the development of several diseases. The presence of CHD is correlated to a higher incidence of concurrent diabetic retinopathy (DR) in previous study. Herein, we aim to analyze the relationship between the CHD severity and following DR with different severity.

METHODS

A retrospective cohort study was conducted with the usage of Taiwan National Health Insurance Research Database (NHIRD). The CHD patients with DM were categorized into those with medical treatments and those received percutaneous coronary intervention (PCI) management with a 1:1 ratio. The major outcome was the development of DR, diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) 6 months after the onset of CHD.

RESULTS

There was 7317, 316, and 386 episodes of DR, DME and PDR in the mild CHD groups and 8568, 411, and 508 events of DR, DME and PDR in the severe CHD groups, respectively. The severe CHD group showed a significantly higher incidence of DR (aHR: 1.063, 95% CI: 1.038-1.089, P = 0.0324), DME (aHR: 1.412, 95% CI: 1.252-1.594, P = 0.0092) and PDR (aHR: 1.314, 95% CI: 1.172-1.473, P = 0.0113) compared to the mild CHD group. The cumulative incidence of DR was significantly higher in the severe CHD group (P < 0.001). In the subgroup analysis, the association between CHD severity and DR was more prominent in the female population (P = 0.0224).

CONCLUSIONS

The severe CHD is associated with higher incidence of following DR, DME and PDR, while the incidence of DR in CHD is positively correlated to longer disease period.

Hallmarks of aging: middle-aging hypovascularity, tissue perfusion and nitric oxide perspective on healthspan

Aging is a complex process marked by various changes at both cellular and systemic levels, impacting the functioning and lifespan of organisms. Over time, researchers have pinpointed several significant hallmarks of aging that lead to the gradual deterioration of tissue function, regulation, and homeostasis associated with aging in humans. Despite this, the intricate interactions and cumulative effects of these hallmarks are still mostly uncharted territory. Understanding this complex web is a major challenge in Geroscience, yet it is crucial for developing effective strategies that promote healthy aging, reduce medical costs, and ensure the sustainability of health systems. Gaining insights in this area is essential for creating interventions that can slow the aging process, enhance healthspan, and decrease the likelihood of age-related diseases. The integration of knowledge from various fields concerning the middle-aging nitric oxide (NO)-mediated hypovascularity hypoxia hemodynamic hypothesis points to a systems-based approach to the biological hallmarks of aging. Key evidence suggests a systemic connection between the endocrine system (specifically sex hormones), endogenous NO deficiency, and the vascular system, which serves as a network of microvascular structures crucial for tissue perfusion functions at cellular level. These processes also involve oxidative stress and inflammation triggered by hypoxia.

Conjunctival microvascular alteration in patients with coronary artery disease assessed using optical coherence tomographic angiography

BACKGROUND

To quantify conjunctival microvascular characteristics obtained by optical coherence tomographic angiography (OCTA) and investigate their relationship with the presence and severity of coronary artery disease (CAD).

METHODS

This cross-sectional study included 103 consecutive CAD patients confirmed by coronary angiography and 125 non-CAD controls. The temporal conjunctivas along the limbus of each participant were scanned using OCTA. Quantification of conjunctival microvasculature was performed by AngioTool software. The severity of the disease was evaluated using SYNTAX and Gensini scores.

RESULTS

Compared to the controls, the CAD group exhibited significantly lower vessel area density (30.22 ± 3.34 vs. 26.70 ± 4.43 %, p < 0.001), lower vessel length density (6.39 ± 0.77 vs. 5.71 ± 0.89/m, p < 0.001), lower junction density (3.44 ± 0.56 vs. 3.05 ± 0.63/m, p < 0.001), and higher lacunarity (0.11 ± 0.03 vs. 0.14 ± 0.05, p < 0.001). Among all participants, lower vessel area density, lower vessel length density, lower junction density, and higher lacunarity were associated with greater odds of having CAD; the adjusted ORs (95 % confidence intervals) per one SD decrease were 2.71 (1.71, 4.29), 2.51(1.61, 3.90), 2.06 (1.39, 3.05), and 0.36 (0.23, 0.58), respectively. Among CAD patients, junction density was negatively associated with the Gensini score (r = -0.359, p = 0.037) and the Syntax score (r = -0.350, p = 0.042) in women but not in men (p > 0.05).

CONCLUSIONS

Conjunctival microvascular characteristics were significantly associated with the presence of CAD. Junction density significantly associated with the severity of CAD among women patients.

SS-OCTA assessment of fundus microvascular changes and their correlation with coronary lesion severity in severe coronary heart disease

This study aimed to quantify fundus microvascular alterations in patients requiring revascularization for coronary heart disease (CHD) using swept-source optical coherence tomography angiography (SS-OCTA) and to investigate the correlation between these alterations and the severity of coronary artery lesions. SS-OCTA was employed to assess the fundus neurovascular parameters of all participants, while the Gensini score was utilized to gauge the severity of coronary artery lesions in observation group. A total of 98 participants (49 CHD patients and 49 controls) were included. Analysis of the SS-OCTA parameters revealed that the vascular density (VD) of the superficial vascular plexus (SVP), the superficial vascular complex (SVC), the intermediate capillary plexus (ICP) in the parafoveal region, the mean ICP in the macula, deep capillary plexus (DCP) and deep vascular complex (DVC) in each macular region were significantly reduced in the observation group compared to the control group (P < 0.05). Multivariate logistic regression indicated that lower VD values in the SVP, SVC, ICP, DCP and DVC across macular regions were significantly associated with an increased likelihood of severe CHD (OR < 1, P < 0.05). ROC curve analysis revealed that the maximum area under the curve for overall DCP VD in the macula was 0.707, with a cutoff value of 19.64, sensitivity of 65.30%, and specificity of 73.50%. In CHD group, Pearson correlation analysis demonstrated a negative correlation between the Gensini score and mean DCP VD (r = - 0.491, P < 0.001). Retinal VD in patients requiring revascularization for CHD is significantly lower compared to healthy controls. SS-OCTA-based retinal microvascular damage assessment is a valuable tool for risk stratification and early intervention in CHD.

Quantitative analysis of three-dimensional choroidal changes in coronary artery disease patients with swept-source optical coherence tomography angiography

PURPOSE

To quantitatively analyze three-dimensional (3D) choroidal changes in coronary artery disease (CAD) patients with swept-source optical coherence tomography angiography (SS-OCTA) based on a scan area of 12×12mm.

METHODS

236 CAD patients and 78 controls were included after coronary angiography (CAG) evaluation in this prospective cross-sectional study. Choroidal and foveal avascular zone (FAZ) parameters were compared between the two groups. Choroidal morphological characteristics were also evaluated based on ETDRS quadrants. Receiver operating characteristics (ROC) curves were generated to determine the discriminative power of choroidal and FAZ parameters. Linear regression analysis was used to determine the relationships between Gensini score and choroidal parameters.

RESULTS

Choroidal thickness (CT), choroidal vascular volume/ area (CVV/a), and choroidal stromal volume/ area (CSV/a) were significantly reduced in CAD patients, while 2D vascular density decreased only in 1-6 mm, and no statistical difference in choroidal vascularity index (CVI) values was detected. The AUC values of choroidal parameters were greater in the inner-6 mm area than the outer-6 mm area, and good performance was found with a combination with FAZ parameters (AUC=0.77, P < 0.001). For morphological analysis, both groups showed the greatest values in superior quadrant and the lowest in nasal quadrant. After controlling for confounding factors, Gensini score was negatively associated with CT (β = -0.35, P = 0.003), CVV/a (β = -0.17, P = 0.004), and CSV/a (β = -0.18, P = 0.005).

CONCLUSION

The SS-OCTA provided excellent visualization and quantification of the choroid and showed decreased choroidal thickness and volume in CAD patients, but the morphological features were unchanged. The severity of coronary artery stenosis was independently associated with choroidal changes.

Optical coherence tomography angiography of the retina and choroid in systemic diseases

Optical coherence tomography angiography (OCTA) has transformed ocular vascular imaging, revealing microvascular changes linked to various systemic diseases. This review explores its applications in diabetes, hypertension, cardiovascular diseases, and neurodegenerative diseases. While OCTA provides a valuable window into the body's microvasculature, interpreting the findings can be complex. Additionally, challenges exist due to the relative non-specificity of its findings where changes observed in OCTA might not be unique to a specific disease, variations between OCTA machines, the lack of a standardized normative database for comparison, and potential image artifacts. Despite these limitations, OCTA holds immense potential for the future. The review highlights promising advancements like quantitative analysis of OCTA images, integration of artificial intelligence for faster and more accurate interpretation, and multi-modal imaging combining OCTA with other techniques for a more comprehensive characterization of the ocular vasculature. Furthermore, OCTA's potential future role in personalized medicine, enabling tailored treatment plans based on individual OCTA findings, community screening programs for early disease detection, and longitudinal studies tracking disease progression over time is also discussed. In conclusion, OCTA presents a significant opportunity to improve our understanding and management of systemic diseases. Addressing current limitations and pursuing these exciting future directions can solidify OCTA as an indispensable tool for diagnosis, monitoring disease progression, and potentially guiding treatment decisions across various systemic health conditions.

Optical coherence tomography angiography in cardiovascular disease

Endothelial dysfunction and microvascular remodeling underly the development and progression of a host of cardiovascular disease (CVD). However, current methods to assess coronary epicardial microvascular function are invasive, time-intensive, and costly. Optical coherence tomography angiography (OCTA) is an established technology within ophthalmology that provides a quick, noninvasive assessment of vascular structures within the retina. As a growing body of evidence reveals strong associations between the retinal changes on OCTA and the development and progression of CVD, OCTA may indeed be a surrogate test for end-organ dysfunction. OCTA has potential to enhance diagnostic performance, refine cardiovascular risk assessment, strengthen prognostication, and ultimately, improve patient care. We explore the current literature on OCTA in cardiovascular diseases to summarize the clinical utility of retinal OCTA imaging and discuss next-generation cardiovascular applications.

Severity Stratification of Coronary Artery Disease Using Novel Inner Ellipse-Based Foveal Avascular Zone Biomarkers

Purpose

Given the similarities between the retinal and coronary microvasculature, the retina holds promising potential to serve as a non-invasive screening tool for coronary artery disease (CAD). We aimed to develop novel inner ellipse-based metrics and discern whether foveal avascular zone (FAZ) alterations can serve as indicators for CAD presence and severity.

Methods

Patients admitted to the Department of Cardiology who underwent coronary angiography were included. This resulted in an inclusion of 212 patients, of which 73 had no CAD. During the same visit, 6 × 6-mm (nominal size) fovea-centered optical coherence tomography angiography images of both eyes were acquired. The Gensini score (GS) was utilized to quantify CAD severity. Six known FAZ shape metrics were assessed and three novel biomarkers based on the inner ellipse were defined: absolute inner ellipse difference, Hausdorff distance, and Chamfer distance.

Results

Eight out of nine metrics showed significant associations with the GS in the left eye. However, significant differences across three CAD severity groups were only demonstrated by the novel metrics. Utilizing the Chamfer distance, age, and sex, patients with and without CAD could be distinguished with an average area under the curve (AUC) of 0.89 (95% confidence interval [CI], 0.84-0.95). Moreover, three CAD severity groups could be discerned with a macro average AUC of 0.77 (95% CI, 0.72-0.84).

Conclusions

A comprehensive assessment of FAZ shape descriptors was performed, and a strong association with CAD was found. The inner ellipse-based biomarkers especially demonstrated high predictive abilities for CAD presence and severity.

The Degrees of Coronary Heart Disease and the Degrees of New-Onset Blepharitis: A Nationwide Cohort Study

In this study, we aimed to evaluate the association between the severity of coronary heart disease (CHD) and the subsequent severity of blepharitis. This retrospective population-based cohort study was conducted using the National Health Insurance Research Database (NHIRD) of Taiwan. The participants with a CHD diagnosis were divided into mild CHD and severe CHD groups at a 1:2 ratio, according to whether percutaneous coronary intervention (PCI) was performed. The main outcomes were the development of blepharitis and severe blepharitis with the application of antibiotics. Cox proportional hazard regression was performed to obtain the adjusted hazard ratio (aHR) for blepharitis, with a 95% confidence interval (CI) between the groups. There were 22,161 and 15,369 blepharitis events plus 9597 and 4500 severe blepharitis episodes in the mild and severe CHD groups, respectively. The severe CHD group showed a significantly higher incidence of blepharitis development (aHR, 1.275; 95% CI: 1.051-1.912, p = 0.0285), whereas the incidence of severe blepharitis was not significantly different between the groups (aHR, 0.981; 95% CI: 0.945-1.020, p = 0.3453). The cumulative probability of blepharitis was significantly higher in the severe CHD group than in the mild CHD group (p < 0.001). In the subgroup analyses, the correlation between severe CHD and blepharitis was more significant in patients older than 70 years compared to the younger group (p = 0.0115). In conclusion, severe CHD is associated with a higher incidence of blepharitis than mild CHD, and this correlation is more prominent in individuals older than 70 years.

The impact of serum BNP on retinal perfusion assessed by an AI-based denoising optical coherence tomography angiography in CHD patients

Background

To investigate the correlation between retinal vessel density (VD) parameters with serum B-type natriuretic peptide (BNP) in patients with coronary heart disease (CHD) using novel optical coherence tomography angiography (OCTA) denoising images based on artificial intelligence (AI).

Methods

OCTA images of the optic nerve and macular area were obtained using a Canon-HS100 OCT device in 176 patients with CHD. Baseline information and blood test results were recorded.

Results

Retinal VD parameters of the macular and optic nerves on OCTA were significantly decreased in patients with CHD after denoising. Retinal VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary (RPC) was strongly correlated with serum BNP levels in patients with CHD. Significant differences were noted in retinal thickness and retinal VD (SCP, DCP and RPC) between the increased BNP and normal BNP groups in patients with CHD.

Conclusion

Deep learning denoising can remove background noise and smooth rough vessel surfaces. SCP,DCP and RPC may be potential clinical markers of cardiac function in patients with CHD. Denoising shows great potential for improving the sensitivity of OCTA images as a biomarker for CHD progression.

Ocular microvascular alteration in patients with myocardial infarction-a new OCTA study

Myocardial infarction is defined as a sudden decrease or interruption in blood flow to the coronary arteries, causing ischemic necrosis of the corresponding cardiomyocytes. It is unclear whether systemic macrovascular alterations are associated with retinal microvascular changes. This study utilized optical coherence tomography angiography (OCTA) to compare variations in conjunctival vascular density and fundus retinal vessel density between patients with myocardial infarction (MI) and healthy controls. This study recruited 16 patients (32 eyes) with MI and 16 healthy controls (32 eyes). The superficial retinal layer (SRL), deep retinal layer (DRL) and conjunctival capillary plexus in each eye were evaluated by OCTA. Parameters measured included the density of the temporal conjunctival capillary, retinal microvascular (MIR) and macrovascular (MAR) alterations and total MIR (TMI). The microvascular density of each retinal region was evaluated by the hemisphere segmentation (SR, SL, IL, and IR), annular partition (C1, C2, C3, C4, C5 and C6), and modified early treatment of diabetic retinopathy study (R, S, L, and I) methods. In the macular area, the superficial and deep retinal microvascular densities displayed notable variations. In the superficial layers, the superficial TMI, superficial MIR, and superficial MAR, as well as densities in the SL, IL, S, L, C1, C2, C5 and C6 regions, were significantly lower in MI patients (p < 0.05 each). In the deep layers, the deep MIR and deep TMI), as well as densities in the SL, IL, L, C1, C2 and C6 regions were significantly lower in MI patients (p < 0.05 each). In contrast, the conjunctival microvascular density was significantly higher in MI patients than in healthy controls (p < 0.001). The microvascular densities measured in the deep and superficial retinal layers and in the conjunctiva differ in MI patients and healthy controls. OCTA is effective in detecting changes in the ocular microcirculation.

Optical Coherence Tomography Angiography Changes in Patients Diagnosed With Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

We conducted a systematic review and meta-analysis to assess the association between optical coherence tomography angiography (OCTA) parameters and acute coronary syndrome (ACS). Two independent reviewers searched the electronic databases (MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Embase (Excerpta Medica Database), Cochrane Library, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform) from inception until April 2023. According to the inclusion criteria of this review, eligible were observational studies, randomized control trials, and registry/database studies that included the eyes of adult ACS patients and assessed OCTA parameters within the macula. The pooled standardized mean differences (SMD) between patients diagnosed with ACS and healthy controls with a confidence interval (CI) of 95% were calculated using the Hartung-Knapp-Sidik-Jonkman random-effects method. The heterogeneity was assessed by I2 and the Cochran Q and a random effects model was applied. Seven studies were eligible and included in our systematic review (n = 898), of which three were included in the meta-analysis (n = 341). The pooled SMD in the superficial vascular plexus (SVP), deep vascular plexus (DVP), and foveal avascular zone (FAZ) were -0.46 (95% CI: -0.94 to 0.01, p = 0.05, I2 = 0%, three studies), -0.10 (95% CI: -3.20 to 3.00, p = 0.75, I2 = 67%, two studies), and 0.43 (95% CI: -1.22 to 2.09, p = 0.38, I2 = 92%, three studies), respectively. Our findings suggest that there are no differences in OCTA metrics between ACS patients and healthy individuals.

Association of preoperative retinal microcirculation and perioperative outcomes in patients undergoing congenital cardiac surgery

BACKGROUND

Microcirculatory dysfunction is associated with increased morbidity and mortality in cardiac surgery patients. This study aimed to investigate the association between preoperative retinal microcirculation evaluated using optical coherence tomography angiography (OCTA) and perioperative outcomes in patients with congenital heart disease (CHD).

METHODS

This prospective, observational study was performed from May 2017 to January 2021. OCTA was used to automatically quantify the vessel density (VD) of the superficial capillary plexus, deep capillary plexus (DCP), and radial peripapillary capillary (RPC) preoperatively. The primary outcome was excessive postoperative bleeding, defined as bleeding volume > 75th percentile for 24-hour postoperative chest tube output. The secondary outcome was composite adverse outcomes, including one or more operative mortalities, early postoperative complications, and prolonged length of stay. The association between retinal VD and outcomes was assessed using Poisson regression.

RESULTS

In total, 173 CHD patients who underwent cardiac surgery were included (mean age, 26 years). Among them, 43 (24.9%) and 46 (26.6%) developed excessive postoperative bleeding and composite adverse outcomes, respectively. A lower VD of DCP (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.08-1.43; P = 0.003) was independently associated with excessive postoperative bleeding, and a lower VD of RPC (OR, 1.97; 95% CI, 1.08-3.57; P = 0.027), and DCP (OR, 2.17; 95% CI, 1.08-4.37; P = 0.029) were independently associated with the postoperative composite adverse outcomes.

CONCLUSION

Preoperative retinal hypoperfusion was independently associated with an increased risk of perioperative adverse outcomes in patients with CHD, suggesting that retinal microcirculation evaluation could provide valuable information about the outcomes of cardiac surgery, thereby aiding physicians in tailoring individualized treatment.

The association between cardiovascular risk profile and ocular microvascular changes in patients with non-ST elevation myocardial infarction

PURPOSE

We aimed to evaluate the association between ocular microvasculature (vascular density) on optical coherence tomography-angiography (OCT-A) and the cardiovascular risk profile of patients hospitalized for non-ST-elevation myocardial infarction (NSTEMI) patients.

METHODS

Patients admitted to the intensive care unit with the diagnosis of NSTEMI and undergoing coronary angiography were divided into 3 groups as low, intermediate, and high risk according to the SYNTAX score. OCT-A imaging was performed in all three groups. Right-left selective coronary angiography images of all patients were analyzed. The SYNTAX and TIMI risk scores of all patients were calculated.

RESULTS

This study included opthalmological examination of 114 NSTEMI patients. NSTEMI patients with high SYNTAX risk scores had significantly lower deep parafoveal vessel density (DPD) than patients with low-intermediate SYNTAX risk scores (p < 0.001). ROC curve analysis found that a DPD threshold below 51.65 % was moderately associated with high SYNTAX risk scores in patients with NSTEMI. In addition, NSTEMI patients with high TIMI risk scores had significantly lower DPD than patients with low-intermediate TIMI risk scores (p < 0.001).

CONCLUSIONS

OCT-A may be a non-invasive useful tool to assess the cardiovascular risk profile of NSTEMI patients with a high SYNTAX and TIMI score.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Retinal microvascular changes in patients with coronary artery disease and apnea

BACKGROUND

Optical coherence tomography angiography (OCT-A) allowed visualization of capillary level of retina; however, the relationship between coronary vascular status and retinal microvascular changes in patients with apnea is not known well. Our aim was to assess the retinal OCT-A parameters in patients with ischemia and angiographically proven microvascular disease and compare them with obstructive coronary disease in patients with apnea.

METHODS

Our observational study included 185 eyes of 185 patients, 123 eyes of patients with apnea (72 eyes from mild OSAS, 51 eyes from moderate to severe OSAS) and 62 eyes from healthy controls. Radial scans of the macula and OCT-A scans of the central macula (superficial (SCP) and deep (DCP) capillary plexuses) were performed on all participants. All participants had documented sleep apnea disorder within 2 years prior to coronary angiography. Patients were grouped by severity of apnea and coronary atherosclerosis (50 % stenosis cut-off value for obstructive coronary artery disease). Patients presented with myocardial ischemia and without coronary artery occlusion (<50 % diameter reduction or FFR > 0.80) constitute the microvascular coronary artery (INOCA) group.

RESULTS

Compared to healthy controls, patients with apnea showed deterioration in vascular density in all regions of the retina, regardless of obstructive or microvascular coronary artery disease on the ischemia background. This study has provided important observations of a high prevalence of INOCA in patients with OSAS and the presence of OSAS was a significant independent predictor of functional coronary artery disease. The relative decreases in vascular densities were more pronounced in the DCP layer according to SCP layer of macula. Only FAZ area values were significantly different according to the severity of OSAS (0.27 (0.11-0.62) and 0.23 (0.07-0.50) (p = 0.012)).

CONCLUSIONS

In patients with apnea, OCT-A can be used as a noninvasive tool to define coronary artery involvement, with similar retinal microvascular changes both in obstructive and microvascular coronary artery group. In patients with OSAS, we observed a high prevalence of microvascular coronary disease, supporting pathophysiological role of OSAS in ischemia of this group of patients.

Impaired retinal microcirculation in patients with non-obstructive coronary artery disease

PURPOSE

To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes.

METHODS

All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50 % in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50 % were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p < 0.017 is considered significant in multiple comparisons.

RESULTS

A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p = 0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p < 0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95 % CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95 % CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively.

CONCLUSION

Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.

Retinal and Choroidal Thinning—A Predictor of Coronary Artery Occlusion?

Introduction. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) allowed visualization of retina and choroid to nearly the capillary level; however, the relationship between systemic macrovascular status and retinal microvascular changes is not yet known well. Aim. Our purpose was to assess the impact of retinal optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) parameters on prediction of coronary heart disease (CHD) in acute myocardial infarction (MI) and chronic three vessel disease (3VD) groups. Methods. This observational study included 184 patients—26 in 3VD, 76 in MI and 82 in healthy participants groups. Radial scans of the macula and OCTA scans of the central macula (superficial (SCP) and deep (DCP) capillary plexuses) were performed on all participants. All participants underwent coronary angiography. Results. Patients in MI groups showed decreased parafoveal total retinal thickness as well as GCL+ retinal thickness. Outer circle total retinal thickness and GCL+ retinal thickness were lowest in the 3VD group. The MI group had thinner, while 3VD the thinnest, choroid. A decrease in choroidal thickness and vascular density could predict 3VD. Conclusions. A decrease in retinal and choroidal thickness as well as decreased vascular density in the central retinal region may predict coronary artery disease. OCT and OCTA could be a significant, safe, and noninvasive tool for the prediction of coronary artery disease.

Associations between Choriocapillaris Flow on Optical Coherence Tomography Angiography and Cardiovascular Risk Profiles of Patients with Acute Myocardial Infarction

We evaluated the association between macular perfusion assessed via optical coherence tomography angiography (OCTA) and the cardiovascular risk profiles of patients with acute myocardial infarction (AMI). Patients with AMI who underwent comprehensive ophthalmological examinations and retinal OCTA were evaluated retrospectively. Retinal OCTA was performed for each patient within 3 days of admission. Quantitative analyses of the vessel density (VD) of the superficial capillary plexus (SCP) layers, deep capillary plexus layers (DCP), and choriocapillaris were performed after image processing. The 10-year risk of atherosclerotic cardiovascular disease (ASCVD), Global Registry of Acute Coronary Events (GRACE) score, reduction of atherothrombosis for continued health (REACH) score, and thrombolysis in myocardial infarction (TIMI) risk score were assessed. Sixty patients were included. VD in SCP and DCP was not associated with a 10-year ASCVD risk; however, choriocapillaris flow void features were significantly correlated with the 10-year ASCVD risk: decreased count, increased average size, and increased signal void area were correlated with increased 10-year ASCVD risk, GRACE score, REACH score, and TIMI risk score. In the multivariate analysis, a 10-year ASCVD risk (adjusted odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01–1.08) and brain natriuretic peptide (adjusted OR, 1.00; 95% CI, 1.00–1.01) were significantly associated with the highest tertile of the average size of the choriocapillaris. Choriocapillaris flow void features measured using OCTA were associated with cardiovascular risk profiles in patients with AMI. OCTA may be used as an indicator of cardiovascular risk profiles and could improve cardiovascular risk assessments.

Detection of Systemic Diseases From Ocular Images Using Artificial Intelligence: A Systematic Review

PURPOSE

Despite the huge investment in health care, there is still a lack of precise and easily accessible screening systems. With proven associations to many systemic diseases, the eye could potentially provide a credible perspective as a novel screening tool. This systematic review aims to summarize the current applications of ocular image-based artificial intelligence on the detection of systemic diseases and suggest future trends for systemic disease screening.

METHODS

A systematic search was conducted on September 1, 2021, using 3 databases-PubMed, Google Scholar, and Web of Science library. Date restrictions were not imposed and search terms covering ocular images, systemic diseases, and artificial intelligence aspects were used.

RESULTS

Thirty-three papers were included in this systematic review. A spectrum of target diseases was observed, and this included but was not limited to cardio-cerebrovascular diseases, central nervous system diseases, renal dysfunctions, and hepatological diseases. Additionally, one- third of the papers included risk factor predictions for the respective systemic diseases.

CONCLUSIONS

Ocular image - based artificial intelligence possesses potential diagnostic power to screen various systemic diseases and has also demonstrated the ability to detect Alzheimer and chronic kidney diseases at early stages. Further research is needed to validate these models for real-world implementation.

Systemic retinal biomarkers

PURPOSE OF REVIEW

Systemic retinal biomarkers are biomarkers identified in the retina and related to evaluation and management of systemic disease. This review summarizes the background, categories and key findings from this body of research as well as potential applications to clinical care.

RECENT FINDINGS

Potential systemic retinal biomarkers for cardiovascular disease, kidney disease and neurodegenerative disease were identified using regression analysis as well as more sophisticated image processing techniques. Deep learning techniques were used in a number of studies predicting diseases including anaemia and chronic kidney disease. A virtual coronary artery calcium score performed well against other competing traditional models of event prediction.

SUMMARY

Systemic retinal biomarker research has progressed rapidly using regression studies with clearly identified biomarkers such as retinal microvascular patterns, as well as using deep learning models. Future systemic retinal biomarker research may be able to boost performance using larger data sets, the addition of meta-data and higher resolution image inputs.