Optical coherence tomography angiography (OCTA) assessing microvascular and macrovascular health in healthy octogenarians

Subclinical cardiovascular abnormalities are recognized as primary risk factors for cardiovascular disease (CVD). Most studies explore microcirculation, while the associations of peripheral microvascular structures and abnormalities have been understudied. This study aimed to use OCTA to gauge the microvascular structure in the proximal nailfold and estimate cardiovascular health via echocardiography, arterial tonometry, and blood tests in samples of healthy octogenarians. We employ unsupervised machine learning methodologies, and vascular patterns are clustered to identify possible microcirculatory characteristics for assessing cardiovascular conditions. We conducted a cross-sectional analysis on 104 participants aged over 80 years to investigate the association between peripheral microvascular structures and subclinical cardiovascular changes. We extracted 12 vascular features from processed three-dimensional nailfold microvasculature obtained from optical coherence tomography angiography (OCTA). Subjects with different microvascular patterns were assigned to one of two clusters using hierarchical clustering analysis based on feature similarity. The cardiovascular parameters of the subjects between these two clusters were statistically compared. As a result, the cluster with denser, smaller, and less tortuous microvascular structure exhibits better cardiovascular conditions regarding resting heartbeats, systolic function, left ventricular sizes, and arterial stiffness. Our study highlights the potential of estimating cardiovascular health in the elderly from nailfold microvascular structure.