Retinal Arteriovenous Information Improves the Prediction Accuracy of Deep Learning-Based baPWV Index From Color Fundus Photographs.

Purpose: To compare the prediction accuracy of brachial-ankle pulse wave velocity (baPWV) from color fundus photographs (CFPs) using different deep learning models. Methods: This retrospective study analyzed the data of 696 participants whose baPWVs and CFPs were obtained during medical checkups. Arteriolar and venular probability maps, which were automatically calculated from the CFPs based on our modified deep U-net, Hokkaido University retinal vessel segmentation (HURVS) model, were applied as channel attention to retinal vessel location information to predict baPWV. The baPWV prediction parameters consisted of predicted baPWVs from a single-input model using CFPs only and from a three-input model using CFPs, and arteriolar and venular probability maps. The single- and three-input models adopted a common depth-wise net and were separately pretrained and trained with fivefold cross-validation. These baPWV prediction parameters were corrected using multiple regression equations with age, sex, and systolic blood pressure and were defined as single- and three-input regression-predicted baPWVs. The main outcome measures were the correlation coefficients between true baPWV and the baPWV prediction parameters. Results: The correlation coefficient with true baPWVs was higher for the three-input predicted baPWVs (R = 0.538) than for the single-input predicted baPWVs (R = 0.527). After regression, the three-input, regression-predicted baPWVs (R = 0.704) had the highest prediction accuracy, followed by the single-input, regression-predicted baPWVs (R = 0.692). Conclusions: The three-input model predicted true baPWVs with high accuracy. This improved prediction accuracy by channel attention to the arteriolar and venular probability maps based on the HURVS model confirmed that arterioles and venules are relevant regions for baPWV prediction.