Effect of Intensive Blood Pressure Lowering Treatment on Retinal Microvasculature: Secondary Analysis From ESPRIT

Retinal microvasculature is a key affected target organ of hypertension, which can serve as a marker of systemic microcirculation. Whether intensive blood pressure-lowering treatment affects retinal microvasculature remains unknown.

The purpose of this study was to assess the effect of intensive treatment targeting systolic blood pressure <120 mm Hg on retinal microvasculature compared with standard treatment targeting systolic blood pressure <140 mm Hg.

In a multicenter randomized trial conducted at 116 sites in China, we randomly assigned adults aged 50 years or older with high cardiovascular risk to receive intensive treatment targeting systolic blood pressure <120 mm Hg or standard treatment targeting systolic blood pressure <140 mm Hg. A subgroup of participants at 17 sites was selected to undertake color fundus photography at a 3-year follow-up. Retinal microvasculature measures were derived via a standard pipeline. The main outcome was arteriole-venule ratio, a measure of retinal arteriolar caliber. Other measures of vessel complexity, density, and tortuosity were also compared. Subgroup analyses of sex, age, diabetes, coronary heart disease, stroke, systolic blood pressure level, hypertension duration, and pupil dilation status were performed for arteriole-venule ratio.

In total, 555 participants in the intensive arm and 526 in the standard arm were included. Mean age was 62.7 ± 6.4 years, and 37.8% were women. After adjusting for age and sex, the intensive arm showed increased arteriolar caliber, as evidenced by arteriole-venule ratio (β = 0.16; 95% CI: 0.05-0.28; P = 0.005) compared with the standard arm, consistent with central retinal arteriole equivalent (β = 0.14; 95% CI: 0.02-0.25; P = 0.02). No significant results were observed for venular caliber. No heterogeneity was found across subgroups. The intensive arm also showed increased arteriolar complexity, arteriolar density, and reduced vessel tortuosity compared with the standard arm.

Among hypertensive patients with high cardiovascular risk, lowering systolic blood pressure with a target of <120 mm Hg compared with <140 mm Hg has a favorable impact on retinal microvasculature, providing the first evidence that such intervention may improve systemic microcirculation and mitigate hypertension-mediated organ damage. (Effects of Intensive Systolic Blood Pressure Lowering Treatment in Reducing RIsk of Vascular evenTs [ESPRIT] Study; NCT04030234).