Prognostic significance of the wall to lumen ratio of retinal arterioles evaluated by adaptive optics in human hypertension

Objective: Structural alterations in the microcirculation may be considered an important mechanism of hypertension-mediated organ damage. An increased media to lumen ratio of subcutaneous small resistance arteries evaluated with locally invasive techniques (biopsies of subcutaneous fat, micromyography) may predict the subsequent development of cardiovascular events. However, it is not presently known whether structural alterations of retinal arterioles evaluated with a non-invasive approach (adaptive optics) may have a prognostic meaning. Design and method: Two-hundred and thirty-seven subjects were included in the present study. They were normotensive subjects (n = 65, 27,4%) and patients with essential hypertension (n = 163, 68,8%) or primary aldosteronism (n = 9, 3,8%). All subjects were submitted to a non-invasive evaluation or retinal arteriolar morphology (evaluation of the wall/lumen ratio: WLR) by adaptive optics. The subjects were re-evaluated after an average follow-up time of 5.5 years on order to assess the occurrence of death or cardio-cerebrovascular events. Results: Fifty-four total events occurred in the population enrolled, of which 29 were cardio-cerebrovascular event (ischemic or hemorragic stroke, atrial fibrillation, heart failure, coronary artery disease, peripheral artery disease, including aneurism requiring intervention, cardiac valvular disease) while the remaining were events or deaths for any cause, including neoplastic disease. The event-free survival was significantly less in those with a WLR above the median value of the population (0.28) according to Kaplan-Mayer survival curves and multivariate analysis (p < 0.001 by both the Mantel-Cox test and the Breslow test). Subjects with events had a WLR of retinal arterioles significantly greater than those without events. The evidence was confirmed after restricting the analysis to cardiovascular events, excluding events or deaths of neoplastic origin. The average follow-up time of our subjects was 4.6 ± 1.6 years for a total of 1090 patients-years. Patients with cardiovascular events were older and with more elevated levels of circulating glucose. Conclusions: Structural alterations of retinal arterioles evaluated by adaptive optics may predict cardio-cerebral events and total mortality.