3.6 Central Pulse Pressure is an Independent Determinant of Vascular Remodelling in the Retinal Circulation

Objective Pulse pressure has been recognized as a risk factor for stroke. Moreover, it was shown that central pulse pressure (PP) relates more strongly to vascular disease and outcome than (peripheral) brachial PP. Hence, we analyzed the impact of central PP on retinal vascular structure, mirroring cerebral circulation. Design and methods The study cohort comprised 135 patients across a wide range of BP, but without evidence of diabetes. Parameters of retinal arteriole structure (wall-to-lumen (WLR) and function (change of retinal capillary flow (RCF) to nitric oxide synthase inhibitor N-monomethyl-L-arginine (L-NMMA), reflecting basal NO activity of the retinal vasculature) was assessed non-invasively and in vivo by scanning laser Doppler flowmetry. Central hemodynamics and augmentation index (AIx) were assessed by pulse wave analysis. Results WLR was correlated with central PP (r = 0.302, p < 0.001). In accordance, PP amplification (peripheral PP/central PP) was negatively correlated with WLR (r −0.223, p = 0.009). In contrast, MAP was not correlated with WLR (r = 0.110, p = 0.203). Moreover, AIx@75 correlated with WLR (r = 0.190, p = 0.028). The percent change of RCF to L-NMMA was correlated to WLR (r = 0.197, r = 0.022). Regression analysis revealed an independent relationship between WLR and both central PP (β = 0.277, p = 0.009) and percent change of RCF to L-NMMA (β = 0.170, p = 0.046). Conclusion Thus, central PP is an independent determinant of remodelling in small retinal arterioles indicating a coupling between the micro- and macrovascular changes to hypertension.