Renal denervation increases capillary density in hypertensive patients

AIMS: Cardiovascular (CV) outcome data after endovascular renal denervation (RDN) are sparse. Capillary density determines total peripheral resistance and thus blood pressure. Microvascular changes of the retinal vessels are a marker of hypertension-mediated organ damage. We report data on capillary density 6 and 12 months after RDN. METHODS AND RESULTS: Endovascular RDN was performed in 132 patients with uncontrolled hypertension confirmed by 24-h ambulatory blood pressure (ABP). Office and 24-h ABP were measured at baseline and 6 and 12 months after RDN. In parallel, retinal capillary density was measured by scanning laser Doppler flowmetry (Heidelberg Retina Flowmeter, Heidelberg Engineering, Germany). This technique uses the retinal microvasculature as a mirror of the microvasculature in the systemic circulation. The 24-h ABP was reduced from 151/88 mmHg to 143/84 mmHg (6 months after RDN) and to 142/82 mmHg (12 months after RDN) (all P < 0.001). Retinal capillary density was improved both 6 and 12 months after RDN, as evidenced by an increase in CapA [1691 ± 805 µm2 at baseline vs. 1853 ± 948 µm2 6 months after RDN, P = 0.021 and 1967 ± 980 µm2 12 months after RDN, P = 0.034, (P = 0.097 for change between 6 and 12 months)]. CONCLUSION: In patients with arterial hypertension, blood pressure reduction by RDN increased retinal capillary density both 6 and 12 months after the procedure.