Renal denervation increases capillary density in hypertensive patients

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.

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)].

In patients with arterial hypertension, blood pressure reduction by RDN increased retinal capillary density both 6 and 12 months after the procedure.