Renal denervation improves capillary density in hypertensive patients.

Background: 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 (HMOD). We report data on capillary density six and twelve months after RDN.

Methods: Endovascular RDN was performed in 132 patients with uncontrolled hypertension confirmed by 24-hour ambulatory blood pressure (ABP). Office and 24-hour 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.

Results: 24-hour ABP was reduced from 151/88 mmHg to 143/84 mmHg (six months after RDN) and to 142/82 mmHg (12 months after RDN) (all p <0.001). Retinal capillary density was improved both six and twelve months after RDN, as evidenced by an increase in CapA (1691 ± 805 µm2 at baseline vs. 1853 ± 948 µm2 six months after RDN, p = 0.021 and 1967 ± 980 µm2 twelve months after RDN, p = 0.034, (p = 0.097 for change between six and twelve months)).

Conclusions: In patients with arterial hypertension, blood pressure reduction by RDN increased retinal capillary density both six and twelve months after the procedure.