Improvement of albuminuria after renal denervation

Objectives

The primary objective of this study was the effect of renal denervation (RDN) on elevated urinary albumin-to-creatinine ratio (UACR) in treatment-resistant hypertensive patients. In addition, patients were stratified according their UACR at baseline into micro- (30–300 mg/g, n = 37) and macroalbuminuria (≥ 300 mg/g, < 2200 mg/g, n = 22).

Background

Increased albuminuria indicates cardiovascular and renal damage in hypertension. RDN emerged as an innovative interventional approach to reduce blood pressure (BP) and may thus reduce albumin urinary excretion.

Methods

Fifty-nine treatment-resistant hypertensive patients with elevated UACR at baseline underwent catheter-based RDN using the Symplicity Flex™ catheter (Medtronic Inc., Santa Rosa, CA).

Results

In the whole and pre-specified subgroups both office and 24-h ambulatory BP were significantly reduced 6 months after RDN. In parallel, a significant reduction in UACR occurred in all patients (160 (65–496) versus 89 (29–319) mg/g creatinine, p < 0.001) and in both subgroups (microalbuminuria: 83 (49–153) versus 58 (17–113) mg/g creatinine, p = 0.001; macroalbuminuria: (536 (434–1483) versus 478 (109–1080) mg/g creatinine, p < 0.001). In accordance, the prevalence of micro- and macroalbuminuria decreased significantly. Regression analysis revealed a modest positive relationship between the decrease of UACR and the fall of systolic BP (β = 0.340, p = 0.039) independent of renal function. Renal function remained unchanged after RDN.

Conclusions

In summary, following RDN, the magnitude of albuminuria as well as the prevalence of micro- and macroalbuminuria decreased in treatment-resistant hypertensive patients. Since albuminuria is an independent renal and cardiovascular risk factor, our findings suggest a reduction of renal and cardiovascular risk in these patients.