NEPHROPROTECTIVE EFFECT OF RD ACCORDING TO 5-YEAR FOLLOW-UP

Abstract

Objective: To evaluate the nephroprotective effect of renal denervation (RD) in the form of anatomical and functional preservation of the kidneys in patients with resistant hypertension (RHT) over 5 years of follow-up. Design and method: The data of 23 patients with RHT (average age 57.6 ± 8.3 years) were analyzed. Initially and 6, 12, 24, 36 and 60 months after RD of observation, all patients were measured office and average 24-hour blood pressure (BP) monitoring, kidney function was assessed by serum creatinine and cystatin C levels and the calculation of glomerular filtration rate (eGFR). Non-contrast MRI of the kidneys (magnetic field strength 1.5 T) was performed at all observation points. RD was performed using a renal ablation electrode Symplicity Flex and an automated RF voltage generator Symplicity G2. Results: The average values of creatinine level corresponded to 80.2 ± 14.8 mmol/L, cystatin C – 684.8 ± 86.2 mg/l. According to MRI data, the volume of the right/left kidneys was 174 ± 41.6/ 194.9 ± 52.7 cm3, the cortical layer of the right/left kidneys was 62.7 ± 19.2/67.8 ± 26.1 cm3, respectively. 5 years after RD, there was a pronounced and significant decrease in the daily systolic BP/diastolic BP by -12.7/ -10.4 mmHg, respectively (p = 0.007), which confirms the effectiveness of RD. There was a statistically significant decrease in the volume of the cortex (right/left -24 cm3/21 cm3, p < 0.001), which was accompanied by a significant increase in creatinine ( 7 mmol/L, p = 0.0003) and cystatin C ( -298 mg/L, p = 0.0003), as well as a decrease in eGFR ( -14 ml/min/1.73 m2, p = 0.0005). Nevertheless, the average rate of decrease in eGFR was -2.8 ml/min/1.73 m2/year, which turned out to be significantly lower than those for the specified cohort according to literature sources (-6 ml/min/1.73 m2/year). In the dynamics of observation, eGFR was directly correlated with the volumes of the renal medulla (r = 0.78, p = ,005). Cystatin C correlated with the volume of the renal parenchyma (r = -0.88, p = ,000). Conclusions: RD is a successful way to reduce blood pressure in patients with RHT, allowing to slow down the rate of reduction in the amount of renal parenchyma and the progression of renal dysfunction during 5 years of follow-up.