Predictors of the preservation of renal parenchyma volume after renal denervation in patients with resistant hypertension according to magnetic resonance imaging

Abstract

Objective. To define the indicators that allow predicting the preservation of the volume of the renal parenchyma according to magnetic resonance imaging (MRI) data in resistant arterial hypertension (RHT) one year after renal denervation (RDN).Design and methods. The study included 66 patients with RHT (average age 57,6 ± 9,4 years). Anamnesis, renal MRI data, results of the 24-h ambulatory blood pressure (BP) monitoring, lipid profile, serum markers of renal dysfunction initial and 1 year after RDN were analyzed. The group with preserved renal parenchyma volume consisted of 30 patients; the group with reduced renal parenchyma volume included 36 patients. Renal MRI was performed with the use of a 1,5 T device. Kidney volumes were calculated by the ellipsoid formula (Total kidney volume, TKV) and by the modified ellipsoid formula — the volume of the cortical layer (Total Cortex Volume, TCortexV). In addition, indices of renal parenchyma volumes adjusted for height are proposed for analysis: htTKV = TKV/height2,7 and htTCortexV = TCortexV/height2,7.Results. Univariate logistic regression analysis showed that statistically significant predictors of the preservation of renal parenchyma volume 1 year after RDN are lower initial values of htTKV (p = 0,02) and htTCortexV (p = 0,033), absence of diabetes mellitus type 2 (p = 0,03), lower pulse BP (p = 0,013) and younger age at the time of RDN (p = 0,03). Multivariate regression analysis, taking into account all variables, showed that the logistic regression model included the following independent predictors of renal parenchyma volume retention 1 year after RDN: age at the time of RDN (odds ratio (OR) 1,06 (confidence interval (CI) 0,99–1,13)), absence of chronic kidney disease (CKD) (OR 0,08 (CI 0,02–0,46)), htTCortexV (OR 0,89 (CI 0,82–0,96)), pulse BP (OR 0,94 (CI 0,91–0,99)), body mass index (BMI) (OR 0,95 (CI 0,85–1,07)).Conclusions. Predictors of the preservation of renal parenchyma volume include: lower age at the time of RDN, absence of CKD, lower values of htTCortexV calculated from MRI data, lower values of pulse blood pressure and BMI. These parameters can be used for the selection of patients with RHT for the RDN.