Distal Renal Denervation to Prevent Renal Function Decline in Patients With T2DM and Hypertension (REFRAIN)

Efficacy of Distal Renal Denervation for Preventing Decline in Renal Function in Patients With Type 2 Diabetes Mellitus and Hypertension

The aim of this study is to test the hypothesis that distal renal denervation (RDN) may delay or prevent the progressive decline of renal function in patients with type 2 diabetes mellitus and hypertension

Detailed Description: Diabetes mellitus and hypertension are two major causes of chronic kidney disease (CKD) that starts as subclinical decline in renal function that silently progresses to symptomatic advanced stages associated with irreversible significant damage of the kidney structure. Recent major improvements in pharmacotherapy of hypertension and diabetes have substantially reduced the prevalence of cardiovascular complications, yet, the frequency of CKD remains largely unchanged. Renal denervation is a new minimally invasive method to create regional blockade of the renal sympathetic nerves that is currently used as non-pharmacological therapy of hypertension. The CKD is likewise mediated by overactivity of renal sympathetic system so that RDN has strong potential to prevent development or progression of CKD. The new anatomically optimized distal RDN may have additional benefit in this regard. Denervation of the distal vessels involved in tonic regulation of renal blood should cause a significant drop in renal vascular resistance and proportional increase in blood and oxygen supply to the kidney preventing/reducing chronic hypoxia of renal tissue that is major mechanism of CKD. The aim of this study is to prove the aforementioned concept. For this purpose the eligible patients with type 2 diabetes mellitus and hypertension will undergo distal renal denervation performed using dedicated radiofrequency catheter Symplicity Spyral. The changes in the kidney function and structure as well as BPs (office and ambulatory) will be assessed at baseline, 6 and 12 months post-procedure

The arm comprises patients undergoing distal bilateral radiofrequency renal denervation performed using Symplicity Spyral renal denervation system.

Bilateral radiofrequency renal denervation will be performed using Symplicity Spyral renal denervation system. Generally, at least two separate applications of radiofrequency energy will be performed in each segmental branch of renal artery. Each application will be done through 4 electrodes deployed in helical manner according to the design of the catheter

Change in ambulatory 24-hour blood pressure levels (24-h mean, daytime, nighttime; systolic/diastolic)

Mean values for respective periods calculated from ambulatory blood pressure monitoring performed using automatic measurement device

Will be assessed from multiple regression model of linear dependence of change in eGFR on a number of independent variables including in addition to HbA1c also age, sex, baseline eGFR, and 24-h ambulatory systolic BP

blood flow velocity assessed by Doppler flowmetry in the trunk of the renal arteries and in segmental renal arteries using averaged values

Inclusion Criteria: informed consent of participation in the study; systolic BP > 140 or diastolic BP > 90 mm Hg; type 2 diabetes mellitus (glucose tolerance test > 11.0 mmol/l, HbA1c>6,5%); Exclusion Criteria: secondary hypertension; type 1 diabetes mellitus; acute renal failure; traumatic kidney injury; toxic kidney injury; CKD G4 and G5 according to the KDIGO 2012; infectious diseases requiring active antibacterial and/or antiviral therapy; other severe diseases and conditions