Kidney protection study (KPS 1) is a prospective randomized clinical study comparing the use of renal denervation (RDN) and optimal medical therapy in subjects with chronic kidney disease stage 3-4 and resistant arterial hypertension to optimal medical therapy alone. Renal denervation is a modern endovascular method used to treat resistant hypertension. The method is being extended to other groups of patients, where the sympathetic tone is increased beyond resistant hypertension. Because of the character of the disease, we hypothesize that renal denervation can reduce or prevent progressive deterioration of kidney functions in this patient population. The aim of this clinical study is to show that renal denervation has protective effects on the progression of chronic renal insufficiency.