Comparison of Best Medical Treatment Versus Best Medical Treatment Plus Renal Artery Stenting

Inclusion Criteria: * Age ≥ 18 years * Informed consent signed by patient (and/or legal guardian), * Hemodynamically relevant de novo unilateral or bilateral atherosclerotic renal artery diameter stenosis RAS (≥ 70%) * Estimated GFR \> 10 ml/min calculated using the abbreviated Modification of Diet in Renal Disease (MDRD) Study equation, * Patients presenting mild, moderate or severe hypertension (defined according to the WHO guidelines) and/or renal dysfunction, * Target lesion must be completely coverable by one study stent, * Total target lesion length estimated to be less than 19 mm, * Target lesion accessible to direct stenting or, after pre-dilation, is likely to sufficiently benefit from stenting (at the discretion of the investigator), * Renal reference vessel diameter (RVD) of ≥ 4.0 mm and \< 7.0 mm based on visual estimation, * Willingness to comply with all the specified follow-up evaluations. Exclusion Criteria: * Estimated GFR ≤ 10 ml/min, * Renal atrophy or kidney length \< 7cm (referring to kidney with target lesion), * Patient not eligible for PTRAS, * Patient not eligible for stenting, * Target lesion occlusion, * Target lesion and/or target vessel proximal to the target lesion is severely calcified, * Treatment of branch lesion required, * Fresh thrombus or embolic lesion * Need for embolic protection in previous or planned PTRAS, * Clotting disorders, * INR \> 2.5 before the intervention, * Patient presents fibromuscular dysplasia, * Prior revascularization of target lesion, * History of target vessel revascularization within the last six months, * Angiographic restenosis of any segment of the target vessel that has undergone prior percutaneous intervention, * Any thrombolytic therapy procedure within 72 hours prior to planned study procedure * Active peptic ulcer or gastro intestinal bleeding, * Active inflammation of the kidney interfering with diagnosis and treatment of RAS (e.g. glomerulonephritis, aortitis, vasculitis), * Radiation damage of the kidney, * Renal disease associated with aortic aneurysm i.e. diameter of the aorta \> 40 mm, * Chronic renal replacement therapy, * Life expectancy \< 1 year, * Co-morbid conditions limiting participation and follow-up * Patient currently participating in another trial possibly influencing the safety of the patient and/or the outcomes of the study, * Pregnancy/Planned pregnancy/Childbearing potential without sufficient measures to prevent pregnancy as judged by the investigator, * Known allergy to contrast medium that cannot be adequately controlled with pre-medication, * Known intolerance against acetylic-salicylic acid (ASA), heparin, clopidogrel and ticlopidin, cobalt-chromium, * Metformin intake not stopped at least 48 hours before the intervention