The Medical and Endovascular Treatment of Atherosclerotic Renal Artery Stenosis (METRAS) study: rationale and study design

It is unclear whether revascularization of renal artery stenosis (RAS) by means of percutaneous renal angioplasty and stenting (PTRAS) is advantageous over optimal medical therapy. Hence, we designed a randomized clinical trial based on an optimized patient selection strategy and hard experimental endpoints. Primary objective of this study is to determine whether PTRAS is superior or equivalent to optimal medical treatment for preserving glomerular filtration rate (GFR) in the ischemic kidney as assessed by 99mTcDTPA sequential renal scintiscan. Secondary objectives of this study are to establish whether the two treatments are equivalent in lowering blood pressure, preserving overall renal function and regressing target organ damage, preventing cardiovascular events and improving quality of life. The study is designed as a prospective multicentre randomized, un-blinded two-arm study. Eligible patients will have clinical and angio-CT evidence of RAS. Inclusion criteria is RAS affecting the main renal artery or its major branches either >70% or, if