PERIPHERAL VASCULAR DISEASE (M SHISHEHBOR, SECTION EDITOR) Renal Intervention to Treat Hypertension Rajan A. G. Patel & Christopher J. White Published online: 29 December 2011 # Springer Science+Business Media, LLC 2011 Abstract Renal artery intervention to treat hypertension is one of the frontiers of ongoing research in combating this epidemic. This article focuses on recent data regarding PTRS and catheter-based renal sympathetic denervation. Despite progress in this field large multicenter, randomized trials that compare these treatment modalities with medical therapy for hypertension are lacking. Keywords Renal artery stenosis . Renal artery stent . Embolic protection . Renal sympathetic denervation . Renal intervention . Hypertension Introduction By 2025, 30% of the estimated world population, representing 1.56 million people, is predicted to have hypertension [1]. Between the 1988 to 1994 and 1999 to 2004 editions of the National Health and Nutrition Examination Surveys, the stan- dardized prevalence rate of hypertension increased from 24.4% to 28.9% (P <0.001). Data from the 1990s demonstrate that only 29% of hypertension patients had blood pressure controlled at the 140/90-mm Hg threshold [2]. Clearly pre- vention is necessary to quench this epidemic. However, for the millions of patients with hypertension, more effective treat- ment strategies are necessary. Lifestyle modifications, dietary changes, and medications have been the mainstay of hypertension treatment. However, since the first human percutaneous transluminal dilation of a renal artery was described in 1978 [3], renal artery interven- tion to treat renovascular hypertension has been an area of active clinical research. Current research is focused on im- proving outcomes with percutaneous transluminal renal artery stent placement (PTRS) and sympathetic renal denervation. Many etiologies of renal artery stenosis (RAS) have been reported. Over 85% of RAS cases in non-transplant patients are due to atherosclerosis [4]. Another 10% of cases are due to fibromuscular dysplasia (FMD) [5, 6]. The American College of Cardiology and the American Heart Association have pub- lished guidelines for the treatment of RAS [7]. Significant RAS is defined as an angiographic stenosis greater than 70% of the reference vessel or a 50% to 69% stenosis with a translesional pressure gradient of ≥ 20 mm Hg. Intervention for significant RAS with a stent, rather than a balloon alone, has a class I indication. Percutaneous transluminal balloon angioplasty (PTA) alone is indicated for patients with FMD. Stent place- ment in FMD patients is reserved for balloon angioplasty failure or in those with restenosis. Recent research in renal artery dilation to treat hypertension has involved 1) assessment of variables to predict postprocedural hypertension control; 2) ascertaining which populations experience the most benefit or are at the most risk with regard to changes in renal function; 3) embolic/microvascular protection; 4) renal stent development; and 5) treatment of in-stent restenosis (ISR). Early clinical data regarding catheter-based renal sympathetic denervation to treat hypertension have recently been published. Other trials inves- tigating this technology are ongoing. Assessment Variables to Predict PTRS Success in Hypertension Management Fractional flow reserve (FFR) and hyperemic mean/systolic translesional gradients have been used to discern those R. A. G. Patel : C. J. White (*) Department of Cardiology, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA 70121, USA e-mail: cwhite@ochsner.org Curr Cardiol Rep (2012) 14:142–149 DOI 10.1007/s11886-011-0243-9