Renal Denervation in the Management of Resistant Hypertension

Current Evidence and Perspectives

Yu Jin; Alexandre Persu; Jan A. Staessen

Disclosures

Curr Opin Nephrol Hypertens. 2013;22(5):511-518. 

In This Article

Abstract and Introduction

Abstract

Purpose of review: Catheter-based renal denervation has emerged as a novel treatment modality for resistant hypertension. This review summarizes the current evidence on this procedure in treatment of resistant hypertension, limitations of available evidence and questions to be answered.

Recent findings : The SYMPLICITY studies showed that renal denervation is feasible in treating resistant hypertension, but failed to provide conclusive evidence on the size and durability of the antihypertensive, renal and sympatholytic effects, as well as the long-term safety. The definition of resistant hypertension was loose in the SYMPLICITY studies and the management of resistant hypertension was suboptimal. Future studies should have a randomized design and enroll truly resistant hypertension patients by excluding secondary hypertension, white-coat hypertension and nonadherent patients. Questions to be addressed by the ongoing and future trials include the long-term efficacy and safety of this procedure, identification of responders and uncovering of the underlying mechanisms.

Summary : Only well-designed, randomized clinical trials addressing the limitations of the SYMPLICITY studies will be able to demonstrate whether renal denervation is an efficacious treatment modality in resistant hypertension and in which patients. For now, renal denervation remains an experimental procedure and should only be offered to truly resistant hypertensive patients in a research context after careful selection.

Introduction

Hypertension affects approximately 20–30% of the world's adult population.[1] Resistant hypertension (rHT) is defined as a blood pressure that remains above goal while treated with three or more classes of antihypertensive drugs, preferably including a diuretic.[2,3] All doses should be optimal. The prevalence of rHT varies from 10 to 15% depending on the study population and definitions.[4,5,6] rHT is more likely to occur in patients with increased sympathetic drive,[7–9] such as obesity, diabetes, renal dysfunction or obstructive sleep apnea. rHT patients are at high risk of cardiovascular complications.[5,10] However, until recently, treatment options were limited and mainly focused on lifestyle interventions and intensified pharmacologic treatment.

Renal sympathetic nerves play an important role in regulating blood pressure. The efferent sympathetic nervous outflow to the kidney stimulates renin release, promotes sodium and water retention, and reduces renal blood flow.[11] Afferent sympathetic fibers transfer signals from the kidney to central nervous system and thereby contribute to the neurogenic elevation of blood pressure.[12] Afferent and efferent nerve fibers form a neural network located within adventitia of the renal artery. Sympathetic nervous drive to the kidney is increased in hypertensive patients,[13] particularly in rHT patients.[14] Recently, catheter-based ablation of the renal nerves running through the renal arterial wall emerged as a novel treatment modality.

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