Renal Sympathetic Denervation Therapy for Resistant Hypertension

Resistant hypertension (RHTN) is defined as the failure to achieve goal blood pressure (BP), despite adherence to maximally tolerated doses of an appropriate regimen of 3 antihypertensive agents, including a diuretic.1,2 Interest surrounding its evaluation, diagnosis, and treatment has gained significant momentum for the following several reasons: (1) the recognition that patients with true RHTN appear to lie at the extreme end of an already high-risk cardiovascular (CV) morbidity and mortality continuum3–5; (2) the acceptance that accurate estimates of the incidence and prevalence of RHTN remain largely unknown5–8; (3) the need to establish robust prognostic associations to benchmark the degree of benefit gained from timely and consistent management; (4) the need to define the optimal pharmacotherapeutic regimen for RHTN; (5) evidence that RHTN may, at least in part, be mediated by chronic activation of the sympathetic nervous system (SNS)9; and (6) the subsequent emergence of percutaneous sympathetic denervation of the renal arteries—a novel intervention that could stimulate a paradigm shift in the way we manage not only treatment-resistant systemic HTN, but also a myriad of pathophysiological entities associated with chronically augmented SNS activation.10In this review we focus on the evolution of renal sympathetic denervation (RSDN) therapy; its role in the management of RHTN; current trial data; the wider application of renal denervation in the treatment of heart failure (HF), arrhythmia, and the metabolic syndrome; and emerging technologies for this potential device-based standard of care.The renal SNS comprises a dense network of postganglionic efferent fibers that run from the hypothalamus to the kidney via pre- and paravertebral sympathetic ganglia (T10–L2).11,12 Afferent renal sympathetic nerves emerge predominantly from the renal pelvic wall, where mechanoreceptors respond to stretch and chemoreceptors detect renal ischemia and alterations of the biochemical …