Renal Denervation: A Novel Therapy at the Crossroads of Imaging, Intervention, and Innovation

Abstract

Hypertension (HTN) is one of the most significant medical problems affecting society today. The estimated 76 million Americans with hypertension represent a significant public health problem, contributing to cardiac, vascular, renal, and neurovascular morbidity and mortality. HTN is the most common indication for lifelong pharmacologic treatment, mainly because of the incontrovertible reductions in cardiovascular events with blood pressure (BP) reduction and control. However, despite the availability and potency of multiple different antihypertensive drugs, up to half of American patients have BPs above the recommended target. Given the overwhelming evidence of both the cost to society of HTN and the benefits that are accrued from improved BP control, alternatives or adjuncts to current management options have been sought to aid in treatment of these patients. Over the past few years, a device-based approach involving modulation of the autonomic nervous system, termed renal denervation, has evolved to meet this challenge. With early trials showing startlingly good results, with few side effects, multiple devices were fast-tracked to clinical trials and hence to the market. However, larger trials have shone an unfavorable light on the field, with concerns about the short- and long-term effectiveness, diverting attention back to operational and procedural details. Despite this, image-guided manipulation of the sympathetic nervous system to treat HTN remains a fertile area of laboratory and clinical research.

Neuromodulation Therapy in Heart Failure: Combined Use of Drugs and Devices

“…Consequently, α-AR activation leads to renal vasoconstriction. 47 , 48 The NE level is reported to correlate with the development of HF. In addition, NE spillover in the heart is observed beginning in the early stage of HF, while its correlation in the kidney is more precise in severe HF.…”

“… 62 , 63 On the other hand, there was a 47% decrease in renal NE spillover and a 26% decrease in cardiac NE spillover at six months. Given the fact that renal spillover of NE is activated in HF patients and is predictive of mortality, 48 , 49 it is still conceivable that RND might have a positive impact on HF symptoms and outcomes. In addition, more than 90% of patients were taking ACEIs/ARBs and β-blockers for optimal medical therapy; accordingly, the study may have not had an appropriate design or the numbers may not have been enough to accurately detect the effects of RDN.…”