What are the benefits of renal denervation in patients with resistant hypertension?

Abstract

Systemic arterial hypertension is one of the most important public health issues, affecting more than one-quarter of the adult population in industrialized countries [1]. It is a major risk factor for cardiovascular disease morbidity and mortality [2,3]. In most patients, hypertension can be effectively managed by a combination of lifestyle interventions and medication [4]. However, a significant portion of patients treated for hypertension are resistant to therapy. Conventionally, resistant hypertension is defined as persistent elevation of blood pressure above goal levels despite the use of at least three hypertensive agents from different classes, including a diuretic, in optimal doses [5]. Current prevalence estimates suggest that 10–30% of patients with hypertension may be resistant to drug therapy [6]. Renal sympathetic overactivity seems to play a crucial role in the development of arterial hypertension and resistance to treatment. Activation of efferent renal sympathetic nerve fibers results in an increased renin secretion rate, increased renal vasoconstriction and enhanced sodium and water retention [7]. In addition, afferent sympathetic activation from the kidneys to the CNS, seems to enhance sympathetic nerve discharge itself again, leading to a vicious circle in the development of arterial hypertension and cardiovascular morbidity [8]. Both effects, the activation of efferent renal sympathetic nerve fibers as well as the afferent ‘feedback’ from the kidneys seem to play a crucial role in the pathogenesis and maintenance of arterial hypertension. The idea of treating arterial hypertension by targeting the autonomic nervous system is decades old. In the predrug era, treatment of malignant hypertension was limited to surgical approaches, such as nephrectomy and surgical lysis of the autonomic nerves. Nonselective surgical sympathectomy (thoracolumbar splanchnicectomy), the so-called Smithwick intervention,