Renal denervation for resistant hypertension and beyond

Renal Denervation for the Treatment of Hypertension: A Scientific Statement From the American Heart Association

Hypertension is a leading risk factor for cardiovascular morbidity and mortality. Despite the widespread availability of both pharmacological and lifestyle therapeutic options, blood pressure control rates across the globe are worsening. In fact, only 23% of individuals with high blood pressure in the United States achieve treatment goals. In 2023, the US Food and Drug Administration approved renal denervation, a catheter-based procedure that ablates the renal sympathetic nerves, as an adjunctive treatment for patients in whom lifestyle modifications and antihypertensive medications do not adequately control blood pressure. This approval followed the publication of multiple randomized clinical studies using rigorous trial designs, all incorporating renal angiogram as the sham control. Most but not all of the new generation of trials reached their primary end point, demonstrating modest efficacy of renal denervation in lowering blood pressure across a spectrum of hypertension, from mild to truly resistant. Individual patient responses vary, and further research is needed to identify those who may benefit most. The initial safety profile appears favorable, and multiple ongoing studies are assessing longer-term efficacy and safety. Multidisciplinary teams that include hypertension specialists and adequately trained proceduralists are crucial to ensure that referrals are made appropriately with full consideration of the potential risks and benefits. Incorporating patient preferences and engaging in shared decision-making conversations will help patients make the best decisions given their individual circumstances. Although further research is clearly needed, renal denervation presents a novel treatment strategy for patients with uncontrolled blood pressure.

Renal sympathetic denervation for resistant hypertension: where do we stand after more than a decade

Despite the current availability of safe and efficient drugs for treating hypertension, a substantial number of patients are drug-resistant hypertensives. Aiming this condition, a relatively new approach named catheter-based renal denervation was developed. We have now a clinically relevant time window to review the efficacy of renal denervation for treating this form of hypertension. This short review addresses the physiological contribution of renal sympathetic nerves for blood pressure control and discusses the pros and cons of renal denervation procedure for the treatment of resistant hypertension.

Potential Therapeutic Use of Neurosteroids for Hypertension

The sympathetic nervous system (SNS) contribution to long-term setting of blood pressure (BP) and hence hypertension has been a continuing controversy over many decades. However, the contribution of increased sympathetic vasomotor tone to the heart, kidney, and blood vessels has been suggested as a major influence on the development of high BP which affects 30-40% of the population. This is relevant to hypertension associated with chronic stress, being overweight or obese as well to chronic kidney disease. Treatments that have attempted to block the peripheral aspects of the SNS contribution have included surgery to cut the sympathetic nerves as well as agents to block α- and β-adrenoceptors. Other treatments, such as centrally acting drugs like clonidine, rilmenidine, or moxonidine, activate receptors within the ventrolateral medulla to reduce the vasomotor tone overall but have side effects that limit their use. None of these treatments target the cause of the enhanced sympathetic tone. Recently we have identified an antihypertensive action of the neurosteroid allopregnanolone in a mouse model of neurogenic hypertension. Allopregnanolone is known to facilitate high-affinity extra-synaptic γ-aminobutyric acid A receptors (GABA_AR) through allosteric modulation and transcriptional upregulation. The antihypertensive effect was specific for increased expression of δ subunits in the amygdala and hypothalamus. This focused review examines the possibility that neurosteroids may be a novel therapeutic approach to address the neurogenic contribution to hypertension. We discuss the causes and prevalence of neurogenic hypertension, current therapeutic approaches, and the applicability of using neurosteroids as antihypertensive therapy.