The Sympathetic Nervous System

Renal sympathetic nerve hyper-activation leads to renin secretion, sodium reabsorption and decreased renal perfusion. Increased sympathetic nerve activity plays a key role in the pathophysiology of essential hypertension.1, 2 The overactive sympathetic nervous system not only plays a role in hypertension, but may also have a role in heart failure, kidney disease, metabolic syndrome and sleep apnea.3

In the past, sympathectomy (surgical cutting of a sympathetic nerve) to interrupt this oversignaling was performed in patients with severe hypertension. The surgery did lead to a reduction in blood pressure, but was a highly invasive procedure.2, 3

1 2 3

Renal Denervation (RDN)

For patients unable to effectively control their blood pressure with lifestyle changes and medication therapy, a new class of interventional products have been under development this past decade as an investigational treatment of hypertension using a procedure called renal denervation. This investigational procedure ablates the sympathetic nerves in order to reduce their overactivity. Most recently, data from three sham-controlled renal denervation trials using second-generation technology showed similar consistent decreases in blood pressure.4 The 2023 ESH guidelines acknowledge the safety of RDN based on the available data and that RDN represents a treatment option that is additive or alternative to increasing medication in patients with uncontrolled resistant hypertension who do not have a secondary cause of hypertension.These guidelines state that selection of patients to whom RDN is offered should be done in a shared decision-making process after objective and complete patient information. These guidelines also state that RDN should only be performed in experienced specialized centers to guarantee appropriate selection of eligible patients and completeness of the denervation procedure.

1 Mahfoud et al, Catheter-based renal denervation in hypertension: heading for new shores, J Hypertens. 2018 January ; 36(1): 41–42

2 Sverre E. Kjeldsen, Krzysztof Narkiewicz, Michel Burnier & Suzanne Oparil (2018) Renal denervation achieved by endovascular delivery of ultrasound in RADIANCE-HTN SOLO or by radiofrequency energy in SPYRAL HTN-OFF and SPYRAL-ON lowers blood pressure, Blood Pressure, 27:4, 185-187, DOI: 10.1080/08037051.2018.1486178

3 Fisher et al, Central Sympathetic Overactivity: Maladies and Mechanisms, Auton Neurosci. 2009 June 15; 148(1-2): 5–15. doi:10.1016/j.autneu.2009.02.003

4 Schmieder et al, European Society of Hypertension Position Paper on Renal Denervation 2018, Journal of Hypertension 2018 Oct;36(10):2042-2048.

5 Mancia G, Kreutz R, Brunstrӧm M, et al. 2023 ESH guidelines for the management of arterial hypertension the task force for the management of arterial hypertension of the European Society of Hypertension: Endorsed by the International Society of Hypertension (ISH) and the European Renal Association (ERA). J Hypertens. 2023;41(12):1874-2071