Renal denervation therapy for resistant hypertension

Hypertension is common and leads to significant cardiovascular morbidity and mortality. Some patients are unable to achieve target blood pressures despite multiple antihypertensive medications; these patients are labeled as having resistant hypertension. To palliate the lack of pharmacologic options, recent technological advances led to the development of an interventional procedure to treat hypertension, namely renal sympathetic denervation. This percutaneous procedure involves the ablation of the afferent and efferent nerves surrounding the renal arteries. Many studies that were primarily observational in nature had very promising results. Systolic blood pressure reductions in the order of 25-30 mm Hg were observed in a series of unblinded studies, leading to the approval and widespread use of this technology across Europe, Australia, and Canada. However, a recent rigorous single blinded sham-controlled clinical trial failed to meet its efficacy endpoints. There are several postulated reasons for the conflicting results, which are discussed in this manuscript. These recent findings make us reflect on the need for rigorous clinical trials prior to the early approval and clinical adoption of novel technologies. At the moment, renal denervation remains an investigational procedure. Several trials are underway using different technologies, which, upon completion, will clarify the proper role of renal denervation for the treatment of patients with resistant hypertension.