Renal Denervation Ultima Ratio or Standard in Treatment-Resistant Hypertension

Depending on studied populations and applied definitions, the prevalence of treatment-resistant hypertension (rHT) varies from 10% to 15%, but is higher in conditions associated with increased sympathetic drive, such as obesity, obstructive sleep apnea, diabetes or renal dysfunction. The SYMPLICITY studies recently demonstrated that reducing sympathetic tone by intravascular renal denervation (IRD) is feasible in rHT, but did not provide conclusive evidence on the size and durability of the antihypertensive, renal and sympatholytic effects, long-term safety, quality of life, the possibility to relax antihypertensive drug treatment, cost-effectiveness, and benefit in terms of long-term hard cardiovascular-renal outcomes. At the time of writing of this report, 28 IRD trials in various indications were registered at http://www.clinicaltrials.gov, but only seven had a randomized controlled design. In the US, IRD remains an investigational procedure that cannot be used in clinical practice, but in Europe, CE-label certification of electrical safety is permitting to market catheter systems to any interventional facility for regular clinical use. IRD should not be routinely applied as a substitute for the skilful management of resistant patients, which includes documentation of adherence to antihypertensive drugs, implementation of lifestyle measures and the use of recommended combinations of antihypertensive agents at the highest tolerated daily dose. For now, IRD should therefore remain the ultima ratio in adherent patients with severe rHT, in whom all other efforts to reduce blood pressure have failed. IRD should only be offered within a clinical research context at highly skilled tertiary referral centers that participate in international registries constructed independent of the manufacturers.