Renal Nerve Denervation, Adherence, and Management of Resistant Hypertension
Since publication of the Symplicity HTN-3 results in 2014, which reported a similar blood pressure (BP) reduction in subjects with resistant hypertension who had either renal nerve denervation (RND) or sham intervention, there has been much discussion as to whether RND truly provides antihypertensive benefit.1 The discussion has included suggestions that RND functionally does very little, if anything, such that any associated BP reductions are placebo-related; that observed benefit with RND is likely a consequence of a large regression to the mean effect in patients with high baseline BP values; and/or, in the case of Symplicity HTN-3, inadequate nerve ablation by interventionalists inexperienced with the RND procedure resulting in reduced treatment benefit. There has also been concern that changes in medication adherence by patients participating in RND trials, particularly immediately after having the procedure done or not, might be confounding the observed results. To explain the BP reductions in both the truly treated and sham treated groups that occurred in Symplicity HTN-3, one would have to suppose that the procedure had little effect and both patient groups were suddenly, but equally more adherent after randomization, such that the similar BP reductions were simply attributable to patients actually taking their medications; or, alternatively, that the procedure did have a true antihypertensive effect that was, however, obscured by increased medication adherence in the sham treated patients. Since Symplicity HTN-3 did not include biochemical assessment of medication adherence such consideration has had to remain speculative.
- Received July 17, 2016.
- Accepted July 25, 2016.