An analysis of the blood pressure and safety outcomes to renal denervation in African Americans and Non-African Americans in the SYMPLICITY HTN-3 trial

• The systolic blood pressure (SBP) change after renal denervation did not differ by race in SYMPLICITY HTN-3.
• The change in sham office SBP was, however, nearly twice as large in African Americans (AA) than non-AA.
• The ambulatory SBP response among sham subjects and the larger office sham SBP response in AA may represent increased post-randomization medication adherence.
• In multivariate analyses, sham SBP response appeared to be much larger in AA than non-AA prescribed a complex antihypertensive regimen.

SYMPLICITY HTN-3, the first trial of renal denervation (RDN) versus sham, enrolled 26% African Americans, a prospectively stratified cohort. Although the 6-month systolic blood pressure (SBP) reduction in African Americans (AAs) was similar in the RDN group (−15.5 ± 25.4 mm Hg, n = 85 vs. −17.8 ± 29.2, n = 49, P = .641), the sham SBP response was 9.2 mm Hg greater (P = .057) in AAs than non-AAs. In multivariate analyses, sham SBP response was predicted by an interaction between AA and a complex antihypertensive regimen (at least one antihypertensive medication prescribed ≥3 times daily), while in the RDN group, SBP response was predicted by an interaction between AA race and baseline BP ≥ 180 mm Hg. AA race did not independently predict SBP response in either sham or RDN. There appears to be effect modification by race with individual-level patient characteristics in both treatment arms that affect the observed pattern of SBP responses.