313were racial differences in antihypertensive RDN effects. In a group of non-African-
Americans, office systolic blood pressure was decreased by 15 mmHg after RDN
and 9 mmHg after sham procedure (the difference was significant). No significant
difference was observed in African-Americans between RDN and sham group
(reduction in office SBP was 15 mmHg and 18 mmHg, respectively). Moreover in
39% of patients, changes in antihypertensive medication during the study period
were noted. Symplicity HTN-3 study confirmed, however, that RDN seems to be
safe.
Results of two randomized studies comparing RDN with intensified drug treat-
ment in patients with resistant hypertension were recently published – DENER-
HTN and PRAGUE-15 study. In the DENER-HTN study, 106 patients with resistant
hypertension were randomly assigned to receive either RDN (with the use single RF
electrode catheter Symplicity) together with standardized intensification of medical
antihypertensive therapy or standardized intensification of medical antihypertensive
therapy alone (control group). In this trial, blood pressure reduction after 6 months
follow-up was significantly greater in the interventional than in the control group
(systolic daytime and nighttime blood pressure differences between groups were
6/6 mmHg, respectively). Results of the study acknowledge superiority of renal
denervation over the intensification of pharmacological treatment of resistant hyper-
tension. In the PRAGUE-15 study, 106 patients with resistant hypertension were
randomly assigned to receive either renal denervation (with the use single RF elec-
trode catheter Symplicity) or to intensify pharmacological treatment including spi-
ronolactone (if tolerated) [ 13 ]. In this study, antihypertensive effect of RDN was
similar to group with intensified medical treatment (significant reduction in 24 h
ABPM SBP after 6 months 9 vs 8 mmHg, respectively).
Recently, Desch et al. published results of a randomized, sham-controlled study
in patients with so-called mild resistant hypertension. In this study, 71 patients with
mild resistant hypertension were randomly allocated to RDN (with Symplicity
FLEX catheter) or sham procedure (control group). Six months after procedure, 24
h ABPM systolic blood pressure reduction was similar in studied groups (7 vs 4
mmHg, respectively) [ 14 ].
Despite whole spectrum of clinical studies (i.e., intervention vs control vs sham
procedure vs standardized pharmacotherapy), effectiveness of RF RDN ablation in
hypertensive patients is still a matter of debate and needs further studies.
Another agent used to induce renal nerve damage is ultrasound energy. Catheters
in renal arteries emitting ultrasound energy generate heat resulting in degeneration
of renal nerves. The systems PARADISE and TIVUS utilize such energy [ 15 ].
PARADISE (ReCor Percutaneous Renal Denervation System) catheter consists of
self-centering ultrasonic wave generator and balloon. The ultrasonic sound waves
emitted from the central core of the balloon produce frictional heating of soft tissues
outside of the artery leading to circumferential ablation of renal SNS nerves, while
the fluid-filled balloon cools the endoluminal surface of the artery. Therefore
endothelium is protected by cooled fluid inside inflated balloon. Additionally, using
ultrasound probe allows to eliminate contact between the device and vessel wall.
Preliminary clinical data from 11 patients showed the reduction of office SBP of 36
19 Devices for Neural Modulation (Renal Denervation, Barostimulation)