CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 9, October 2012
524
AFRICA
Renal denervation in Symplicity trials and real-life setting
continue to show significant blood pressure reduction in all
treatment groups
Medtronic announced at the 2012
European Society of Cardiology (ESC)
congress in Munich, Germany, new
results from the Symplicity HTN-2
trial, the only randomised clinical trial
investigating safety and efficacy of renal
denervation. The 18-month follow-up data
presented at the ESC congress showed the
Symplicity system continues to provide
superior and sustained blood pressure
reduction in patients with treatment-
resistant hypertension. The safety of
renal denervation with the Symplicity
system was also maintained at 18 months,
with no device-related serious adverse
events and no newly reported vascular
complications from 12 to 18 months.
1
‘
We continue to see significant
and sustained improvement in blood
pressure levels for patients who receive
renal denervation with the Symplicity
system, as these 18-month average blood
pressure reductions are consistent with
the 12-month follow-up data for both
groups’, said Murray Esler, principal
investigator of the Symplicity HTN-2 trial
and associate director of the Baker IDI
Heart andDiabetes Institute ofMelbourne,
Australia. ‘This is encouraging since
patients
with
treatment-resistant
hypertension are often taking more than
three antihypertensive medications and
are still unable to control their blood
pressure, which can put them at risk
for various cardiovascular events such as
heart attack, stroke or heart failure.’
In this trial, 43 patients initially
randomised to renal denervation with the
Symplicity system had an average blood
pressure reduction of –32/–12 mmHg
from baseline (
p
<
0.01)
at 18 months.
Thirty-one control patients who received
renal denervation following the six-month
primary endpoint (crossover group) had
an average blood pressure reduction of
–28/–11
mmHg (
p
<
0.01)
at 18 months.
These 18-month average blood pressure
reductions were maintained for both
groups from the 12-month follow up
[–28/–10
mmHg (
p
<
0.01)
for the initial
treatment group; –24/–10 mmHg (
p
<
0.01)
for the crossover group].
The average number of medications for
patients in this trial did not change from
baseline to 18 months. At 18 months,
pulse pressure improved significantly
for patients in this analysis following
treatment with the Symplicity system
[–20
mmHg from baseline for the initial
treatment group (
p
<
0.01); –18
mmHg
from baseline for the crossover group (
p
<
0.01].
Pulse pressure is the numeric difference
between systolic and diastolic blood
pressure and may have predictive value
in terms of cardiovascular complications,
especially in older patients. It may be
important to evaluate changes in pulse
pressure as well as systolic and diastolic
blood pressurewhen assessing the efficacy
of antihypertensive therapy. This analysis
showed three new hospitalisations in the
initial renal denervation group due to
hypertensive events.
The Symplicity system’s catheter and
proprietary generator and algorithms
were carefully and specifically developed
through years of clinical experience to
enhance the safety and effectiveness of
the renal denervation procedure. The
Symplicity renal denervation system has
been successfully used for five years to
treat nearly 5 000 patients with treatment-
resistant hypertension worldwide. It
is not approved by the US Food and
Drug Administration for commercial
distribution in the United States.
Transcatheter renal denervation repre-
sents a novel therapy for treating patients
with treatment-resistant hypertension, a
condition which greatly increases the risk
of myocardial infarction and stroke.
Further evidence of the value
of renal denervation in clinical
practice
‘
The Symplicity Hypertension I and II
studies have suggested that this procedure
significantly lowers blood pressure in
those patients with few remaining options
in terms of treatment’, said Dr Mylotte,
Paris. ‘However, patients included in
clinical trials are often highly selected,
and therefore may not reflect the typical
patient encountered by physicians on a
day-to-day basis. Therefore the results of
these trials may not be applicable to less-
selected patient populations.’
In light of this potential problem,
the investigators sought to evaluate the
effect of transcatheter renal denervation
in a group of patients with resistant
hypertension in their own clinical practice
at the Institut Cardiovasculaire de Paris
Sud, Paris, France. The study intended to
perform transcatheter renal denervation
on 35 consecutive patients referred to
the service with resistant hypertension.
The study used the same definition as
the Symplicity trials to define resistant
hypertension.
2
Among these patients, 36.5% were
female, 36.4% were diabetic, and
15.2%
had kidney dysfunction. Baseline
office blood pressure (BP) was 181.1
±
21.9/100.8
±
16.8
mmHg, despite an
average of 4.6
±
1.0
medications per
patient. Successful bilateral sympathetic
denervation was performed in 33 out of
35
patients (one patient was not treated
due to a stenosis of the renal artery;
one patient had treatment on one side
only, as multiple small renal arteries were
found on the other side). No procedural
complications occurred.
At six months’ follow up, the average
office BP reduction from baseline was
30.3
±
21.1/14.6
±
15.3
mmHg (
p
<
0.0001).
Similarly, ambulatory BP was
reduced 23.3
±
12.1/10.2
±
9.9
mmHg
from baseline (
p
<
0.001).
There were no
adverse events during follow up (death,
myocardial infarction or stroke) and
no deterioration in renal function was
observed.
‘
Transcatheter renal denervation is a
safe and efficacious treatment, which
results in significant reductions in blood
pressure in real-world patients with
treatment-resistant hypertension’, said Dr
Mylotte. ‘Although longer-term results
are required, renal denervation should be
considered for all patients with treatment-
resistant hypertension, as it is likely to
lower their blood pressure and reduce
their chances of myocardial infarction
and stroke.’
3
J Aalbers
1.
Abstract 116, 2012 ESC Congress.
2.
Esler MD, Krum H, Sobotka PA, Schlaich
MP, Schmieder RE, Böhm M, Symplicity
HTN-2 investigators.
Lancet
2010;
376
:
1903–1909.
3.
ESC press release, 27 Aug 2012.
