Atrial Fibrillation Reduction by Renal Sympathetic Denervation

The estimated incidence of hypertension in the general population is estimated
to be between 30 and 40% and suboptimal blood pressure control is the largest
contributor to death worldwide. Despite the prevalence of hypertension and its
associated complications, control of the disease is far from adequate. The
prevalence of therapy resistant hypertension reaches up to 25% of all
hypertensive patients treated in Europe. Increased sympathetic nervous system
(SNS) activity has been documented in systolic-diastolic and isolated systolic
hypertension, in white coat and masked hypertension and pregnancy induced
hypertension by using sophisticated techniques for measuring adrenergic
activity.
A direct relationship has also been established between sympathicus nervous
activity and atrial fibrillation.
The contribution of the kidney*s somatic afferent nerves, as an underlying
cause of elevated central sympathetic drive, and the consequences of excessive
efferent sympathetic signals to the kidney itself, as well as other organs,
identify the renal sympathetic nerves as a logical therapeutic target for
diseases linked by excessive central sympathetic drive.
Renal sympathetic denervation is an emerging technology for the treatment of
therapy resistant hypertension. By one single invasive procedure taking about
45 minutes, approximately 4 to 8 radiofrequency ablations will be delivered to
each renal artery. Previous studies already showed that the technology is safe
and effective in patients with therapyresistent hypertension.
Thus far, no studies have been performed showing a decrease in atrial
fibrillation burden after renal denervation.

The objective of the present pilot study is to assess whether renal sympathetic
denervation will decrease atrial fibrillation burden in patients with
symptomatic paroxysmal of persistent atrial fibrillation

Single-arm pilot study of patients with symptomatic paroxysmal or persistent
AF. A St. Jude Medical Confirm ICM will be implanted 3 months before the renal
denervation to continuously monitor heart rate and rhythm during the entire
pre-procedural (baseline) and follow-up period.

A St. Jude Medical Confirm ICM will be implanted 3 months before the renal
denervation to continuously monitor heart rate and rhythm during the entire
pre-procedural (baseline) and 3 year follow-up period.

Placed percutaneously, the Simplicity renal denervation catheter will be
advanced into the renal artery using a routine femoral artery approach in a
cardiac catheterization laboratory setting. Radiofrequency ablation will be
applied by using an automated programmed algorhythm (pre-programmed time and
intensity)

As of June 2013, the use of implantable cardiac monitors has been part of our
routine clinical practice since over 10 years. In contrast to pacemakers or
ICD*s, no intracardiac leads will be placed, thereby reducing procedure time
and minimizing the risk of infections. Given the small caliber of the device
(only 12gr (dimensies 56*19*8mm)), the risk for pocket bleeding is minimal.

Patients will undergo thorough pre-procedure assessment and imaging assessment
(both MRI ultrasound) prior to selection and inclusion into the study. The
procedure is initiated by puncture of the femoral artery with its inherent
risks including bleeding, aneurysm formation, dissection, thrombosis and
perforation. However, these risks are not different from each comparable form
of angiography in which the groin is punctured and the access procedure is
known for its low and acceptable complication risk. An additional potential
procedure risk is caused by the radiofrequency ablation of the renal artery
with focal damage of the endothelium on the coagulation spots. However, study
data thus far do not show any signs of arterial damage due to the ablation
procedure.

Based on previous studies using the Simplicity renal denervation system in
approximately 350 patient, the following complications were recorded:
- damage to the blood vessels of the kidney in approximately 1% of the patients
- blood clots leading to heart attach or stroke in approximately 1-2%
- extended hospital stay in 1-2%
- pseudoaneurysm of the femoral artery in approximately 1-2% of the patients
- (temporarily) low blood pressure in 1-2% of the patients
- urinary tract infection in 1-2% of the patients
- renal artery stening in 1-2% of the patients
- arrhythmias during the procedure in 1-2%

In addition, in the recently published EnligHTN-I trial (n=46), assessing the
safety and efficacy of the St. Jude Medical EnligHTN renal denervation system,
no serious vascular adverse events occurred during the procedure. Serious
adverse events occurred in 3 patients; 1 patient suffered from hypertension
related renal disease progression, 1 patient developed symptomatic hypotension
for which antihypertensive drug-therapy was lowered and 1 patients showed
progression of a pre-existing renal artery stenosis. Noteworthy, none of the
patients developed a haemodynamically significant renal artery stenosis at 6
months.