Anatomical and procedural determinants of catheter-based renal denervation

Background/Purpose: Catheter-based renal sympathetic denervation ( RDN) can reduce blood pressure ( BP) and sympathetic activity in certain patients with uncontrolled hypertension. Less is known about the impact of renal anatomy and procedural parameters on subsequent BP response. Methods/Materials: A total of 564 patients with resistant hypertension underwent bilateral RDN in 9 centers in Europe and Australia using a mono-electrode radiofrequency catheter ( Symplicity Flex, Medtronic). Anatomical criteria such as prevalence of accessory renal arteries ( ARA), presence of renal artery disease ( RAD), length, and diameter were analyzed blinded to patient's characteristics. Results: ARA was present in 171 patients ( 30%), and RAD was documented in 71 patients ( 13%). On average 11 +/- 2.7 complete 120-s ablations were performed, equally distributed on both sides. After 6 months, BP was reduced by 19/8 mmHg ( p < 0.001 for both). Change of systolic blood pressure ( SBP) was not related to the presence of ARA (-18 vs. -20 mmHg; p = NS) or RAD (-16 vs. -20 mmHg; p = NS). Patients with a bilateral diameter = 4 mm had a more pronounced reduction of SBP compared to patients with a unilateral diameter = 4 mm or a bilateral diameter >4 mm (-29 vs. -26 vs. -17 mmHg; p < 0.001). Neither the length of the renal artery nor the number of RF ablations influenced BP reduction after 6 months. Conclusions: The diameter of renal arteries correlated with SBP change after RDN at 6-month follow-up. Change of SBP was not related to the lengths of the renal artery, presence of ARA, RAD, or the number of RF ablations delivered by a mono-electrode catheter. (C) 2016 Elsevier Inc. All rights reserved.