Renal sympathetic nerve activity after catheter-based renal denervation

Area of Science:

• Cardiology
• Interventional Cardiology
• Nephrology

Background:

• Catheter-based renal sympathetic denervation (RDN) is a potential therapy for resistant hypertension (RHT).
• Previous randomized trials showed limited blood pressure reduction following RDN.
• Incomplete nerve disruption may contribute to variable RDN efficacy.

Purpose of the Study:

• To investigate the relationship between RDN efficacy and renal nerve disruption.
• To assess changes in renal ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) uptake and washout post-RDN.
• To evaluate the impact of RDN on blood pressure, catecholamines, and plasma renin activity.

Main Methods:

• ¹²³I-mIBG scintigraphy was performed before and 6 weeks after RDN in 21 RHT patients.
• Blood pressure, plasma- and urinary-catecholamines, and plasma renin activity were assessed.
• Renal ¹²³I-mIBG uptake and washout were quantified using planar scintigraphy.

Main Results:

• Office systolic blood pressure decreased post-RDN (172 to 153 mmHg, p=0.036), but other BP parameters, PRA, and catecholamines showed no significant changes.
• No significant differences were observed in renal ¹²³I-mIBG uptake or washout post-RDN.
• No correlation was found between the number of denervations and ¹²³I-mIBG parameters.

Conclusions:

• RDN did not alter renal ¹²³I-mIBG uptake or washout at 6 weeks.
• These findings suggest incomplete renal denervation may underlie the limited efficacy of RDN in RHT.
• Further research is needed to optimize RDN techniques for improved outcomes.