Renal nerve stimulation: complete versus incomplete renal sympathetic denervation

Area of Science:

• Cardiology
• Nephrology
• Vascular Surgery

Background:

• Blood pressure reduction after renal sympathetic denervation (RDN) is variable.
• Renal nerve stimulation (RNS) can identify sympathetic nerves and assess denervation completeness.

Purpose of the Study:

• To investigate the medium-term blood pressure (BP)-lowering effects of using RNS during RDN.
• To explore RNS's utility in verifying the completeness of renal denervation.

Main Methods:

• Prospective trial involving 44 treatment-resistant hypertensive patients.
• Primary endpoint: change in 24-h BP at 6-12 months post-RDN.
• Secondary endpoints: RNS-induced BP response pre- and post-RDN, medication changes, and correlation between RNS response and BP reduction.

Main Results:

• RNS-induced systolic BP rise decreased from 43 mmHg pre-RDN to 9 mmHg post-RDN (p < 0.001).
• Mean 24-h BP decreased significantly post-RDN (systolic: 147 to 135 mmHg, diastolic: 82 to 76 mmHg, p < 0.001).
• A significant correlation was found between the change in RNS-induced BP and 24-h BP reduction (systolic R=0.44, diastolic R=0.48). Patients with complete denervation (≤0 mmHg residual RNS response) showed significantly lower BP at follow-up.

Conclusions:

• Using RNS during RDN achieves clinically significant and sustained 24-h BP reduction with fewer antihypertensive drugs.
• RNS-induced BP changes correlate with 24-h BP changes, confirming RNS's role in assessing denervation efficacy.
• Complete denervation, as indicated by RNS, leads to superior BP control in patients with resistant hypertension.