Renal sympathetic nerve activity after catheter-based renal denervation

• Published in: EJNMMI research 2018-01, Vol.8 (1), p.8-11, Article 8
• Main Authors: Dobrowolski, Linn C., Eeftinck Schattenkerk, Daan W., Krediet, C. T. Paul, Van Brussel, Peter M., Vogt, Liffert, Bemelman, Frederike J., Reekers, Jim A., Van Den Born, Bert-Jan H., Verberne, Hein J.
• Format: Article
• Language: English
• Subjects: Ablation; Blood pressure; Cardiac Imaging; Catheters; Hypertension; Imaging; Kidneys; Mathematical analysis; Medicine; Medicine & Public Health; Muscles; Nuclear Medicine; Oncology; Original Research; Orthopedics; Radiology; Radionuclide imaging; Renal catheter ablation; Renal nerves; Sympathetic nerve activity
• ISSN: 2191-219X; 2191-219X
• DOI: 10.1186/s13550-018-0360-1

Background Catheter-based renal sympathetic denervation (RDN) has been considered a potential treatment for therapy resistant hypertension (RHT). However, in a randomized placebo-controlled trial, RDN did not lead to a substantial blood pressure (BP) reduction. We hypothesized that variation in the reported RDN efficacy might be explained by incomplete nerve disruption as assessed by renal 123 I– meta -iodobenzylguanidine ( 123 I– m IBG) scintigraphy. Methods In 21 RHT patients (median age 60 years), we performed 123 I– m IBG scintigraphy before and 6 weeks after RDN. Additionally, we assessed changes in BP (24 h day, night, and average), plasma- and urinary-catecholamines and plasma renin activity (PRA) before and after RDN. Planar scintigraphy was performed at 15 min and 4 h after 123 I– m IBG administration. The ratio of the mean renal (specific) counts vs. muscle (non-specific) counts represented 123 I– m IBG uptake. Renal 123 I– m IBG washout was calculated between 15 min and 4 h. Results After RDN office-based systolic BP decreased from 172 to 153 mmHg ( p  = 0.036), while diastolic office BP ( p  = 0.531), mean 24 h systolic and diastolic BP ( p  = 0.602, p  = 0.369, respectively), PRA ( p  = 0.409) and plasma catecholamines ( p  = 0.324) did not significantly change post-RDN. Following RDN, 123 I– m IBG renal uptake at 15 min was 3.47 (IQR 2.26–5.53) compared to 3.08 (IQR 2.79–4.95) before RDN ( p  = 0.289). Renal 123 I– m IBG washout did not change post-RDN ( p  = 0.230). In addition, there was no significant correlation between the number of denervations and the renal 123 I– m IBG parameters. Conclusions No changes were observed in renal 123 I– m IBG uptake or washout at 6 weeks post-RDN. These observations support incomplete renal denervation as a possible explanation for the lack of RDN efficacy.