Abstract 17516: Does Renal Denervation Impact on Tissue Na+ Content in Treatment Resistant Hypertension?
Objective: Renal denervation (RDN) was shown to be effective in reducing blood pressure (BP) in treatment-resistant hypertension. The precise mechanism how RDN exerts its BP-lowering effects are not yet fully understood. It is widely accepted that sodium (Na+) plays a crucial role in hypertension. However, there is increasing evidence of osmotically inactive Na+ storage. Hence, we investigated the impact of RDN on tissue Na+ content.
Design and methods: In a pilot study 26 male and 4 female patients with treatment-resistant hypertension (office BP≥140/90 mmHg and diagnosis confirmed by 24-h ABPM) underwent RDN. Tissue Na+ content was assessed non-invasively with 3.0T magnetic resonance imaging (MRI) (Magnetom Tim Trio, Siemens Healthcare, Erlangen, Germany) before (day-1) and 6 months after RD.
Results: There was a significant fall in average 24-h ABPM (systolic: 158±15 vs. 148±13mmHg, p<0.01 and diastolic: 86±13 vs. 81±8mmHg, p<0.01) 6 months after RD. In contrast, tissue Na+ content of the muscle (21.4±5.1 vs. 21.6±4.3 mmol/L, p=ns) and skin (25.9±7.8 vs. 26.8±7.6 mmol/L, p=ns) did not change after RDN. This finding was not biased by changes in muscle and skin water content, which did not change after RDN. After stratifying patients according to gender, there was a significant difference in tissue Na+ content of the skin (male: 27.0±7.5 vs. female: 19.3±4.9 mmol/L, p=0.019). However, change of tissue Na+ content of the skin due to RDN did not differ between men and women. There were no changes in serum sodium content and body weight.
Conclusion: Although RDN resulted in a substantial reduction of BP, tissue Na+ content of the muscle and skin was not mobilized and reduced. These data indicate the BP reduction after RDN is unrelated to sodium homeostasis.
- © 2013 by American Heart Association, Inc.