The sympathetic nervous system is implicated in most form of hypertension. In resistant hypertension, transcatheter renal denervation (RDN) has been proposed as an adjunctive therapy to antihypertensive drugs at maximum tolerated doses. The results on blood pressure (BP) reduction have been the source of debate. Few studies have explored the effect on renal hemodynamics and tubular sodium handling. The objective was to assess these two parameters before RND and after 1 and 12 months.Design and method:
Patients with confirmed resistant hypertension and no contraindications for RDN could be included in the study. Systemic hemodynamic, renal hemodynamic using inulin and PAH clearances, sodium and endogenous lithium clearances (a marker of proximal sodium reabsorption), hormones were measured in standardized condition before RDN and after 1 and 12 months. Variables were compared with an analysis of variance.Results:
13 patients were included in the study. Mean age was 56.1 ± 9.9 years, body mass index was 30.9 ± 9.9 Kg/m2. Mean number of ablation points was 4.7 ± 1.2 points on the left artery and 5.0 ± 1.6 points on the right artery. The following table displays the systemic and renal hemodynamics, the sodium tubular handling and the hormonal profile before RDN and after 1 and 12 months.Results:
BP and heart rate remained constant while glomerular filtration rate and filtration fraction decreased. Proximal sodium reabsorption, assed by lithium clearances, increased with time. Plasma renin activity tended to increase which could not be explained by the use of diurectics which was similar before and 12 months after RDN.Conclusions:
One year after renal denervation, renal hemodynamics and tubular sodium handling seem to be altered with increased filtration fraction and proximal sodium reabsorption. The long term effects of these changes on renal function and blood pressure need to be assed in long term follow-up studies.