Renal sympathetic denervation significantly reduces blood pressure but not cause orthostatic dysregulation in patients with resistant hypertension

Abstract

Backround: Patients (pts.) with resistant hypertension have been characterized by increased sympathetic nerve activity when compared to normotensive subjects. Before the introduction of modern antihypertensive drugs patients have been treated with surgical lumbal sympathectomy. However, this procedure was linked with severe side effects such as severe orthostatic dysregulation. Recently, catheter-based bilateral renal denervation (RDN) of sympathetic nerve fibres has been shown to significantly lower blood pressure (BP). However, the effect of RDN on orthostatic blood pressure regulation is not known. Methods: 9 pts. were selected according to the SIMPLICITY criteria and treated with RDN. Follow-up included baseline values and measurements at 3 and 6 months. Office BP was measured with OmeronTM. A Schellong test was performed at baseline, 3 and 6 month after RDN. After being in relaxed supine position for 10 min. BP and heart rate (HR) was measured every 2 minutes. BP and HR were then measured in an upright position over ten min. and after returning into a supine positon. Results: The baseline mean office SBP/DBP was 176/89 mmHg (SEM 5/6 mmHg), after 6 month 141/80 mmHg (SEM 6/4). Pts. were treated with 5.3 antihypertensives mean. As shown by the Schellong test there was no significant difference in the overall orthostatic regulation of the BP, the level of BP was lower 6 month after RDN as compared to baseline. HR did not differ between the two groups. ![Figure][1] Figure 1. SBP at 3 and 6 month Conclusion: (i) In patients with resistant hypertension RDN resulted in a significant blood pressure reduction after 3 and 6 month. (ii) No orthostatic dysregulation or syncope were be identified after RDN using the Schellong-test, indicating that RDN has no effect on venous tone and venous capacity when tilting into an upright position. [1]: pending:yes