Plasma endothelin-1 levels in patients with resistant hypertension: effects of renal sympathetic denervation.

INTRODUCTION: Resistant arterial hypertension (RHT) is defined as poor controlled blood pressure (BP) despite optimal doses of three or more antihypertensive agents, including a diuretic. In the development of RHT, hyperactivity of sympathetic (SNS) and renin-angiotensin-aldosterone (SRAA) systems are involved, and SNS is a potent stimulator of vasoactive endothelin-1 (ET-1) peptide. Renal sympathetic denervation (RSD) through disrupting renal afferent and efferent nerves attenuates SNS activity.

MATERIAL AND METHODS: We carried out pilot study investigating the effect of RSD on BP and plasma ET-1 levels in consecutive 9 RHT patients (7 male and 2 female, mean age of 56 ± 13.3).

RESULTS: After 12 months of the RSD, we observed a significant reduction of BP office, 24-h ambulatory BP monitoring (ABPM) (p < 0.05, respectively), and "non-dipping" pattern (from 55% to 35%) (p < 0.05). Moreover, RSD significantly decreased plasma ET-1 levels in both renal artery (at right from 21.8 ± 4.1 to 16.8 ± 2.9 pg/ml; p = 0.004; at left from 22.1 ± 3.7 to 18.9 ± 3.3 pg/ml; p = 0.02). We observed positive correlations between plasma renal arteries ET-1 levels and systolic BP values at ABPM [Global-SBP (r = 0.58; p < 0.01), Diurnal-SBP (r = 0.51; p < 0.03) and Nocturnal-SBP (r = 0.58; p < 0.01), respectively].

DISCUSSION: Our data confirmed the positive effects of RSD on BP values in patients with RHT, and showed a possible physio-pathological role of ET-1. KEY MESSAGES RSD is associated to a significant reduction of plasma ET-1 levels, representing an useful tool into reduction of BP in RHT patients.