Abstract 17567: Renal Denervation Therapy in Patients with Resistant Hypertension is Associated by Enhanced Urinary Sodium Excretion
Backround: Hypertensive patients (Pts) are characterized by increased sympathetic nerve activity (SNA) when compared with normotensive subjects. There is evidence that SNA results in increased renin secretion, renal tubular sodium reabsorption, and decreased renal blood flow. Recently, catheter-based bilateral renal denervation (RDN) has been shown to significantly lower blood pressure (BP). However, the pathophysiological mechanisms of RDN induced BP reduction is unknown.
Methods: 20 Pts were selected according to the SIMPLICITY criteria (SBP >160mmHg, diabetics >150mmHg in spite of ≥3 antihypertensives, GFR >45ml/min). 15 Pts treated with RDN (SIMPLICITY catheter®) and 5 Pts (Ctr) treated only medically. Medication and salt intake did not change during observation. Follow-up included baseline values and measurements at 3 and 6 months. Office BP was measured with OmeronTM. We determined 24-hour urine sodium (UNa) excretion and to exclude renal damage, the fractional sodium excretion (FENa) and urine albumin.
Results: The baseline mean office SBP/DBP was 176/93 mmHg (SEM ±3/3 mmHg), and 169/90 mmHg (SEM ±1/5 mmHg). In average, patients were treated with 5.2 antihypertensives. After RDN the SBP/DBP decreased by -30/-13 mmHg at 6 month (p<0.01 vs. baseline), whereas there was no significant change in the control group. Table 1 shows the effect of RDN on relative UNa excretion and FENa. Serum creatinine and urinary excretion of albumin (not shown) was unchanged over time in both groups.
Conclusion: (i) In Pts with resistant hypertension RDN resulted in a significant BP reduction (ii) BP reducing effects of RDN may be related to enhanced natriuresis, thereby leading to a new balance between salt intake and salt excretion (iii) The enhanced natriuresis is not due to tubular damage as assessed by FENa and normal excretion of urinary proteins, suggesting that RDN is a save procedure.
- © 2012 by American Heart Association, Inc.