Effect of renal denervation on catecholamines and the renin-angiotensin-aldosterone system

Introduction: The effect of renal sympathetic denervation (RDN) on neurohormonal responses is largely unknown. We aimed to assess the effect of RDN on the renin-angiotensin-aldosterone system (RAAS) and endogenous catecholamines. Methods: A total of 60 patients with hypertension underwent RDN and remained on a stable antihypertensive drug regimen. Samples for plasma aldosterone, plasma renin and urine (nor)metanephrine were collected at baseline and at 6 months post procedure. Ambulatory blood pressure (BP) recordings were obtained at baseline and at 6 months post procedure. Results: Mean age was 64 +/- 9 years, and 30/60 patients were male. At 6 months, average daytime systolic and diastolic ambulatory BP decreased by 10 and 6 mmHg, respectively (p<0.001). No significant change was observed in plasma aldosterone (median=248.0 pmol/L (interquartile range (IQR) 113.3-369.5 pmol/L) vs. median=233.0 pmol/L (IQR 110.3-360.8 pmol/L);p=0.66); renin (median=19.5 mu IU/mL (IQR 6.8-119.5 mu IU/mL) vs. median=14.3 mu IU/mL (IQR 7.2-58.0 mu IU/mL);p=0.32), urine metanephrine (median=0.46 mu mol/L (IQR 0.24-0.77 mu mol/L) vs. median=0.46 mu mol/L (IQR 0.22-0.88 mu mol/L);p=0.75) and normetanephrine (median=1.41 mu mol/L (IQR 0.93-2.00 mu mol/L vs. median =1.56 (IQR 0.74-2.50 mu mol/L);p=0.58) between baseline and 6 months, respectively. No correlation was found between the decrease in mean systolic daytime BP and changes in RAAS hormones or endogenous catecholamines. Conclusion: Despite significant reductions in ambulatory BP, RDN did not result in a significant change in endogenous catecholamines or in RAAS hormones at 6 months.