Renal denervation--so far so good.

82  © Japi • January 2014 • Vol. 62 Sir, R denervation (RD) is a catheter based method using radiofrequency ablation(RFA)for treatment of patients with resistant hypertension. T h e d a t a f r o m t w o c l i n i c a l trials(Symplicity HTN-1 and Symplicity HTN-2) has proven the safety and efficacy of RD for treating the patients with resistant hypertension.1,2 Symplicity HTN-1 was a non-randomised pilot trial involving 153 patients with mean office blood pressure(BP) of 176/98 ± 17/15 mm Hg taking the mean of 5 BP lowering medications. Bilateral RD with an average of 4 radiofrequency (RF) applications per artery showed a significant reduction in office BP values of 25/11 mm Hg at 6 months and 32/14 mm Hg at 2 years. These resul ts have been conf irmed with randomised control led Symplic i ty HTN-2 s tudy which inc luded 106 patients with primary end point being office BP 6 months after denervation. Over 84% of patients showed systolic BP reduction of ≥ 10 mm Hg. There were no procedure or device related serious complications. The enrolment for multi-centre, randomised single blind controlled Symplicity HTN-3 has already started with a primary end point of change in office BP after 6 months post denervation. The catheter based RD improves B P b y d e c r e a s i n g t h e e f f e r e n t sympathet ic s ignal ing to kidneys , increasing renal blood flow, natriuresis, lowering plasma renin activity and by decreasing renal afferent signaling and central sympathetic activation. The potential newer application of RD is in patients with obstructive sleep apnoea (OSA), metabolic syndrome and congestive heart failure (CHF) where CorrespondenCes