New data presented at the American Heart Association scientific sessions show that renal denervation significantly reduces blood pressure in patients with treatment-resistant hypertension.
Murray Esler, Baker IDI Heart and Diabetes Institute, Melbourne, Australia, presented results from the Symplicity HTN-2 Trial. The results were simultaneously published online in The Lancet.
Elser told delegates that “Activation of renal sympathetic nerves was key to the pathogenesis of essential hypertension.”
Investigators set out to assess effectiveness and safety of catheter-based renal denervation for reduction of blood pressure in patients with treatment-resistant hypertension.
Symplicity HTN-2 is a multicentre, prospective, randomised trial. Between June 9, 2009, and Jan 15, 2010, Elser et al randomised 106 patients who had a baseline systolic blood pressure of 160mmHg or more (≥150 mm Hg for patients with type 2 diabetes), despite taking three or more antihypertensive drugs in a one-to-one ratio to undergo renal denervation (n=52) with previous treatment or to maintain previous treatment alone (control group, n=54) at 24 participating centres. The primary effectiveness endpoint was change in supine office-based measurement of systolic blood pressure at six months. Primary analysis included all patients remaining in follow-up at six months.
Forty nine (94%) of 52 patients who underwent renal denervation and 51 (94%) of 54 controls were assessed for the primary endpoint at six months. Investigators found that office-based blood pressure measurements in the renal denervation group decreased by 32/12mmHg (+/- 23/1mmHg, baseline of 178/96mmHg; P <.0001) but did not differ from baseline values in the control group (change of 1/0mmHg [+/- 21/10], baseline of 178/97mmHg; P =.77 systolic and P =.83 diastolic).
Between-group differences in blood pressure at six months were 33/11 mm Hg (P <.0001).
At six months, 84% of the subjects receiving renal denervation had a decrease in systolic blood pressure of 10 mm Hg or more versus 35% of 51 controls (P <.0001).
There were no major procedure-related or device-related complications. One patient who had renal denervation had possible progression of an underlying atherosclerotic lesion, but required no treatment.
There were no changes in measured renal function with denervation, which suggests that the procedure itself and associated haemodynamic changes have no deleterious effects on the kidneys.