title: Catheter-based renal sympathetic denervation for resistant hypertension: a multicentre safety and proof-of-principle cohort study.
abstract: BACKGROUND
  Renal sympathetic hyperactivity is associated with hypertension and its progression, chronic kidney disease, and heart failure. We did a proof-of-principle trial of therapeutic renal sympathetic denervation in patients with resistant hypertension (ie, systolic blood pressure >/=160 mm Hg on three or more antihypertensive medications, including a diuretic) to assess safety and blood-pressure reduction effectiveness.
  
  
  METHODS
  We enrolled 50 patients at five Australian and European centres; 5 patients were excluded for anatomical reasons (mainly on the basis of dual renal artery systems). Patients received percutaneous radiofrequency catheter-based treatment between June, 2007, and November, 2008, with subsequent follow-up to 1 year. We assessed the effectiveness of renal sympathetic denervation with renal noradrenaline spillover in a subgroup of patients. Primary endpoints were office blood pressure and safety data before and at 1, 3, 6, 9, and 12 months after procedure. Renal angiography was done before, immediately after, and 14-30 days after procedure, and magnetic resonance angiogram 6 months after procedure. We assessed blood-pressure lowering effectiveness by repeated measures ANOVA. This study is registered in Australia and Europe with ClinicalTrials.gov, numbers NCT 00483808 and NCT 00664638.
  
  
  RESULTS
  In treated patients, baseline mean office blood pressure was 177/101 mm Hg (SD 20/15), (mean 4.7 antihypertensive medications); estimated glomerular filtration rate was 81 mL/min/1.73m(2) (SD 23); and mean reduction in renal noradrenaline spillover was 47% (95% CI 28-65%). Office blood pressures after procedure were reduced by -14/-10, -21/-10, -22/-11, -24/-11, and -27/-17 mm Hg at 1, 3, 6, 9, and 12 months, respectively. In the five non-treated patients, mean rise in office blood pressure was +3/-2, +2/+3, +14/+9, and +26/+17 mm Hg at 1, 3, 6, and 9 months, respectively. One intraprocedural renal artery dissection occurred before radiofrequency energy delivery, without further sequelae. There were no other renovascular complications.
  
  
  CONCLUSIONS
  Catheter-based renal denervation causes substantial and sustained blood-pressure reduction, without serious adverse events, in patients with resistant hypertension. Prospective randomised clinical trials are needed to investigate the usefulness of this procedure in the management of this condition.
authors.affiliation: Centre of Cardiovascular Research and Education in Therapeutics, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
authors.forename: Henry
authors.initials: H
authors.lastname: Krum
authors.forename: Markus
authors.initials: M
authors.lastname: Schlaich
authors.forename: Rob
authors.initials: R
authors.lastname: Whitbourn
authors.forename: Paul A
authors.initials: PA
authors.lastname: Sobotka
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sadowski
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bartus
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Kapelak
authors.forename: Anthony
authors.initials: A
authors.lastname: Walton
authors.forename: Horst
authors.initials: H
authors.lastname: Sievert
authors.forename: Suku
authors.initials: S
authors.lastname: Thambar
authors.forename: William T
authors.initials: WT
authors.lastname: Abraham
authors.forename: Murray
authors.initials: M
authors.lastname: Esler