title: Impaired cardiac baroreflex sensitivity predicts response to renal sympathetic denervation in patients with resistant hypertension.
abstract: OBJECTIVE
  This study sought to evaluate cardiac baroreflex sensitivity (BRS) as a predictor of response to renal sympathetic denervation (RDN).
  
  
  BACKGROUND
  Catheter-based RDN is a novel treatment option for patients with resistant arterial hypertension. It is assumed that RDN reduces efferent renal and central sympathetic activity.
  
  
  METHODS
  Fifty patients (age 60.3 ± 13.8 years [mean ± SD mean systolic blood pressure (BP) on ambulatory blood pressure monitoring (ABPM) 157 ± 22 mm Hg, despite medication with 5.4 ± 1.4 antihypertensive drugs) underwent RDN. Prior to RDN, a 30-min recording of continuous arterial BP (Finapres; TNO-TPD Biomedical Instrumentation, Amsterdam, the Netherlands) and high-resolution electrocardiography (1.6 kHz in orthogonal XYZ leads) was performed in all patients under standardized conditions. Cardiac BRS was assessed by phase-rectified signal averaging (BRSPRSA) according to previously published technologies. Response to RDN was defined as a reduction of mean systolic BP on ABPM by 10 mm Hg or more at 6 months after RDN.
  
  
  RESULTS
  Six months after RDN, mean systolic BP on ABPM was significantly reduced from 157 ± 22 mm Hg to 149 ± 20 mm Hg (p = 0.003). Twenty-six of the 50 patients (52%) were classified as responders. BRSPRSA was significantly lower in responders than nonresponders (0.16 ± 0.75 ms/mm Hg vs. 1.54 ± 1.73 ms/mm Hg; p < 0.001). Receiver-operator characteristics analysis revealed an area under the curve for prediction of response to RDN by BRSPRSA of 81.2% (95% confidence interval: 70.0% to 90.1%; p < 0.001). On multivariable logistic regression analysis, reduced BRSPRSA was the strongest predictor of response to RDN, which was independent of all other variables tested.
  
  
  CONCLUSIONS
  Impaired cardiac BRS identifies patients with resistant hypertension who respond to RDN.
authors: Abteilung Innere Medizin III, Department of Cardiology, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
authors: Christine S
authors: CS
authors: Zuern
authors: Christian
authors: C
authors: Eick
authors: Konstantinos D
authors: KD
authors: Rizas
authors: Sarah
authors: S
authors: Bauer
authors: Harald
authors: H
authors: Langer
authors: Meinrad
authors: M
authors: Gawaz
authors: Axel
authors: A
authors: Bauer
mesh_terms: D000368:Aged; D017704:Baroreflex; D018660:Blood Pressure Monitoring, Ambulatory; D017115:Catheter Ablation; D003714:Denervation / Q000379:methods*; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D006973:Hypertension; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012077:Renal Artery / Q000294:innervation / Q000601:surgery*
keywords: ABPM; AIC; AUC; Akaike information criterion; BMI; BP; BRS; BRS(PRSA); BRS(SEQ); CI; IDI; MSNA; PRSA; RDN; ROC; ambulatory blood pressure monitoring; area under the curve; arterial hypertension; baroreflex sensitivity; blood pressure; body mass index; cardiac baroreflex sensitivity assessed by phase-rectified signal averaging; cardiac baroreflex sensitivity assessed by the sequence method; confidence interval; integrated discrimination improvement; muscle sympathetic nerve activity; phase-rectified signal averaging; receiver-operator characteristic; renal sympathetic denervation; sympathetic nervous system