Objectives: 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.
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.
Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.