title: An exploratory propensity score matched comparison of second-generation and first-generation baroreflex activation therapy systems.
abstract: Baroreflex activation therapy (BAT) is a device-based therapy for patients with treatment-resistant hypertension. In a randomized, controlled trial, the first-generation system significantly reduced blood pressure (BP) versus sham. Although an open-label validation study of the second-generation system demonstrated similar BP reductions, controlled data are not presently available. Therefore, this investigation compares results of first- and second-generation BAT systems. Two cohorts of first-generation BAT system patients were generated with propensity matching to compare against the validation group of 30 second-generation subjects. The first cohort was drawn from the first-generation randomized trial sham group and the second cohort from the active therapy group. Safety and efficacy were compared for the second-generation group relative to the first generation. At 6 months, second-generation BAT outperformed first-generation sham systolic BP reduction by 20 ± 28 mm Hg (mean ± standard deviation, P = .008), while BP reduction in first- and second-generation active groups was similar. At 12 months, efficacy was comparable between all three groups after the sham group had received 6 months of therapy; 47% of second-generation patients achieved goal systolic BP of 140 mm Hg or less after 12 months, comparable to 50% of patients at goal in the first-generation group (P > .999). Implant procedure time, system/procedural safety, and pulse generator longevity improved with the second-generation system. Propensity-matched cohort analysis of the first- and second-generation BAT systems suggests similar therapeutic benefit and superior BP reduction of the second-generation system relative to sham control. Implantation procedure duration and perioperative safety were improved with the second-generation device. These findings should be validated in a prospective randomized trial.
authors.affiliation: Clinic for Cardiology and Pneumology, German Center for Cardiovascular Research (DZHK), University of Göttingen, Göttingen, Germany. Electronic address: wachter@med.uni-goettingen.de.
authors.forename: Rolf
authors.initials: R
authors.lastname: Wachter
authors.affiliation: Department of Internal Medicine III, Heart Center, University of Cologne, Cologne, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Halbach
authors.affiliation: Department of Medicine, ASH Comprehensive Hypertension Center, Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, USA.
authors.forename: George L
authors.initials: GL
authors.lastname: Bakris
authors.affiliation: Division of Cardiology, Department of Internal Medicine, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Bisognano
authors.affiliation: Department of Nephrology and Hypertension, Medizinische Hochschule Hannover, Hannover, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Haller
authors.affiliation: Department of Nephrology and KfH Renal Unit, Hospital St. Georg, Leipzig, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Beige
authors.affiliation: Department of Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Abraham A
authors.initials: AA
authors.lastname: Kroon
authors.affiliation: Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Mitra K
authors.initials: MK
authors.lastname: Nadim
authors.affiliation: Department of Research, CVRx, Inc., Minneapolis, MN, USA.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Lovett
authors.affiliation: Department of Statistics, NAMSA, Inc., Minneapolis, MN, USA.
authors.forename: Jill E
authors.initials: JE
authors.lastname: Schafer
authors.affiliation: Department of Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Peter W
authors.initials: PW
authors.lastname: de Leeuw
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D017704:Baroreflex / Q000502:physiology; D001795:Blood Pressure Determination; D003329:Coronary Vasospasm / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D006973:Hypertension / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D057216:Propensity Score; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents
keywords: Autonomic nervous system; baroreflex; resistant hypertension; sham control