title: Transcatheter aortic valve implantation reduces sympathetic activity and normalizes arterial spontaneous baroreflex in patients with aortic stenosis.
abstract: OBJECTIVE
  This study sought to measure muscle sympathetic nerve activity (MSNA) in patients with aortic stenosis (AS) before and after transcatheter aortic valve implantation (TAVI) and to compare MSNA with that of control patients.
  
  
  BACKGROUND
  TAVI is an emerging therapeutic option in patients with severe AS at high risk of open heart surgery. Whether patients with AS have increased sympathetic activity remains to be established, and the effects of TAVI on the sympathetic nervous system are also unknown.
  
  
  METHODS
  We prospectively enrolled 14 patients with severe symptomatic AS treated by TAVI. Fourteen control patients matched for age, body mass index, and unscathed of AS were also included. All patients underwent MSNA and arterial baroreflex gain assessment at baseline and 1 week after TAVI for AS patients.
  
  
  RESULTS
  Patients with AS had lower blood pressure (BP) levels, a significant increase in MSNA (61.0 ± 1.7 burst/min vs. 55.4 ± 1.4 burst/min; p < 0.05), and a decrease in arterial baroreflex gain (2.13 ± 0.14% burst/mm Hg vs. 3.32 ± 0.19% burst/mm Hg; p < 0.01) compared with matched control patients. The TAVI procedures induced an increase in BP associated with a significant decrease in MSNA (from 61.0 ± 1.7 burst/min to 54.1 ± 1.0 burst/min; p < 0.01) and was associated with a significant increase in arterial baroreflex gain (from 2.13 ± 0.14% burst/mm Hg to 3.49 ± 0.33% burst/mm Hg; p < 0.01).
  
  
  CONCLUSIONS
  We report for the first time, through direct measurement of nerve activity, that patients with AS have increased sympathetic nervous system activity associated with a decrease in sympathetic baroreflex gain and that TAVI normalizes these parameters. This study provides evidence of a new beneficial effect of TAVI, namely, normalization of sympathetic nervous system hyperactivity.
authors.affiliation: Service de Cardiologie, Pôle Cardiovasculaire et Métabolique, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Dumonteil
authors.forename: Angelica
authors.initials: A
authors.lastname: Vaccaro
authors.forename: Fabien
authors.initials: F
authors.lastname: Despas
authors.forename: Marc
authors.initials: M
authors.lastname: Labrunee
authors.forename: Bertrand
authors.initials: B
authors.lastname: Marcheix
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lambert
authors.forename: Murray
authors.initials: M
authors.lastname: Esler
authors.forename: Didier
authors.initials: D
authors.lastname: Carrie
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Senard
authors.forename: Michel
authors.initials: M
authors.lastname: Galinier
authors.forename: Atul
authors.initials: A
authors.lastname: Pathak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D017704:Baroreflex; D001794:Blood Pressure; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation*; D011446:Prospective Studies; D012720:Severity of Illness Index; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome
keywords: AS; CHF; DBP; MAP; MSNA; SNS; TAVI; TF; aortic stenosis; arterial baroreflex; chronic heart failure; diastolic blood pressure; mean arterial blood pressure; muscle sympathetic nerve activity; sympathetic nervous system; transcatheter aortic valve implantation; transfemoral