title: Autonomic outcome is better after endarterectomy than after stenting in patients with asymptomatic carotid stenosis.
abstract: OBJECTIVE
  Carotid endarterectomy and stenting have comparable efficacy in stroke prevention in asymptomatic carotid stenosis. In patients with carotid stenosis, cardiac events have a more than threefold higher incidence than cerebrovascular events. Autonomic dysfunction predicts cardiovascular morbidity and mortality, and carotid stenosis interferes with baroreceptor and chemoreceptor function. We assessed the effect of elective carotid revascularization (endarterectomy vs stenting) on autonomic function as a major prognostic factor of cardiovascular health.
  
  
  METHODS
  In 42 patients with ≥70% asymptomatic extracranial carotid stenosis, autonomic function was determined by analysis of heart rate variability (total band power [TP], high frequency band power [HF], low-frequency band power [LF], very low frequency band power [VLF]), baroreflex sensitivity (αHF, αLF), respiratory chemoreflex sensitivity (central apnea-hypopnea index), and cardiac chemoreflex sensitivity (hyperoxic TP, HF, LF, and VLF ratios) before and 30 days after revascularization.
  
  
  RESULTS
  Patients with endarterectomy were older than patients with stenting (69 ± 7 vs 62 ± 7 years; P ≤ .008) but did not differ in gender distribution and preintervention autonomic function. Compared with stenting, postintervention heart rate variability was higher (ln TP, 6.7 [95% confidence interval (CI), 6.3-7.0] vs 6.1 [95% CI, 5.8-6.5; P ≤ .009]; ln HF, 4.5 [95% CI, 4.1-5.0] vs 4.0 [95% CI, 3.4-4.5; P ≤ .05]; ln VLF, 6.0 [95% CI, 5.7-6.4] vs 5.5 [95% CI, 5.2-5.9; P ≤ .02]); respiratory chemoreflex sensitivity (central apnea-hypopnea index, 5.5 [95% CI, 2.8-8.2] vs 10.0 [95% CI, 6.9-13.1; P ≤. 01]) and cardiac chemoreflex sensitivity (TP ratio, 1.2 [95% CI, 1.1-1.3] vs 1.0 [95% CI, 0.9-1.0; P ≤ .0001]; HF ratio, 1.4 [95% CI, 1.2-1.5] vs 0.9 [95% CI, 0.8-1.1; P ≤ .001]; LF ratio, 1.5 [95% CI, 1.3-1.6] vs 1.0 [95% CI, 0.8-1.1; P ≤ .0001]; VLF ratio, 1.2 [95% CI, 1.1-1.3) vs 1.0 [95% CI, 0.9-1.1; P ≤ .002]) were lower after endarterectomy. Postintervention baroreflex sensitivity did not differ after endarterectomy and stenting.
  
  
  CONCLUSIONS
  Autonomic function was better after endarterectomy than after stenting. Better autonomic function after endarterectomy was based on restoration of chemoreceptor but not baroreceptor function and may improve cardiovascular long-term outcome.
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany. Electronic address: sven.rupprecht@med.uni-jena.de.
authors.forename: Sven
authors.initials: S
authors.lastname: Rupprecht
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Finn
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Ehrhardt
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hoyer
authors.affiliation: Department of Neuroradiology, Jena University Hospital, Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mayer
authors.affiliation: Department of General, Visceral, and Vascular Surgery, Jena University Hospital, Jena, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Zanow
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Albrecht
authors.initials: A
authors.lastname: Guenther
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwab
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects / Q000295:instrumentation*; D058070:Asymptomatic Diseases; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex; D016893:Carotid Stenosis / Q000097:blood / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D002628:Chemoreceptor Cells / Q000378:metabolism; D017558:Elective Surgical Procedures; D016894:Endarterectomy, Carotid / Q000009:adverse effects; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome