title: Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial.
abstract: BACKGROUND
  The SPACE trial is a multinational, prospective, randomised study to test the hypothesis that carotid artery stenting is not inferior to carotid endarterectomy for treating patients with severe symptomatic carotid artery stenosis. We did not prove non-inferiority of carotid artery stenting compared with carotid endarterectomy for the 30-day complication rate, and we now report the results at 2 years.
  
  
  METHODS
  Between March, 2001, and February, 2006, patients with symptomatic, severe (>or=70%) carotid artery stenosis were recruited to this non-inferiority trial and randomly assigned with a block randomisation design to have carotid artery angioplasty with stenting or carotid artery endarterectomy. 2-year endpoints include several clinical endpoints and the incidence of recurrent carotid stenosis of at least 70%. Clinical and vascular follow-up was done by a certified neurologist. Analyses were by intention to treat and per protocol. This trial is registered with ISRCTN, number 57874028.12.
  
  
  RESULTS
  1 214 patients were randomly assigned (613 were randomly assigned to carotid angioplasty with stenting and 601 were randomly assigned to carotid endarterectomy). In both the intention-to-treat and per-protocol analyses the Kaplan-Meier estimates of ipsilateral ischaemic strokes up to 2 years after the procedure and any periprocedural stroke or death do not differ between the carotid artery stenting and the carotid endarterectomy groups (intention to treat 9.5%vs 8.8%; hazard ratio (HR) 1.10, 95%CI 0.75 to 1.61; log-rank p=0.62; per protocol 9.4%vs 7.8%; HR 1.23, 95%CI 0.82 to 1.83; log-rank p=0.31). In both the intention-to-treat and per-protocol populations, recurrent stenosis of 70% or more is significantly more frequent in the carotid artery stenting group compared with the carotid endarterectomy group, with a life-table estimate of 10.7% versus 4.6% (p=0.0009) and 11.1% versus 4.6% (p=0.0007), respectively. Only two incidences of recurrent stenoses after carotid artery stenting led to neurological symptoms.
  
  
  CONCLUSIONS
  After 2 years' follow-up, the rate of recurrent ipsilateral ischaemic strokes reported in the SPACE trial is similar for both treatment groups. The incidence of recurrent carotid stenosis at 2 years, as defined by ultrasound, is significantly higher after carotid artery stenting. However, it cannot be excluded that the degree of in-stent stenosis is slightly overestimated by conventional ultrasound criteria.
authors.affiliation: Department of Vascular Surgery, Medical Center, Technical University of Munich, Germany.
authors.forename: Hans-Henning
authors.initials: HH
authors.lastname: Eckstein
authors.forename: Peter
authors.initials: P
authors.lastname: Ringleb
authors.forename: Jens-Rainer
authors.initials: JR
authors.lastname: Allenberg
authors.forename: Jürgen
authors.initials: J
authors.lastname: Berger
authors.forename: Gustav
authors.initials: G
authors.lastname: Fraedrich
authors.forename: Werner
authors.initials: W
authors.lastname: Hacke
authors.forename: Michael
authors.initials: M
authors.lastname: Hennerici
authors.forename: Robert
authors.initials: R
authors.lastname: Stingele
authors.forename: Jens
authors.initials: J
authors.lastname: Fiehler
authors.forename: Hermann
authors.initials: H
authors.lastname: Zeumer
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
mesh_terms: D000368:Aged; D017130:Angioplasty; D002339:Carotid Arteries / Q000601:surgery*; D016893:Carotid Stenosis / Q000150:complications* / Q000523:psychology / Q000601:surgery*; D016001:Confidence Intervals; D004311:Double-Blind Method; D016894:Endarterectomy, Carotid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013997:Time Factors