title: A clinical rule (sex, contralateral occlusion, age, and restenosis) to select patients for stenting versus carotid endarterectomy: systematic review of observational studies with validation in randomized trials.
abstract: OBJECTIVE
  Compared with carotid endarterectomy (CEA), carotid angioplasty and stenting (CAS) is associated with a higher risk of procedural stroke or death especially in patients with symptomatic stenosis. However, after the perioperative period, risk is similar with both treatments, suggesting that CAS could be an acceptable option in selected patients.
  
  
  METHODS
  We performed systematic reviews of observational studies of procedural risks of CEA or CAS and extracted data on 9 predefined risk factors (age, contralateral carotid occlusion, coronary artery disease, diabetes mellitus, sex, hypertension, peripheral artery disease, and type and side of stenosis). We calculated pooled relative risks of procedural stroke or death. Factors with differential effects on risk of CAS versus CEA were identified by interaction tests and used to derive a rule. The rule was tested using individual patient data from randomized trials of CAS versus CEA from the Carotid Stenting Trialists' Collaboration (CSTC).
  
  
  RESULTS
  We identified 170 studies. The effects of sex, contralateral occlusion, age, and restenosis (SCAR) on the procedural risk of stroke or death differed. Patients with contralateral occlusion or restenosis and women<75 years were at relatively low risk for CAS (SCAR negative), with all others being high risk (SCAR positive). Among the 3049 patients in the CSTC validation, 694 (23%) patients were SCAR negative. The pooled RR of procedural stroke and death with CAS versus CEA was 0.93 (0.49-1.77; P=0.83) in SCAR-negative and 2.41 (1.68-3.45; P<0.0001) in SCAR-positive patients (P [interaction]=0.05).
  
  
  CONCLUSIONS
  The SCAR rule is potentially useful to identify patients in whom CAS has a similar risk of perioperative stroke or death to CEA.
authors.affiliation: From the Université Paris Descartes, Sorbonne Paris Cité, INSERM UMR S894, Service de Neurologie, Hôpital Sainte-Anne, Paris, France (E.T., G.M., J.-L.M.); Université de Caen Basse Normandie, INSERM UMR-S U919, Service de Neurologie, CHU Côte de Nacre, Caen, France (E.T.); French Cochrane Centre, Université Paris Descartes, Sorbonne Paris Cité, INSERM U738, Assistance Publique-Hôpitaux de Paris, Hôpital Hôtel-Dieu, Centre d'Epidémiologie Clinique, Paris, France (L.T.); Neurology Department, Hospital Santo António, Centro Hospitalar do Porto, Largo Professor Abel Salazar, Porto, Portugal (R.F.); Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand (K.R.); Department of Neurology and Stroke Unit, University Hospital Basel, Switzerland (L.H.B.); Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, Queen Square, London, UK (L.H.B., M.M.B.); Department of Neurology, University Hospital Heidelberg, Im Neuenheimer Feld 400, Heidelberg, Germany (P.A.R.); and Stroke Prevention Research Unit, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, UK (P.M.R.).
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Touzé
authors.forename: Ludovic
authors.initials: L
authors.lastname: Trinquart
authors.forename: Rui
authors.initials: R
authors.lastname: Felgueiras
authors.forename: Kittipan
authors.initials: K
authors.lastname: Rerkasem
authors.forename: Leo H
authors.initials: LH
authors.lastname: Bonati
authors.forename: Gayané
authors.initials: G
authors.lastname: Meliksetyan
authors.forename: Peter A
authors.initials: PA
authors.lastname: Ringleb
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mas
authors.forename: Martin M
authors.initials: MM
authors.lastname: Brown
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rothwell
mesh_terms: D000367:Age Factors; D000368:Aged; D003657:Decision Making; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D018579:Patient Selection; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D015607:Stents; D020521:Stroke / Q000601:surgery*; D016896:Treatment Outcome
keywords: atherosclerosis; carotid endarterectomy; carotid stenosis; carotid stenting; meta-analysis; prevention; systematic review