title: Degree of contralateral carotid stenosis improves preoperative risk stratification of patients with asymptomatic ipsilateral carotid stenosis.
abstract: OBJECTIVE
  The benefit of carotid surgery in asymptomatic patients with high-grade internal carotid artery stenosis (ICAS) is subject of intense debate, and thus improved preoperative risk stratification is mandatory. This study aimed to investigate the predictive value of contralateral ICAS (cl-ICAS) for the preoperative clinical presentation of patients with ipsilateral ICAS (primary outcome).
  
  
  METHODS
  This study was a post hoc analysis of a prospective cohort comprising 485 consecutive patients undergoing carotid endarterectomy for high-grade ICAS. Patients were classified by their clinical presentation, ie, asymptomatic (n = 213) or symptomatic (within 6 months of surgery; n = 272, comprising both transient ischemic attack [TIA; n = 163] and stroke [n = 109]). We investigated the association of cl-ICAS with the primary outcome in adjusted regression models.
  
  
  RESULTS
  Mean ipsilateral degrees of ICAS were similar in both groups (84% ± 10% vs 84% ± 11%; P = .92), whereas contralateral degrees were significantly higher in the symptomatic group (29% ± 34% vs 38% ± 39%; P = .008). After multivariable regression analysis, cl-ICAS >60% conferred a three times higher preoperative stroke risk (odds ratio, 3.31; 95% confidence interval, 1.98-5.54; P < .001). Inclusion of cl-ICAS significantly improved (P = .001) ipsilateral combined TIA and stroke risk prediction based on established risk factors (area under the curve, 0.66; 95% confidence interval, 0.60-0.72; P < .001).
  
  
  CONCLUSIONS
  Our study identifies a high contralateral degree of ICAS as an independent predictor of preoperative ipsilateral TIA and stroke in patients with ipsilateral high-grade ICAS. Therefore, such patients might rather benefit from elective carotid surgery and intensive postoperative medical care.
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Jelena
authors.initials: J
authors.lastname: Basic
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Afshin
authors.initials: A
authors.lastname: Assadian
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Johann
authors.initials: J
authors.lastname: Strassegger
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Senekowitsch
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Wickenhauser
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Koulas
authors.affiliation: Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Waldhör
authors.affiliation: Department of Vascular and Endovascular Surgery, Wilhelminenspital, Vienna, Austria. Electronic address: nduschek@me.com.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Duschek
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D019540:Area Under Curve; D058070:Asymptomatic Diseases; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery*; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery*; D016009:Chi-Square Distribution; D017558:Elective Surgical Procedures; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex