title: Transcranial Doppler versus transthoracic echocardiography for the detection of patent foramen ovale in patients with cryptogenic cerebral ischemia: A systematic review and diagnostic test accuracy meta-analysis.
abstract: OBJECTIVE
  Patent foramen ovale (PFO) can be detected in up to 43% of patients with cryptogenic cerebral ischemia undergoing investigation with transesophageal echocardiography (TEE). The diagnostic value of transthoracic echocardiography (TTE) in the detection of PFO in patients with cryptogenic ischemic stroke or transient ischemic attack has not been compared with that of transcranial Doppler (TCD) using a comprehensive meta-analytical approach.
  
  
  METHODS
  We performed a systematic literature review to identify all prospective observational studies of patients with cryptogenic cerebral ischemia that provided both sensitivity and specificity measures of TTE, TCD, or both compared to the gold standard of TEE.
  
  
  RESULTS
  Our literature search identified 35 eligible studies including 3,067 patients. The pooled sensitivity and specificity for TCD was 96.1% (95% confidence interval [CI] = 93.0-97.8%) and 92.4% (95% CI = 85.5-96.1%), whereas the respective measures for TTE were 45.1% (95% CI = 30.8-60.3%) and 99.6% (95% CI = 96.5-99.9%). TTE was superior in terms of higher positive likelihood ratio values (LR+ = 106.61, 95% CI = 15.09-753.30 for TTE vs LR+ = 12.62, 95% CI = 6.52-24.43 for TCD; p = 0.043), whereas TCD demonstrated lower negative likelihood values (LR- = 0.04, 95% CI = 0.02-0.08) compared to TTE (LR- = 0.55, 95% CI = 0.42-0.72; p < 0.001). Finally, the area under the summary receiver operating curve (AUC) was significantly greater (p < 0.001) in TCD (AUC = 0.98, 95% CI = 0.97-0.99) compared to TTE studies (AUC = 0.86, 95% CI = 0.82-0.89).
  
  
  CONCLUSIONS
  TCD is more sensitive but less specific compared to TTE for the detection of PFO in patients with cryptogenic cerebral ischemia. The overall diagnostic yield of TCD appears to outweigh that of TTE.
authors.affiliation: Department of Neurology, University of Ioannina School of Medicine, Ioannina, Greece.|Second Department of Neurology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Aristeidis H
authors.initials: AH
authors.lastname: Katsanos
authors.affiliation: Department of Hygiene, Epidemiology, and Medical Statistics, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Theodora
authors.initials: T
authors.lastname: Psaltopoulou
authors.affiliation: Department of Hygiene, Epidemiology, and Medical Statistics, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Theodoros N
authors.initials: TN
authors.lastname: Sergentanis
authors.affiliation: Second Department of Cardiology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Frogoudaki
authors.affiliation: Second Department of Cardiology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Agathi-Rosa
authors.initials: AR
authors.lastname: Vrettou
authors.affiliation: Second Department of Cardiology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Ignatios
authors.initials: I
authors.lastname: Ikonomidis
authors.affiliation: Second Department of Cardiology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Paraskevaidis
authors.affiliation: Second Department of Cardiology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: John
authors.initials: J
authors.lastname: Parissis
authors.affiliation: Stroke Prevention and Atherosclerosis Research Centre, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.
authors.forename: Chrysa
authors.initials: C
authors.lastname: Bogiatzi
authors.affiliation: Second Department of Neurology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Zompola
authors.affiliation: Department of Neurology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: John
authors.initials: J
authors.lastname: Ellul
authors.affiliation: First Department of Neurology, Eginition Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Triantafyllou
authors.affiliation: Second Department of Neurology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Voumvourakis
authors.affiliation: Department of Neurology, University of Ioannina School of Medicine, Ioannina, Greece.
authors.forename: Athanassios P
authors.initials: AP
authors.lastname: Kyritsis
authors.affiliation: Department of Neurology, University of Ioannina School of Medicine, Ioannina, Greece.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Giannopoulos
authors.affiliation: Department of Neurology, University of Tennessee Health Sciences Center, Memphis, TN.|School of Nursing, Australian Catholic University, Sydney, Australia.
authors.forename: Anne W
authors.initials: AW
authors.lastname: Alexandrov
authors.affiliation: Department of Neurology, University of Tennessee Health Sciences Center, Memphis, TN.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Alexandrov
authors.affiliation: Second Department of Neurology, Attikon University Hospital, School of Medicine, University of Athens, Athens, Greece.|Department of Neurology, University of Tennessee Health Sciences Center, Memphis, TN.|International Clinical Research Center, Department of Neurology, St Anne's University Hospital Brno, Brno, Czech Republic.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsivgoulis
mesh_terms: D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D004452:Echocardiography / Q000592:standards*; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006801:Humans; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial / Q000592:standards*