title: The value of core lab stress echocardiography interpretations: observations from the ISCHEMIA Trial.
abstract: BACKGROUND
  Stress echocardiography (SE) is dependent on subjective interpretations. As a prelude to the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial, potential sites were required to submit two SE, one with moderate or severe left ventricular (LV) myocardial ischemia and one with mild ischemia. We evaluated the concordance of site and core lab interpretations.
  
  
  METHODS
  Eighty-one SE were submitted from 41 international sites. Ischemia was classified by the number of new or worsening segmental LV wall motion abnormalities (WMA): none, mild (1 or 2) or moderate or severe (3 or more) by the sites and the core lab.
  
  
  RESULTS
  Core lab classified 6 SE as no ischemia, 35 mild and 40 moderate or greater. There was agreement between the site and core in 66 of 81 total cases (81%, weighted kappa coefficient [K] =0.635). Agreement was similar for SE type - 24 of 30 exercise (80%, K = 0.571) vs. 41 of 49 pharmacologic (84%, K = 0.685). The agreement between poor or fair image quality (27 of 36 cases, 75%, K = 0.492) was not as good as for the good or excellent image quality cases (39 of 45 cases, 87%, K = 0.755). Differences in concordance were noted for degree of ischemia with the majority of discordant interpretations (87%) occurring in patients with no or mild LV myocardial ischemia.
  
  
  CONCLUSIONS
  While site SE interpretations are largely concordant with core lab interpretations, this appears dependent on image quality and the extent of WMA. Thus core lab interpretations remain important in clinical trials where consistency of interpretation across a range of cases is critical.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01471522.
authors.affiliation: Cardiac Ultrasound Laboratory, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street Yawkey 5E, Boston, MA, 02114, USA. kataoaki@sd5.so-net.ne.jp.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Kataoka
authors.affiliation: Cardiac Ultrasound Laboratory, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street Yawkey 5E, Boston, MA, 02114, USA. marielle@crosbie.com.
authors.forename: Marielle
authors.initials: M
authors.lastname: Scherrer-Crosbie
authors.affiliation: Department of Cardiovascular Medicine, Division of Cardiology, National Heart and Lung Institute, Imperial College, Sydney Street, London, SW3 6NP, UK. roxysenior@cardiac-research.org.
authors.forename: Roxy
authors.initials: R
authors.lastname: Senior
authors.affiliation: Department of Medicine, Montreal Heart Institute, 5000 Belanger St, Montreal, QC H1T 1C8, Canada. g.gosselin@videotron.ca.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Gosselin
authors.affiliation: Department of Cardiology Research, CSSS du Sud de Lanaudiere, 911 Montee des Pionniers, Terrebonne, QC J6V 2H2, Canada. deniscphaneuf@hotmail.com.
authors.forename: Denis
authors.initials: D
authors.lastname: Phaneuf
authors.affiliation: Departamento de Cardiologia, Hospital Universitario La Paz, Paseo de la Castellana, 261, Madrid, 28046, Spain. gabrielaguzman.ny@hotmail.com.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Guzman
authors.affiliation: Cardiologia Riabilitativa e Preventiva, Ospedali Riuniti of Ancona, via Conca 71, Ancona, Marche, 60020, Italy. gp.perna@ospedaliriuniti.marche.it.
authors.forename: Gian
authors.initials: G
authors.lastname: Perna
authors.affiliation: Hospital de Especialidades, Centro Medico Nacional 'La Raza', CRC IMSS, Gabriel Mancera 222 Col. del Valle, Benito Juarez, DF, 3100, Mexico. jorgeep@unam.mx.
authors.forename: Alfonso
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authors.lastname: Lara
authors.affiliation: Interventional Cardiology, University Clinic of Cardiology, Vodnjanska 17, Skopje, Macedonia. skedev@mt.net.mk.
authors.forename: Sasko
authors.initials: S
authors.lastname: Kedev
authors.affiliation: Department of Clinical Cardiology and Heart Failure, Policlinico de Monza, Via Amati 111, Monza, MB, 20900, Italy. andreamortara@libero.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mortara
authors.affiliation: Division of Cardiology, Internal Medicine, Albany Medical College and Stratton VA Medical Center, 47 New Scotland Ave. MC 44, Albany, NY, 12208, USA. el-hajm@mail.amc.edu.
authors.forename: Mohammad
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authors.lastname: El-Hajjar
authors.affiliation: Department of Medicine, Division of Cardiology, Emory University School of Medicine, 1462 Clifton Road, Atlanta, GA, 30322, USA. lshaw3@emory.edu.
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
authors.affiliation: Department of Medicine, Division of Cardiology, New York University Langone Medical Center, 423 East 23rd Street 15150 N, New York, NY, 10010, USA. Harmony.Reynolds@nyumc.org.
authors.forename: Harmony R
authors.initials: HR
authors.lastname: Reynolds
authors.affiliation: Cardiac Ultrasound Laboratory, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street Yawkey 5E, Boston, MA, 02114, USA. MHPICARD@mgh.harvard.edu.
authors.forename: Michael H
authors.initials: MH
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mesh_terms: D000368:Aged; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology