title: High-sensitivity cardiac troponin T for earlier diagnosis of acute myocardial infarction in patients with initially negative troponin T test--comparison between cardiac markers.
abstract: OBJECTIVE
  An early diagnosis is essential for therapeutic decision and risk stratification in patients with suspected acute myocardial infarction (AMI). We analyzed and compared the diagnostic value of high-sensitivity troponin T (hs-TnT) and other cardiac markers in patients with an initially negative troponin T test at presentation.
  
  
  METHODS
  The present study was a prospective, multicenter study including five participating emergency cardiovascular tertiary centers in Japan. From November 2009 through January 2011, patients with suspected AMI at the emergency room with an initial troponin T (c-TnT) test <100 ng/L were enrolled.
  
  
  RESULTS
  A total of 85 patients were prospectively assigned from five participating emergency cardiovascular tertiary centers in Japan. The median time from the onset of chest pain to the T0 sampling was 165 min [IQR 120-180]. The final diagnoses according to the recent universal definition and other standard cut-off values were AMI in 47, unstable angina in 12, and non AMI in 38 patients. The overall ROC-AUC value of hs-TnT, c-TnT, creatine kinase MB, and heart-type fatty acid-binding protein were 0.810, 0.716, 0.782, and 0.880, respectively. The diagnostic sensitivity and negative predictive value of hs-TnT were both 100% for the patients admitted more than 120 min from the onset, however the specificity was limited for the whole time-windows (71%). The absolute value change of the hs-TnT from T0 to T3 sampling 3h later improved the ROC-AUC up to 0.972 and the specificity was 92% at 22 ng/L (ROC-optimized cut-off) and 100% at 105 ng/L (rule-in cut-off).
  
  
  CONCLUSIONS
  The hs-TnT displayed 100% sensitivity and negative predictive value for the patients admitted more than 120 min from the onset, however the specificity was limited. The absolute change from T0 to T3 (22 ng/L) improved the total diagnostic performance.
authors.affiliation: Division of Intensive Care Unit, Nippon Medical School Chiba-Hokusoh Hospital, Chiba, Japan.
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Kitamura
authors.affiliation: Division of Intensive Care Unit, Nippon Medical School Chiba-Hokusoh Hospital, Chiba, Japan.
authors.forename: Noritake
authors.initials: N
authors.lastname: Hata
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Tadateru
authors.initials: T
authors.lastname: Takayama
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
authors.affiliation: Department of Cardiology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Ogawa
authors.affiliation: Department of Cardiology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamashina
authors.affiliation: Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Mera
authors.affiliation: Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yoshino
authors.affiliation: Third Department of Internal Medicine, Teikyo University Chiba Medical Center, Chiba, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Nakamura
authors.affiliation: Cardiovascular Center, Nippon Medical School Chiba-Hokusoh Hospital, Chiba, Japan. Electronic address: y-seino@nms.ac.jp.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Seino
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Acute coronary syndrome; Biomarker; Heart-type fatty acid-binding protein; High-sensitivity troponin T