title: Reference interval evaluation of high-sensitivity troponin T and N-terminal B-type natriuretic peptide in Vietnam and the US: The North South East West Trial.
abstract: BACKGROUND
  Reference intervals of high-sensitivity troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been determined from Western populations. No data are available regarding expected values in Asian populations.
  
  
  METHODS
  A total of 1157 age- and sex-matched healthy individuals (mean age, 41.2 years; 48.0% male) were prospectively enrolled from the US (n = 565) and Vietnam (n = 592). Blood samples were analyzed for hs-cTnT and NT-proBNP. Median values were determined for each country and compared in unadjusted analyses and in analyses adjusted for age, sex, body mass index, study site, race, and vital signs.
  
  
  RESULTS
  Median hs-cTnT concentrations were slightly higher for individuals from the US than for those from Vietnam, but both were below the limit of detection (3.7 vs 3.0 ng/L, respectively; P = 0.03). More US participants had an hs-cTnT concentration above the limit of detection (57.2% vs 47.3%; P = 0.001), but the 99th percentile concentration was slightly higher for Asians (US 15.1 vs Vietnam 19.0 ng/L). Concentrations for >98% of both populations were below the standard hs-cTnT 99th percentile of 14.0 ng/L (P = 0.54). Median NT-proBNP concentrations were slightly higher for US participants compared with Vietnamese participants (28 vs 16 ng/L, respectively; P < 0.001). Following adjustment, differences in concentrations of NT-proBNP between healthy US and Vietnamese populations remained significant, whereas for hs-cTnT the differences were no longer significant. Inclusion of hs-cTnT values down to the limit of blank did not change the result.
  
  
  CONCLUSIONS
  The differences in hs-cTnT and NT-proBNP between healthy individuals from the US and Vietnam are small. Previously derived reference intervals for both analytes may be applied in Asian populations.
authors.affiliation: Cardiology, Massachusetts General Hospital, Boston, MA;
authors.forename: Hanna K
authors.initials: HK
authors.lastname: Gaggin
authors.forename: Phuoc V
authors.initials: PV
authors.lastname: Dang
authors.forename: Loi D
authors.initials: LD
authors.lastname: Do
authors.forename: Christopher R
authors.initials: CR
authors.lastname: deFilippi
authors.forename: Robert H
authors.initials: RH
authors.lastname: Christenson
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Lewandrowski
authors.forename: Kent B
authors.initials: KB
authors.lastname: Lewandrowski
authors.forename: Binh Q
authors.initials: BQ
authors.lastname: Truong
authors.forename: Vinh Q
authors.initials: VQ
authors.lastname: Pham
authors.forename: Vu H
authors.initials: VH
authors.lastname: Vu
authors.forename: Truong V
authors.initials: TV
authors.lastname: Vu
authors.forename: Toan B
authors.initials: TB
authors.lastname: Nguyen
authors.forename: Arianna M
authors.initials: AM
authors.lastname: Belcher
authors.forename: Alexandra
authors.initials: A
authors.lastname: Femia
authors.forename: Cynthia
authors.initials: C
authors.lastname: Kelley
authors.forename: James L
authors.initials: JL
authors.lastname: Januzzi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000208:ethnology; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000208:ethnology; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012016:Reference Values; D012737:Sex Factors; D020107:Troponin T / Q000097:blood*; D014481:United States; D014744:Vietnam; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain