title: [Usefulness of high sensitivity troponin T assay in detecting acute allograft rejection after heart transplantation].
abstract: OBJECTIVE
  Detection of acute allograft rejection in heart transplant recipients by noninvasive methods is a challenge in the management of these patients. In this study, the usefulness of a new highly sensitive method for the measurement of troponin T is evaluated.
  
  
  METHODS
  We designed a case-crossover study, in which each patient served as his or her own control, by selecting samples from treated acute rejection episodes (29 cases) and samples obtained immediately before and/or after rejection (38 controls). The highly sensitive troponin T was measured by a new pre-commercial test (Elecsys Troponin T HS).
  
  
  RESULTS
  In all samples, highly sensitive troponin T was detectable, with a median of 0.068 ng/L (IQR, 0.030-0.300 ng/L). The levels correlated with right atrial pressure (r=0.37; P=.002), N-terminal pro-brain natriuretic peptide concentration (r=0.67; P<.001), and time since transplantation (r=-0.81; P<.001). The highly sensitive troponin T concentrations were higher in patients with rejection (0.155 ng/mL vs 0.047 ng/mL; P=.006). In the receiver operating characteristic analysis, the area under the curve was 0.67 (95% confidence interval, 0.53-0.77) and the best cutoff was 0.035 ng/mL, which was associated with rejection (odds ratio=3.7; 95% confidence interval, 1.2-11.9; P=.02). By restricting the analysis to the first 2 months, the area under the curve increased to 0.86 (95% confidence interval 0.66-0.97), with an optimal cutoff of 1.10 ng/mL (S=58% [28%-85%]; E=100% [74%-100%]).
  
  
  CONCLUSIONS
  Troponin T was detectable in all samples when a new highly sensitive assay was used, and at higher concentrations in the presence of acute rejection; however, the usefulness of this test in patient management is limited to support for clinical or histological suspicion of rejection, especially in the early post-transplant period.
authors.affiliation: Unidad de Insuficiencia Cardiaca y Trasplante Cardiaco, Servicio de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, España.
authors.forename: Carmen
authors.initials: C
authors.lastname: Muñoz-Esparza
authors.forename: Iris P
authors.initials: IP
authors.lastname: Garrido
authors.forename: Rosa
authors.initials: R
authors.lastname: Blanco
authors.forename: Teresa
authors.initials: T
authors.lastname: Casas
authors.forename: Cristina
authors.initials: C
authors.lastname: González-Cánovas
authors.forename: Francisco
authors.initials: F
authors.lastname: Pastor-Pérez
authors.forename: Pablo
authors.initials: P
authors.lastname: Peñafiel
authors.forename: Alfredo
authors.initials: A
authors.lastname: Minguela
authors.forename: Mariano
authors.initials: M
authors.lastname: Valdés
authors.forename: Domingo A
authors.initials: DA
authors.lastname: Pascual-Figal
mesh_terms: D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis* / Q000473:pathology; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D016014:Linear Models; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D012372:ROC Curve; D015203:Reproducibility of Results; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T