Cardiac troponin T and C-reactive protein as markers of acute cardiac allograft rejection

Due to myocyte damage and an associated inflammatory response, it is possib le that cardiac troponin T and C-reactive protein (CRP) concentrations may correlate with the histologic grade of rejection in endomyocardial biopsy s amples obtained from patients who have received a heart transplant. In this study, 704 blood samples were obtained from 145 different heart transplant recipients just prior to endomyocardial biopsy. Plasma specimens were assa yed for troponin T and CRP concentration and the results compared with the assigned International Society of Heart and Lung Transplantation (ISHLT) hi stologic grade. Rejection was defined as an ISHLT grade of 3A or higher. Th e negative predictive values were near 80% in all cases, and a statisticall y significant increase in median troponin T concentration was observed acro ss ISHLT grades. After the first month posttransplantation, the specificity of the troponin T test (cutoff 0.1 ng/ml) was 95% and increased to 98% whe n false positives seen in renal disease patients, were excluded. Both tests demonstrated poor sensitivity and positive predictive value for rejection. Neither CRP nor troponin T had sufficient sensitivity to serve as an alter native to endomyocardial biopsy in the diagnosis of acute cardiac allograft rejection. However, the troponin T test had a high specificity, especially when patients with renal insufficiency were excluded, and could serve as a n adjunct test in this setting, When combined with a normal serum creatinin e, a troponin T greater than or equal to 0.1 ng/ml prior to endomyocardial biopsy correlated with graft rejection in almost all cases, making biopsy u nnecessary. (C) 2001 Elsevier Science BN. All rights reserved.