Abstract 15229: Use of NT-proBNP, CRP or Troponin T For Non-Invasive Detection of Allograft Rejection in Heart Transplant Recipients

Abstract

Introduction: Acute allograft rejection (AR) is a common problem after heart transplantation (HTx), and endomyocardial biopsy (EMB) is still the gold standard for this diagnosis. Earlier studies suggest a role for biomarkers in the noninvasive diagnosis of AR. We examined the value of serial measurements of NT-pro-B-type natriuretic peptide (BNP), C-reactive protein (CRP) and troponin T (TropT) for detecting AR. The aim of this study was to evaluate the natural history of these biomarkers, as well as their predictive value for AR, in HTx patients after transplantation.

Methods: From 2005 to 2010, 75 consecutive HTx patients were included. BNP, CRP and TropT were measured at 15±3 (mean±SD) consecutive routine EMB surveillance visits during the first year of follow-up. AR was defined as ISHLT grade ≥ 2R. Associations between temporal biomarker patterns and first AR were assessed utilizing a joint modeling (JM) approach, which combines a mixed-effects model for the serial biomarker measurements with a Cox proportional hazards model for the risk of AR.

Results: Mean age of the patients at HTx was 48±9.9 years, and 68% were men. A total of 1095 biopsies and concurrent blood samples were obtained. During the first year of follow up, 55 patients (73%) experienced at least one episode of AR. All biomarkers were elevated directly after HTx and reached steady-state after approximately 12 weeks, both in patients with and without AR (fig. 1). No associations were present between the temporal patterns of BNP, CRP or TropT and AR both early (weeks 0-11) and late (weeks 12-52) in the course after HTx (hazard ratios obtained with JM for weeks 12-52: 1.00 (95% CI 0.58-1.74), 1.72 (0.90-3.26) and 0.95(0.56-1.59), per ln(unit)).

Conclusions: High postoperative BNP, CRP and TropT values decline progressively, reaching a steady state after approximately 12 weeks post HTx. No associations could be showed between temporal evolution of these biomarkers and detection of acute AR in the first year post HTx.