Serum Cardiac Troponin-T Concentrations Predict Development of Coronary Artery Disease in Heart Transplant Patients1

BACKGROUND: Development of coronary artery disease in cardiac allograft recipients is the major cause of graft failure after the first year of transplantation. Unfortunately, there is no noninvasive method of identifying patients at greatest risk of developing this disease. We have asked whether serum concentrations of cardiac troponin-T predict development of coronary artery disease. METHODS: Annual coronary angiograms, serial endomyocardial biopsies, and serum cardiac troponin-T concentrations were obtained from 68 cardiac transplant patients who were followed for 68.8+/-11.9 months after surgery. Troponin-T concentrations were measured by using an enzyme-linked immunosorbent assay, and biopsies were assessed histologically for rejection grades and immunohistochemically for cellular infiltrates, arteriolar endothelial activation, fibrin deposits, and vascular fibrinolytic and anticoagulant components. RESULTS: Troponin-T values did not associate with demographic, clinical, or laboratory findings, but they significantly associated with arteriolar endothelial activation (P<0.001), fibrin deposition (P<0.001), depletion of vascular fibrinolytic (P=0.007) and anticoagulant components (P=0.02), and infiltration of macrophages (P <0.001) but not T lymphocytes (P=0.36). Troponin-T concentrations also significantly associated with future development of coronary artery disease (P<0.001). Patients with persistent troponin-T values of 0.10 ng/ml or greater were found to develop the disease within 8.7+/-2.1 months, whereas patients who had initial troponin-T values of 0.10 ng/ml or greater and subsequently fell and remained below 0.10 ng/ml did not develop coronary artery disease in 40 months. CONCLUSIONS: Troponin-T concentrations significantly associated with macrophage infiltrates, microvascular fibrin deposits, arteriolar endothelial activation, depletion of vascular fibrinolytic and anticoagulant components, and the future development of coronary artery disease. The troponin-T assay is an outpatient procedure performed on small amounts of blood at little cost, risk, or inconvenience, and it appears to be the first biochemical predictor of transplant-induced coronary artery disease.