Serum cardiac troponin-T concentrations predict development of coronary artery disease in heart transplant patients

Background. Development of coronary artery disease in cardiac allograft rec ipients is the major cause of graft failure after the first year of transpl antation. Unfortunately, there is no noninvasive method of identifying pati ents at greatest risk of developing this disease. We have asked whether ser um concentrations of cardiac troponin-T predict development of coronary art ery disease. Methods. Annual coronary angiograms, serial endomyocardial biopsies, and se rum cardiac troponin-T concentrations were obtained from 68 cardiac transpl ant patients who were followed for 68.8+/-11.9 months after surgery. Tropon in-T concentrations were measured by using an enzyme-linked immunosorbent a ssay, and biopsies were assessed histologically for rejection grades and im munohistochemically for cellular infiltrates, arteriolar endothelial activa tion, fibrin deposits, and vascular fibrinolytic and anticoagulant componen ts. Results. Troponin-T values did not associate with demographic, clinical, or laboratory findings, but they significantly associated with arteriolar end othelial activation (P<0.001), fibrin deposition (P<0.001), depletion of va scular fibrinolytic (P=0.007) and anticoagulant components (P=0.02), and in filtration of macrophages (P<0.001) but not T lymphocytes (P=0.36), Troponi n-T concentrations also significantly associated with future development of coronary artery disease (P<0.001). Patients with persistent troponin T val ues 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 d evelop coronary artery disease in 40 months. Conclusions. Troponin-T concentrations significantly associated with macrop hage infiltrates, microvascular fibrin deposits, arteriolar endothelial act ivation, depletion of vascular fibrinolytic and anticoagulant components, a nd the future development of coronary artery disease. The troponin-T assay is an outpatient procedure performed on small amounts of blood at little co st, risk, or inconvenience, and it appears to be the first biochemical pred ictor of transplant-induced coronary artery disease.