Immunohistochemical model to predict risk for coronary artery disease and failure in heart transplant patients.

ABSTRACT

Transplant coronary artery disease is the leading cause of long-term morbidity and mortality in cardiac transplantation. We developed a model for early identification of patients who subsequently develop coronary artery disease and graft failure. Serial biopsies obtained from 141 cardiac allografts (5.5 +/- 0.1 biopsies/patient) during the first 3 months post-transplant were evaluated immunohistochemically for deposition of myocardial fibrin, depletion of arteriolar tissue plasminogen activator, presence of arterial/arteriolar endothelial activation markers, and changes in vascular antithrombin. An immunohistochemical risk score was developed with a minimum value of 0 (normal) and a maximum value of 4 (most abnormal). Scores of 0 (low risk), 0.5-3.0 (moderate risk), and 3.5-4.0 (high risk) were analyzed for association with graft failure and development, severity, and progression of coronary artery disease detected using serial coronary angiograms (3.9 +/- 0.2/patient). Allografts with high immunohistochemical risk scores in the first 3months post-transplant developed more coronary artery disease (p<0.001), developed coronary artery disease earlier (p<0.001), developed more severe disease (p<0.001), and showed more disease progression (p<0.001) than allografts with moderate or low scores. Allografts with high immunohistochemical risk scores in the first 3 months post-transplant failed more (p<0.001) and failed earlier (p<0.001) than allografts with moderate or low scores. The present study demonstrates that early changes in the microvasculature are associated with impending coronary artery disease and graft failure in cardiac allograft recipients and suggests that treatment needs to be instituted early after transplantation in order to improve outcome.