Cardiac allograft rejection late after transplantation is a risk factor for graft coronary artery disease.

BACKGROUND

Graft coronary artery disease (CAD) is an increasingly important problem during long-term survival after heart transplantation, but the importance of cellular rejection, in particular late after transplantation, remains undetermined.

METHODS AND RESULTS

We analyzed 492 coronary angiographies (967+/-705 days after transplantation; range, 49 days to 9.4 years) and 5201 endomyocardial biopsies (518+/-648 days after transplantation) from 156 patients (age, 47+/-11 years). Patients with angiographically detectable graft CAD had significantly more episodes of rejection requiring augmentation of immunosuppressive therapy (i.e., International Society of Heart and Lung Transplantation score > or = 3A) than those without graft CAD during the first (3.7+/-2.6 vs. 2.2+/-2.0, P<0.001) as well as subsequent years after transplantation (1.2+/-1.9 vs. 0.4+/-0.9, P<0.01). Multivariate logistic regression analysis including established risk factors for CAD, ischemic time, gender and age of donors and recipients, number of mismatches, cytomegalovirus infection, and drug therapy showed that the number of rejections during the first [odds ratio (OR)=1.39, P<0.005] as well as subsequent years (OR=1.49, P<0.05), previous cytomegalovirus infection (OR=3.21, P<0.05), donor age >40 years (OR=2.97, P<0.05), and current or former smoker status (OR=2.76, P<0.05) were independent predictors of graft CAD. In patients without angiographically detectable graft CAD 1 year after transplantation, the number of rejections after the first year was even more strongly related to graft coronary artery disease than in the total patient population, underlining the importance of late cellular rejection (OR=1.74, P<0.005).

CONCLUSION

Rejection requiring augmentation of immunosuppression early and late after transplantation is an independent risk factor for the development of angiographically detectable graft CAD. Hence, the search for and treatment of moderate or severe rejection seems to be prudent even late after transplantation.