Delayed onset of cardiac allograft vasculopathy by induction therapy using anti-thymocyte globulin.

Background: In this study we sought to compare the long-term effects of anti-thymocyte globulin (ATG) and muromonab-CD3 (OKT3) as induction therapy after heart transplantation, with special regard to cardiac allograft vasculopathy (CAV), post-transplant infections, post-transplant non-skin cancers and patient survival.
Methods: From 1988 to 1991, 25 heart transplant patients received OKT3 as induction treatment. Accordingly, 25 consecutive patients who received ATG and 25 consecutive patients without induction therapy were enrolled.
Results: At a follow-up period of 13.4 +/- 4.6 years, time to onset of non-significant and significant CAV was 8.77 +/- 3.38 and 11.60 +/- 4.28 years, respectively, in the ATG group, which was significantly delayed compared with 5.71 +/- 3.08 and 7.44 +/- 2.74 years, respectively, in the non-induction group. In the OKT3 group, time to onset of non-significant and significant CAV (6.10 +/- 2.73 and 7.86 +/- 3.19 years, respectively) did not differ significantly from the non-induction group. Ten- and 15-year actuarial survival rates of ATG- and OKT3-treated patients were not significantly different from those of patients without induction treatment.
Conclusions: Our study suggests the long-term advantage of ATG in prevention of cardiac allograft vasculopathy. In contrast, OKT3 failed to show such benefit. However, induction therapy with either ATG or OKT3 did not exhibit a significant beneficial effect on long-term patient survival.