Antithymocyte globulin induction therapy for adult heart transplantation: A UK national study

Abstract

Induction therapy with antithymocyte globulin (ATG) after heart transplantation (HTx) has never been assessed in a placebo-controlled randomized trial. We investigated trends in use of ATG and its relationship to outcome after HTx in a national cohort. Between July 1995 and March 2008, 2,151 adult HTxs were performed. Patients given OKT3 or an interleukin-2 receptor antagonist, repeat transplants, heterotopic, and multi-organ transplants were excluded, leaving 2,086 HTx for analysis. Of these, 1,143 (55%) received induction with ATG. The proportion of patients given ATG increased from 26% in June 1995 to 75% in August 2007 (p < 0.01). The age and gender distributions of recipients and donors were similar in the ATG and non-ATG groups. Survival to 10 years was similar: 56.2% in the non-ATG group vs 55.9% in the ATG group (p = 0.95). The number of treated rejection episodes in the first year was lower in the ATG group (incidence rate ratio, 0.76; 95% confidence interval [CI], 0.68-0.85, p < 0.01), but the number of infective episodes was higher (incidence rate ratio, 1.18; 95% CI, 1.00-1.39, p = 0.048), and these differences remained after risk adjustment, with an adjusted incidence rate ratio of 0.85 (95% CI, 0.75-0.95, p < 0.01) and 1.21 (95% CI, 1.02-1.44; p = 0.027). Deaths due to infective causes were higher in the ATG group (p = 0.03). There has been a trend towards an increased use of induction therapy. There was no change in overall survival, but ATG induction was associated with a decreased incidence of rejection and an increase in infection.