Background: The effect of pre- or post-operatively acquired diabetes mellitus on survival after heart transplantation remains controversial. The influence of transplant era on diabetes-associated survival is unknown.
Methods: A retrospective database analysis was performed on all cardiac transplant recipients followed up at our institution between 1986 and 2003. Diabetes mellitus was diagnosed based on oral glucose tolerance testing.
Results: Survival was analyzed in 243 patients (80% male, mean age 52.2 years, mean follow-up 5.22 years). Kaplan-Meier survival analysis demonstrated significantly worse (p = 0.0001) survival both early (months 0 to 12) and late (>5 years) after transplantation in pre-operative diabetics (n = 53) compared with non-diabetics (n = 190). Pre-operative diabetes was identified as the only independent risk factor for decreased long-term (>1 year) survival (p = 0.004). In contrast, no effect on survival (p = 0.5) was demonstrated in patients becoming diabetic only after heart transplantation (n = 39). At 12 months post-transplant renal function was significantly impaired in diabetics (p = 0.025); acute rejection, cytomegalovirus (CMV) infection and transplant vasculopathy occurred with similar frequency. Causes of death were similar in diabetics and non-diabetics. Reduced long-term survival in pre-operative diabetics was seen in the early transplant era (1986 to 1994) (p < 0.0001), but not in the more recent era (1995 to 2003) (p = 0.5).
Conclusions: Pre-transplant but not post-transplant diabetes confers an adverse risk for survival (short and long term). Diabetes-associated long-term survival appears to have improved in the recent era, supporting continued transplantation in diabetics under close surveillance and aggressive medical management.