Analysis of the complex effect of donor's age on survival of subjects who underwent heart transplantation

BACKGROUND: Only half of the patients waiting for a heart transplant undergo surgery, whereas several patients continue to die while on the waiting list. Donor organ availability still represents a major problem with respect to reducing the length of the cardiac transplant waiting list. One option to improve donor availability is the use of so called "marginal donors." The aims of the present study are to analyze the short-mid term survival of cardiac transplanted patients in Italy, and investigate the effect of donor age on prognosis. METHODS: A prospective cohort study including all adult patients who underwent heart transplantations in Italy was used to analyze the main factors contributing to organ survival. RESULTS: From 1995-2002, 2,504 adult subjects underwent a cardiac transplant, and were followed up for a period of 540.9 days. Overall, 1-year graft survival was 83.1%. Organs from donors older than 55 years had a lower survival than organs from younger donors. By multivariate analysis, both donor's and recipient's age seem to be important determinants of graft survival. A more sophisticated analysis shows that the trend of the risk of graft failure according to donor's age is not linear, with a peak at age 47.3 years, and differs according to sex. CONCLUSIONS: Results from the present analysis suggest that the association between heart transplant survival and donor's age is not a linear one, but follows a complex mathematical model, with influences of sex, at least in our sample.