RESUMO
OBJECTIVES: The standard for diagnosing allograft rejection after heart transplantation is the endomyocardial biopsy, but the value of routine surveillance biopsies after 2 years after transplant is controversial. The objective of this study was to determine the necessity and safety of surveillance biopsies and to correlate rejection with signs and symptoms beyond the second post-transplant anniversary in pediatric patients. STUDY DESIGN: We reviewed the results of 899 biopsies and coincident clinical histories in 56 pediatric patients, comprising 314 patient-years of follow-up. Patients were classified as having symptoms or not based on a blinded review of their clinical status and echocardiograms. Biopsies were classified as negative or positive with established criteria. RESULTS: After biopsies performed less than 2 years after transplant or as a follow-up for a positive biopsy were excluded, 481 biopsies were available for analysis, of which 20 (4%) were positive. Positive biopsies were found in 15 (3%) of 456 biopsies in patients without symptoms compared with 5 (20%) of 25 biopsies in patients with symptoms. Patients with symptoms were 6 times more likely to have a positive biopsy compared with patients without symptoms. Of the positive rejection episodes, 75% occurred in patients without symptoms. CONCLUSION: Although rejection is uncommon in pediatric patients greater than 2 years after transplant, episodes of treatable allograft rejection can occur in the absence of clinical signs and symptoms. This study emphasizes the safety of and the need to continue to perform routine surveillance biopsies in patients without symptoms, even after the second post-transplant year.