UTILITY OF SURVEILLANCE BIOPSIES IN INFANT HEART-TRANSPLANT RECIPIENTS

Background: Endomyocardial biopsy remains the primary means of rejecti on surveillance after orthotopic heart transplantation in adults. Perp etual surveillance endomyocardial biopsy has been questioned, however, because of low yield beyond the early posttransplantation period. Thi s issue has not been adequately studied in the pediatric population. T he objectives of this study were to define the rate of rejection in in fants undergoing orthotopic heart transplantation, correlate rejection with signs and symptoms, and evaluate the utility of surveillance end omyocardial biopsy. Methods: Records of all patients 24 months of age or younger undergoing orthotopic heart transplantation were reviewed; 38 patients underwent 42 transplantations; 256 endomyocardial biopsies were performed for surveillance, cardiac symptoms, noncardiac symptom s, or lowered immunosuppression. Results: There were 22 rejection epis odes International Society for Heart and Lung Transplantation grade 1B or higher, half of which occurred in neonates 30 days of age or young er. Linearized rejection rates and actuarial freedom from rejection we re not different between neonates and older infants. Linearized reject ion rates reached a plateau 3 months after orthotopic heart transplant ation of 0.07 episodes/100 patient days. No positive surveillance endo myocardial biopsies were obtained beyond 6 months after orthotopic hea rt transplantation. The probability of a positive biopsy (Internationa l Society for Heart and Lung Transplantation grade 1B or higher) was 2 0% or more for any other indication (odds ratios for rejection were 12 .9 for cardiac symptoms, 3.3 for noncardiac symptoms, and 10.8 for low ered immunosuppression as determined by logistic regression more than 6 months after orthotopic heart transplantation). Conclusions: Rejecti on rates are not different between neonatal and older infants, and end omyocardial biopsies done solely for surveillance beyond 6 months afte r orthotopic heart transplantation rarely yield positive results.