Influence of size disparity of transplanted hearts on cardiac growth in infants and children

Objective We aimed to evaluate the influence of size disparity of the transplanted heart on cardiac growth in infant and child recipients by comparing donor body surface area (BSA) and cardiac dimensions during transplantation to the corresponding parameters of the recipient over a period of time. Methods A retrospective review of medical and echocardiographic records of 147 children (5.3 ± 4.0; median, 4.1; range, 1 month–15 years) who underwent orthotopic heart transplantation was done. The patients were divided into age groups as follows: less than 1 year (n = 23), 1 to 2 years (n = 26), more than 2 to 5 years (n = 18), more than 5 to 10 years (n = 27), and more than 10 to 15 years (n = 53). Donor/recipient BSA ratio was determined during transplantation. Cardiac dimensions were measured 30 days after transplantation and compared at 1 year, 2 to 5 years, and 5 to 10 years after transplantation. Results There were no significant differences in the ventricular end-diastolic diameter, volumes, and mass among those with a donor/recipient BSA ratio of less than 0.80, 0.8 to 1.2, and more than 1.2 ( P = .80, .44, and .48, respectively). In all the cardiac dimensions and volumes measured, donor–recipient mismatch did not influence the continuous growth of the heart, as indicated by the measured parameters, in accordance with the recipients' increase in BSA over time. All calculated Z-scores at 1 year, 2 to 5 years, and 6 to 10 years after transplantation were normal when indexed to BSA. Conclusions This study demonstrates that despite size disparity of a transplanted heart, it undergoes normal growth in diastolic dimensions, volumes, and myocardial mass over time as appropriate for body growth after cardiac transplantation in infants and children.