667: The Use of Intravascular Ultrasound in the Diagnosis of Cardiac Allograft Vasculopathy in Pediatric Heart Transplant Recipients: A Ten Year Experience

Purpose: Intravascular ultrasound (IVUS) has been used routinely in the diagnosis of cardiac allograft vasculopathy (CAV) in heart transplant recipients of all ages. This retrospective study evaluates our experience with IVUS in our pediatric population over a 10-year period (7/97 - 6/08). Methods and Materials: Beginning at 7 years of age, IVUS was incorporated into the annual study. Morphometric analysis was performed on ten random vessel segments. The degree of intimal changes was assessed based on the Stanford Classification. Patients were divided into those with minor intimal thickening (Class 1/2) and those with moderate to severe thickening (Class 3/4). Outcome variables included graft loss, retransplantation, death, CAV on autopsy, CAV +/- angiographic changes on catheterization(CAV/Angio +), and other causes of graft loss. Comparisons were made using chi-square analysis. A p-value < 0.05 was considered significant. Results: Since 1997, 163 children have undergone 415 IVUS procedures. There were 3 procedural complications, all coronary vasospasm that resolved without sequelae. The table shows the comparison between the two groups. There was a significant association between the development of intimal thickening and CAV. The vast majority of graft loss was due to CAV in the Class 3/4 group (13/15 cases). The majority of graft loss in the Class 1/2 group was not due to CAV and all the cases resulted in death. There was no significant difference between the two groups when comparing death or other causes of death. Conclusions: In conclusion, the presence of significant intimal changes on IVUS correlates strongly with the development of CAV in pediatric heart transplant recipients. IVUS is an excellent tool for the early diagnosis of developing CAV. (Table presented).