Quantitative Coronary Angiography Can Predict Cardiac Allograft Vasculopathy in Pediatric Heart Transplant Recipients

Abstract

Cardiac allograft vasculopathy (CAV) is a leading cause of death and re-transplantation (tx). Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are increasingly used for earlier detection, but lengthen procedure time and cost, and are unsuitable in small children. Coronary angiography is routine in all age groups but may be subjectively interpreted. We hypothesized that serial analysis of quantitative coronary angiography (QCA) is possible in infants and children and may also predict disease progression. Pediatric recipients between Feb 1999 - July 2012 were studied. QCA was performed in two projections of the same region of the right (RCA), left (LCA), and circumflex (Cx) coronary arteries for each study using standard commercially available software. Mean lumen diameter (MLD) was recorded and an average value assigned to each vessel. The first angiogram served as baseline and percentage change from that was determined for each vessel. Only pre-CAV angiograms were reviewed. Included subjects were separated into CAV and NoCAV groups. Repeated measures ANOVA was used to compare MLD change over multiple observations. 16 patients met inclusion criteria for review; there were 9 patients in the CAV group (CAV1+ was eventually diagnosed 9.2±3.7 years post-tx). There were no significant differences between the groups with respect to transplant age (TxAge) or gender. CAV subjects showed significant decrements in MLD over time (p< .05), while those with NoCAV demonstrated an increase in diameter. QCA can be performed in pediatric patients, even the very young. A decrement in MLD over time appears predictive of future overt CAV by angiography. This quantitative tool could supplant IVUS and OCT in outcome studies at no added cost, procedure time or risk beyond routine coronary angiography.