Coronary artery intimal thickening and ventricular dynamics in pediatric heart transplant recipients

OBJECTIVE: Pediatric heart transplant recipients are at risk of posttransplant coronary artery disease known as cardiac allograft vasculopathy (CAV), and also may develop diastolic dysfunction. As CAV begins with a process of progressive intimal thickening, these occult diffuse changes may be detected using optical coherence tomography (OCT). We hypothesized that the development of CAV, as identified via OCT, may be a mechanism of declining ventricular function. Accordingly, the purpose of this study was to assess coronary artery intimal thickening and LV strain in children who have undergone heart transplantation. METHODS: In 17 children, we analyzed OCT images for coronary intima and media thickness, and cross-sectional area (CSA). We also performed speckle tracking imaging (STI) of the LV to determine longitudinal strain and strain rate, in addition to standard echocardiographic measures. RESULTS: Longitudinal diastolic strain rate was associated with maximum intima thickness (r = -.497, P = .042), intima CSA, (r = -.489, P = .047), maximum media thickness (r = -.503, P = .039), and media CSA (r = -.614, P = .009). The intima maximum thickness, intima/media, and intima/lumen ratios were associated with stroke volume index (Std. β = -0.487, P = .023 and Std. β = -0.488, P = .022, respectively). CONCLUSIONS: These findings suggest coronary artery intimal thickening may be mechanistically linked to changes in ventricular function following cardiac transplantation.