Patterns of Early Coronary Artery Changes in Pediatric Heart Transplant Recipients Detected Using Optical Coherence Tomography.

BACKGROUND: Cardiac allograft vasculopathy, the leading cause of graft failure in pediatric heart transplant recipients, is characterized by diffuse and concentric coronary intimal thickening. Early treatment yields better outcomes. While coronary angiography is the standard for cardiac allograft vasculopathy screening and diagnosis, it only identifies luminal narrowing, which occurs in more severe disease. Coronary optical coherence tomography (OCT) is a high-definition intravascular imaging modality that may offer earlier diagnosis. We used OCT to investigate coronary intimal thickening in pediatric transplant recipients and examined its (1) location (ie, vessel type and location) and (2) nature (ie, characteristics of cross-sectional and longitudinal thickening). METHODS: Sites collected coronary angiography and OCT data from participants (N=258 vessel segments from 73 individuals; median age: 11.5 years [8.4-15.3]; 55% male). Images were collected from the left anterior descending, left circumflex, and right coronary arteries, and location (ie, proximal, middle, and distal) were classified using coronary angiography. RESULTS: OCT identified 32 vessel segments meeting criteria for significant thickening, 88% of which were angiographically silent. Longitudinal thickening was segmental rather than global in 88%, and cross-sectional thickening was 48% eccentric and 52% concentric. Intimal thickening prevalence and severity measures did not consistently differ between coronary artery type (P=1.000) or location (P=0.248) but increased with time since transplant and age at transplant and OCT procedure. CONCLUSIONS: In pediatric transplant recipients, we observed a surprisingly high prevalence of segmental and eccentric intimal thickening. Insights from intravascular imaging suggest these patterns of coronary vascular changes may precede overt cardiac allograft vasculopathy. Identifying early changes may offer opportunity for enhanced surveillance and earlier intervention.

Intraoperative Extubation Post Arterial Switch Operation for Transposition of the Great Arteries With Intact Ventricular Septum: A One-Year, Single Center Experience.

We sought to examine the clinical impact of intraoperative extubation (IE) in neonates undergoing the arterial switch operation (ASO) for D-transposition of the great arteries with intact ventricular septum (dTGA/IVS). This was a single center retrospective study of patients who underwent ASO for dTGA/IVS in the 12 months after an institutional change in practice favoring IE when clinically feasible. A control group was obtained by identifying the same number of consecutive patients with dTGA/IVS who underwent ASO immediately prior to this institutional change in practice, none of whom were extubated intraoperatively. Primary outcome measures included morbidity, mortality, length of hospital and intensive care unit stay and reintubation rates. There were no significant differences in the preoperative and operative characteristics between the 2 groups. Of the 10 patients who underwent ASO for dTGA/IVS in the 12 months post institutional change in practice, all (100%) were extubated intraoperatively and none (0%) required reintubation. The median length of intensive care unit stay was 2 days for both the intraoperative and non-IE groups (mean 2.2 and 3 days respectively). The median length of stay in hospital was 4 days in the IE group and 5.5 days in the non-IE group (mean 4.5 and 6 days respectively). No patients died and there was no significant difference in morbidity between the 2 groups. Our data suggests IE post ASO for dTGA/IVS is safe and displays a statistically insignificant trend toward earlier discharge from hospital.