Optical coherence tomography for early detection of cardiac allograft vasculopathy in pediatric heart recipients.

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a leading cause of graft failure following pediatric heart transplantation (HT). Early detection could improve long-term outcomes, but conventional coronary angiography often misses early-stage disease. Optical coherence tomography (OCT), a high-resolution intravascular imaging modality, may enable earlier and more sensitive CAV detection.

METHODS

This retrospective study analyzed pediatric HT recipients who underwent OCT between 2012 and 2024. OCT-derived maximal intima thickness (MIT) and cross-sectional area ratios were correlated with coronary angiography findings, hemodynamic data, CAV risk factors, and immunosuppressive regimens. Longitudinal analysis was performed in patients with serial OCT.

RESULTS

In 214 examinations (386 vessels) from 67 patients (median age 3.1 years, IQR 1.8-8.2, 49 % female, median 5.1 years post-HT, IQR 2.6-9.4), OCT-detected CAV (MIT ≥ 0.3 mm) was present in 31.9 % of vessels versus 8.0 % detected by angiography. MIT correlated with recipient and donor age, donor-recipient age difference, episodes of antibody-mediated rejection and was higher in adult donor grafts. Everolimus therapy was associated with significant lower MIT (p < 0.001). Over time, 73 % of grafts showed OCT-CAV with earlier onset (p = 0.037) and higher incidence (p = 0.005) in vessels from adult donors. Presence of CAV by angiography or OCT was associated with increased graft loss or dysfunction (log rank p = 0.044, HR 4.21, 95 %CI 1.16-15.28).

CONCLUSIONS

OCT detects early-stage CAV in pediatric heart transplant recipients with substantially greater sensitivity than angiography. Everolimus may mitigate early CAV progression. OCT offers significant potential for early detection and risk stratification.