Optical Coherence Tomography for the Early Detection of Coronary Vascular Changes in Children and Adolescents After Cardiac Transplantation: Findings From the International Pediatric OCT Registry.

OBJECTIVES: This study sought to describe the initial findings from the International Pediatric Optical Coherence Tomography (OCT) registry in pediatric heart transplant recipients.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a common cause of late graft failure and mortality in pediatric heart transplant recipients. Early diagnosis may improve outcomes. OCT is a high-resolution intravascular imaging technique that has the potential to identify CAV earlier than angiography.

METHODS: OCT and angiography of the coronary arteries were performed in pediatric heart transplant recipients at participating centers. Demographics, clinical data, medications, episodes of rejection, and angiographically confirmed CAV were collected for each case. OCT and angiography images were analyzed in a central core imaging laboratory. Intimal thickness and intima/media cross sectional area (I/M CSA) ratios were calculated for each case. Intimal thickness ≥0.25 mm was defined as abnormal and ≥0.4 mm as severe intima thickening. I/M CSA ratio of ≥1 was defined as abnormal. OCT findings were compared to angiographic findings for each case.

RESULTS: Across 3 centers, 110 cases were analyzed from 76 patients. Intimal thickening was present in 26 of 110 cases. Eleven of these cases had severe intima thickening (≥0.4 mm) and notably, angiography results were normal in 8 cases. All 5 cases with a median I/M CSA ratio of ≥2 had normal angiography. The maximal intima thickness was ≥0.25 mm in 24% and ≥0.4 mm in 10% of cases. Median I/M CSA ratio was ≥1 for 80% of cases. I/M CSA ratio was significantly higher in cases with concurrent CAV (p = 0.03). Maximal intima thickness was significantly greater in cases with current or previous rejection (p = 0.01). I/M CSA ratio was significantly lower in patients treated with statins (p = 0.01). OCT findings alone prompted a change to medical management in 17% of cases.

CONCLUSIONS: OCT provides important insights into coronary vascular changes not detected by angiography in pediatric transplant recipients. The use of OCT for pediatric heart transplant recipients should be further investigated, given its potential to impact the management of CAV.