Association of Intimal Neovessels Noted by Optical Coherence Tomography with Cardiac Allograft Vasculopathy

Background Cardiac allograft vasculopathy (CAV) is a leading cause of graft failure in cardiac transplant recipients. Progression of intimal thickening noted during routine surveillance intracoronary imaging is associated with the development of CAV. However, mechanisms of CAV development are poorly understood and targets for therapy modification remain elusive. We investigated the association of neovessels (INs) within the intima, noted by optical coherence tomography (OCT) during routine CAV surveillance imaging, with intimal thickening and co-incident CAV. Methods Coronary angiography and OCT images of 45 consecutive cardiac transplant recipients undergoing surveillance coronary imaging were reviewed. The presence of INs, defined as dark, tubular or rotund intimal structures, measuring 50-200 µm in diameter, noted in at least three OCT frames, was quantified. CAV diagnosis was determined by utilizing the International Society of Heart and Lung Transplant classification system. Demographic and clinical data was obtained by chart review. Significant associations between the presence of INs and CAV, intimal thickening, and demographic features were evaluated. Results INs were observed in 22/45 evaluated patients (49%), while angiographic CAV was observed in 24/45 patients, with a significant association noted between the presence of INs and CAV (p < 0.001). INs were also associated with increasing intimal thickness (p < 0.001), co-morbid hypertension (p = 0.010), and increasing transplant age (p= 0.002) on multivariate analysis. Conclusion INs are prevalent in cardiac transplant recipients and are significantly associated with CAV, increased intimal thickness, increasing transplant age, and co-morbid hypertension. Further investigation is warranted regarding the temporal relationship of IN development and the onset of CAV, as well as the mechanisms of IN development in this population.