Coronary plaque morphologic characteristics early and late after heart transplantation: In vivo analysis with intravascular ultrasonography,

To characterize plaque morphologic characteristics of transplant coronary artery disease early and late after cardiac transplantation, 72 patients were studied with intravascular ultrasonography during routine coronary angiography (group 1, 25 patients ≤2 months after surgery; group 2, 47 patients ≥12 months after surgery). Both groups had comparable baseline characteristics. Three hundred fifty-one segments were imaged in 127 coronary arteries (4.9 ± 1.8 segments per patient). By intravascular ultrasonography, relevant intimal thickening (>0.3 mm) was found in the majority of patients (68% for group 1 and 72% for group 2). Angiography detected abnormal findings in only 16% and 32% for groups 1 and 2, respectively. Mean intimal index was higher in patients late after transplantation (27% ± 12% vs 17% ± 12%, respectively; p < 0.01). Maximal and mean plaque thickness were comparable in both groups, whereas a higher mean plaque circumference was found in group2 (278 ± 66 degrees vs 211 ± 75 degrees, respectively; p < 0.002). The lesions were more eccentric in patients early after transplantation (mean eccentricity index 95% ± 7% vs 77% ± 15%, respectively; p < 0.0001). Diffuse, concentric intimal thickening was not a common pattern. Maximal plaque thickness correlated with donor age ( r = 0.50, p < 0.0001). Coronary lesions were frequent even early after transplantation, with predominantly eccentric plaque morphologic characteristics indicative of preexisting atherosclerosis. Later after transplantation, a more homogeneous plaque distribution was seen, partly with diffuse concentic intimal thickening. Late transplant coronary artery disease appears to be a combination of preexisting native and acquired immune-mediated coronary artery disease. (Am Heart J 1997;133:29-35.)