Development of transplantation vasculopathy and progression of donor- transmitted atherosclerosis: Comparison by serial intravascular ultrasound imaging

Background - Transplant coronary artery disease is a combination of atherosclerosis transmitted from the donor and new lesions of allograft vasculopathy. We sought to determine the morphological characteristics of allograft vasculopathy and differentiate it from donor-transmitted atherosclerosis with serial intravascular ultrasound. Methods and Results - Intravascular ultrasound examination was performed in 93 patients at 27.2±15.0 and 369.7±23.9 days after transplantation. The maximally and minimally diseased sites were selected in each segment as defined by Coronary Artery Surgery Study classification. For each matched site, maximal plaque thickness was measured. Lesions (maximum plaque thickness ≥0.5 mm) present at baseline examination were defined as donor lesions. On follow-up, lesions that developed at previously normal sites were defined as de nova lesions. The distribution and severity of donor and de nova lesions were similar in proximal, mid, and distal segments. The de nova lesions were less focal (43% vs 74%) and more circumferential (69% vs 45%) compared with the donor lesions, but there was significant morphological heterogeneity. Similar numbers of patients with and those without donor lesions developed de nova lesions. Moreover, progression of donor lesions was not associated with the presence or absence of de nova lesions. Conclusions - Differentiation between early allograft vasculopathy from conventional atherosclerosis by distribution and morphology of lesions alone is difficult. Serial intravascular ultrasound imaging with early baseline examination is necessary to make this distinction. This distinction is important because the progression of donor lesions and the development of de nova lesions are independent of each other.