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

Background-Transplant coronary artery disease isa combination of atheroscle rosis transmitted from the donor and new lesions of allograft vasculopathy. We sought to determine the morphological characteristics of allograft vasc ulopathy and differentiate it from donor-transmitted atherosclerosis with s erial intravascular ultrasound. Methods and Results-Intravascular ultrasound examination was performed in 9 3 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 def ined by Coronary Artery Surgery Study classification. For each matched site , maximal plaque thickness was measured. Lesions (maximum plaque thickness greater than or equal to 0.5 mm) present at baseline examination were defin ed as donor lesions. On follow-up, lesions that developed at previously nor mal sites were defined as de novo lesions. The distribution and severity of donor and de novo lesions were similar in proximal, mid, and distal segmen ts. The de novo lesions were less focal (43% vs 74%) and more circumferenti al (69% vs 45%) compared with the donor lesions, but there was significant morphological heterogeneity, Similar numbers of patients with and those wit hout donor lesions developed de novo lesions. Moreover, progression of dono r lesions was not associated with the presence or absence of de novo lesion s. Conclusions-Differentiation between early allograft vasculopathy from conve ntional atherosclerosis by distribution and morphology of lesions alone is difficult. Serial intravascular ultrasound imaging with early baseline exam ination is necessary to make this distinction. This distinction is importan t because the progression of donor lesions and the development of de novo l esions are independent of each other.