Impact of lipid abnormalities in development and progression of transplant coronary disease: a serial intravascular ultrasound study

OBJECTIVES We sought to determine the role of conventional atherosclerosis risk factors in the development and progression of transplant coronary artery disease (CAD) using serial intravascular ultrasound imaging. BACKGROUND Transplant artery disease is a combination of allograft vasculopathy and donor atherosclerosis. The clinical determinants for each of these disease processes are not well characterized. Intravascular ultrasound imaging is the most sensitive tool to serially study these processes. METHODS Baseline intravascular ultrasound imaging was performed 0.9 ± 0.5 months after transplantation to identify donor atherosclerosis. Follow-up imaging was performed at 1.0 ± 0.07 year to evaluate progression of donor atherosclerosis and development of transplant vasculopathy. Conventional risk factors for CAD included recipient age, gender, smoking history, diabetes mellitus, hypertension and hypercholesterolemia. RESULTS Donor-transmitted atherosclerosis was present in 36 patients (39%). At follow-up, progression of donor lesions was seen in 15 patients (42%) and 42 patients (45%) developed transplant vasculopathy, leaving 35 patients (38%) without any disease. There was no difference in any conventional risk factors in patients with and without allograft vasculopathy. However, the severity of allograft vasculopathy was associated with a larger increase in low density lipoprotein (LDL) cholesterol from baseline (p = 0.02). High one-year post-transplant serum triglyceride level and pretransplant body mass index were the only significant predictors (p = 0.03) for progression of donor atherosclerosis. CONCLUSIONS Conventional atherosclerosis risk factors do not predict development of allograft vasculopathy, but greater change in serum LDL cholesterol level during the first year after transplant is associated with more severe vasculopathy. Therefore, maintenance of LDL cholesterol as close to pretransplant values as possible may help to limit the rate of progression of acquired allograft vasculopathy.