Using previously described models of diabetes-induced transplant coronary artery atherosclerosis (TxCAD), we quantitatively assessed TxCAD using computer-assisted morphometric measurements. More than 95% of the evaluated vessels were intramyocardial vessels. The first and last tertile of the vessel size distribution were evaluated for the presence of TxCAD. Severe TxCAD, defined as a luminal occlusion > or =75%, was more prevalent in the larger vessels. We observed a differential involvement based on vessel size in diabetes-induced TxCAD.