Impact of age on ultrastructural changes in internal thoracic artery in patients undergoing coronary artery bypass grafting

Aim: Age is a known risk factor for cardiovascular disease and plays a role in the atherosclerotic process. The purpose of this study was to look at the impact of aging and associated risk factors on the ultrastructure of internal thoracic arteries in patients undergoing coronary artery bypass grafting.

Material and Methods: We enrolled 27 patients undergoing elective coronary artery bypass grafting at our institute between August-October 2018. Age groups were classified into three: 50-59, 60-69, and 70-79 years. A 2-mm distal portion of the vessel was excised when the ITA was surgically harvested. Transmission electron microscopy was used to investigate the ultrastructural changes. Cell structure, tissue edema, and endothelial mitochondria were all assessed and rated by using semiquantitative analysis.

Results: The ultrastructure of the vessel wall exhibited no significant changes in Group-I. Endothelial wall irregularity with endothelial cells of varying thickness was seen in Group-II. Group-III showed subendothelial edema and localized endothelial wall discontinuity. These changes were particularly severe in the elderly and patients with comorbidities. The greatest permanent cell alterations, such as massive vacuoles and organelle loss, were identified in two patients with kidney failure and hypertension. The average scores assessing the severity of changes in endotohelial cell structure (P  .001), tissue edema (P  .001), and mitochondria (P  .001) were significantly different between groups showing more severe changes with aging.Conclusions: In elderly patients with comorbidities, the ITA endothelium may exhibit severe ultrastructural alterations, with the most permanent abnormalities reported in those with hypertension and kidney failure. However, The ITA remains the gold standard in CABG with its native resistance to atherosclerosis.