Histology of atherosclerotic plaque from coronary arteries of deceased patients after coronary artery bypass graft surgery

BACKGROUND AND AIM

Ischaemic heart disease is an important health problem. The characteristics of atherosclerotic plaques determine patient outcome. The aim of this study was to determine the histological grade of coronary atherosclerotic lesions in deceased patients after coronary artery bypass graft surgery, and to identify the complications of the severe plaques.

METHOD

A descriptive, cross-sectional, prospective study was carried out on 21 anatomical pieces of deceased patients over a period of 3 years. The epicardial coronary arteries were sectioned transversally every 1cm, and the odd numbered fragments and the regions of the anastomosis with the grafts were selected. They were embedded in paraffin, stained with haematoxylin-eosin, and the histological slides were studied using an Olympus BHM microscope.

RESULTS

An age over 50 years (85.7%), male gender (81.0%), and smoking (66.7%) predominated. Peri-operative infarction (38.1%) and cardiogenic shock (33.3%) were the main direct causes of death. The majority of the grafts were of venous origin (64.6%), and 149 lesions were detected, of which 116 (77.8%) were severe plaques, and 47.4% of them were located in the left anterior descending artery. The large majority (81.9%) of the lesions were located in the arterial segments proximal to the graft. A total of 255 histological complications were detected in the severe plaques, with 75.0% showing calcification. Hypertensive patients had more plaques with more complications, but no statistically significant association was found between these variables.

CONCLUSIONS

Severe plaques predominated, mostly located in the proximal segments of the coronary arteries, and the left anterior descending was the most affected artery. Calcification was the most observed complication in the severe plaques.