[Morphologic discrepancies of coronary atherosclerotic lesions between patients with stable and unstable angina plus acute myocardial infarction].

OBJECTIVE

To compare the morphological difference of coronary atherosclerotic plaques in patients with stable angina(SA), unstable angina (UA) and acute myocardial infarction (AMI).

METHODS

101 autopsy cases of patients with SA, UA and/or AMI were studied using routine histological and immunohistochemical staining.

RESULTS

Coronary atherosclerotic plaques in SA patients were mainly the fibrous plaques with no or just very small necrotic cores; rich in smooth muscle cells and collagen fibers, less foamy cells (stable plaque), low incidence of plaque rupture (14% only) and no thrombosis found. The atherosclerotic plaques in UA and AMI patients were mainly the atheroma (unstable plaque) with large necrotic core (> 40%), thin fibrous cap, less smooth muscle cells and abundant foamy cells. The incidences of plaque rupture were 76% and 82%, thrombosis 81% and 91% respectively in 58 cases of UA and 22 cases of AMI, and the incidence of UA is statistically significant in comparing with that of the SA group (P < 0.001).

CONCLUSION

In SA group, stable plaque was the main finding, plaque rupture and thrombosis rare. While in UA and AMI patients, unstable plaques predominant with a high incidence of plaque rupture and thrombosis which were the leading cause of acute coronary events.