[Angiogenesis in coronary atherosclerotic plaques and its relationship to plaque stabilization].

Objective: To compare the angiogenesis in unstable and stable plaques and to investigate the potential role of neovessels in creating vulnerable sites for atherosclerotic plaques.

Methods: Specimens of coronary arteries were obtained from 52 autopsy cases with acute coronary syndromes. Plaque morphology was studied by use of stained slides. 922 tissue blocks of late-stage lesions were classified into two groups: (1) unstable plaque (n = 153), the plaque was characterized by a large extracellular lipid core (more than 40% of the plaque area); (2) stable plaque (n = 769), lipid core less than 40% of the plaque area. Forty blocks were selected randomly from each group and serial sections were stained immunohistochemically with a polyclonal antibody against F VIII RAg. Computer-aided planimeter was used for quantitative analysis.

Results: In unstable plaques, the occurrence of neovessels was more frequent and the neovessel density (number/mm(2)) was significantly increased as compared to that of stable plaques (frequency: 80.4% vs 66.6%, P < 0.01; shoulder: 22.16 +/- 19.96 vs 10.04 +/- 11.52, base: 21.68 +/- 20.44 vs 9.68 +/- 11.52, fibrous cap: 3.80 +/- 5.32 vs 1.48 +/- 2.28, P < 0.05). Most neovessels were located in the shoulder region and at the base of plaques.

Conclusions: These findings suggest that neovessels in coronary atherosclerotic plaques are closely associated with the decreased stabilization of the plaques.