ABSTRACT
OBJECTIVES: The aim of this study was to investigate the morphologic changes in infarct-related lesions after stenting in acute or recent myocardial infarction (MI) with coronary angioscopy. BACKGROUND: There is no information on the serial morphologic changes, which occur after stenting, and the time course of neointimal coverage of stents for disrupted unstable plaques. METHODS: Forty-three patients with MI within seven days of onset were examined. Angioscopy was serially performed for the infarct-related lesions at baseline (n = 43), after balloon angioplasty (n = 35), and after stenting following balloon angioplasty (n = 39) and at one (n = 36) and six months (n = 30) after stenting. RESULTS: At baseline, most of the lesions had complex morphology, yellow plaque color, and protruding thrombus (96%, 96%, and 74%, respectively). Although balloon angioplasty reduced the protruding thrombus, it remained in 37%, and an intimal flap was observed in 89% of the lesions. After stenting, the protruding thrombus and intimal flap disappeared, with an increased luminal size obtained in all lesions. At one-month follow-up, an irregular and yellow surface, along with a lining thrombus, was still observed, with partial neointimal stent coverage in most of the lesions. At six-month follow-up, the neointima was found to have sufficiently formed over the stent. The plaque shape and color were almost all classified as smooth (97%) and white (93%). CONCLUSIONS: These results suggest that a stent not only compressed and covered a disrupted plaque with a protruding thrombus and intimal flap, leading to a wide vessel lumen, but also helped to seal the unstable plaque through neointimal proliferation.
