Morphologic changes in infarct-related plaque after coronary stent placement: a serial angioscopy study.

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.

[Clinical significance of plasma concentration of macrophage colony-stimulating factor in patients with vasospastic angina].

OBJECTIVES: The concentration of macrophage colony-stimulating factor (M-CSF), an inflammatory cytokine, increases with the progression of coronary lesions, but no clinical investigations have evaluated the relationship to coronary vascular tone. The present study investigated the relationship between M-CSF and vasoreactivity of the coronary arteries in patients with vasospastic angina. METHODS: Vasospastic angina (VSA) was characterized by transient chest pain and ischemic ST segment changes at rest, or by a positive result in spasm provocation testing with acetylcholine. The subjects were 24 patients with stable VSA(inactive VSA group) treated on an outpatient basis, 31 VSA patients hospitalized with unstable angina (active VSA group), and 13 healthy subjects(control group). The sensitivity of determination of plasma M-CSF in blood was 40 pg/ml. The levels of this factor in each group were compared. Based on the findings of the acetylcholine vasospasm-induction test, patients were divided into those with single-vessel vasospasm and those with multivessel vasospasm, and, according to the dose of acetylcholine required to induce spasm, into high- and low-dose groups. Plasma M-CSF levels in each group were compared. RESULTS: Mean plasma M-CSF was 598 +/- 180 pg/ml in the inactive VSA group, 775 +/- 194 pg/ml in the active VSA group, and 632 +/- 103 pg/ml in the control group. The mean plasma M-CSF level in the active VSA group was significantly higher than that in the inactive VSA group(p < 0.01). Mean plasma M-CSF level in the single-vessel and multivessel vasospasm groups was highest for active VSA patients with multivessel vasospasm (872 +/- 173 pg/ml). The relationship with the acetylcholine induction dose clarified that plasma M-CSF levels were highest in patients with active VSA in the acetylcholine low-dose group (825 +/- 177 pg/ml, p < 0.001). CONCLUSIONS: Plasma M-CSF concentration reflects the vasoreactivity of coronary spasm in the VSA group, and may be an indicator of the severity of coronary endothelial dysfunction.

Visualized plaque debris as a cause of distal embolization after percutaneous coronary intervention in patient with unstable angina.

Procedural complications of percutaneous transluminal coronary angioplasty for unstable angina are higher than for stable angina. We report a case in which coronary angioscopy proved the dislodgment of a large plaque fragment after Cutting Balloon angioplasty and confirmed our suspicion that plaque fragmentation can cause distal embolization.