The purpose of this study was to evaluate intracoronary thrombi in
the culprit lesions in patients with acute myocardial infarction
(AMI) by angioscopy, and to compare them with clinical and
angiographic features. We angioscopically observed the culprit
coronary lesions in 66 patients with AMI (55 males and 11
females, 63.9±15.4 years old) just before interventional
therapy. Thrombi were observed in 42 of 66 lesions
(64%), namely, red thrombi in 16, mixed thrombi in 15,
white thrombi in 11. In patients with complete obstruction
(TIMI grade 0 and I), red thrombi were more frequently
observed than mixed or white thrombi. On the other hand, in
patients with incomplete obstruction (TIMI grade II and
III), white thrombi were more frequently observed than the
others. Angiographically, haziness and filling defect were
significantly more frequently observed in patients with red
thrombi than the others (p<0.05). The distance from
proximal side branch to thrombi tended to be longer in patients
with red thrombi than the others. The time from onset of AMI
tended to be longer in patients with white thrombi than the
others. These results suggest that blood flow may be an important
determinant of thrombi characterization.
