IDENTIFICATION OF CORONARY THROMBUS AFTER MYOCARDIAL-INFARCTION BY INTRACORONARY ULTRASOUND COMPARED WITH HISTOLOGY OF TISSUES SAMPLED BY ATHERECTOMY

This study compares the ability of intracoronary ultrasound (ICUS) to identify thrombus by means of actual criteria, with the histologic stu dies of tissues removed by directional atherectomy in patients treated previously with thrombolytic therapy, Coronary angiography and intrav ascular ultrasound imaging were performed before atherectomy in 34 pat ients who had received intravenous thrombolytic therapy for acute myoc ardial infarction a mean of 6 days before, The lesion morphology and t he percentage of stenosis were defined on the angiogram, The ultrasoun d characteristics of the narrowing were described as intraluminal thro mbus, mural mixed plague, and dense plague, Thirty patients were studi ed, Thrombus was suspected in 8 on angiography, By ICUS, the presence of thrombus predicted in 21 patients, Histologic studies of excised ti ssues found thrombus in 20 of the 30 patients, When ICUS was compared with histology, the true-positive rate was 80% and the false-positive rate was 50%; the true-negative rate was 50% and the false-negative ra te was 20%, The correlation between observers was high, These observat ions suggest that ICUS may be useful in identifying fresh thrombus, Th e findings of this study help to confirm the criteria for diagnosing i ntraluminal thrombus by ICUS imaging.