Background: Echocardiography is widely used to assess left ventricular (LV) thrombus after acute myocardial infarction (AMI). However, this detection may be particularly difficult in the case of suboptimal acoustic windows, even though wide use of second harmonic imaging (SHI) has significantly improved the imaging quality of echocardiography. Contrast echocardiography has recently been introduced in routine practice with new contrast agents, and dramatically improves the quality of echocardiographic imaging. The aim of this study was to determine the value of contrast echocardiography for the detection of apical LV mural thrombus in a population of pts presenting with anterior AMI.

Methods: Fifty consecutive pts referred to our coronary care unit for anterior AMI with ST-segment elevation and underwent coronary arteriography, left ventricular (LV) angiography and revascularization procedure. At day 7, a transthoracic echocardiographic study was systematically performed using fundamental imaging (FI), SHI and contrast agents for the assessment of LV chamber. All LV chamber assessments were performed blindly and independently by 2 observers (1 experienced physician and 1 physician-trainee). Each observer determined the presence or the absence of LV thrombus or the impossibility to conclude (doubt).

Results: Mean LVEF was 44 ± 9% (range 28% to 60%). Six pts (12%) presented with a confirmed LV mural thrombus. Mean time to revascularization and mean LV ejection fraction in pts with LV mural thrombus were 6.3 ± 1.8 hours and 31.5 ± 2.8% respectively, vs. 2.9 ± 1.4 hours and 46.7 ± 8.5% in pts without thrombus (p = 0.01 and p = 0.0004, respectively). Thirty-five per cent of pts with time to revascularization > 3 hours presented with a LV mural thrombus vs. 0 patient when time to revascularization was < = 3 hours (p = 0.003). The most accurate method for detecting LV mural thrombus was the contrast echocardiography, whatever the experience of the physician. For observer 1, an accurate diagnosis was performed in 86%, 92% and 100% of pts, respectively using FI, SHI and contrast agent (p = 0.03). For observer 2, an accurate diagnosis was performed in 80%, 86% and 100% of pts, respectively using FI, SHI and contrast agent (p = 0.005). No patient with a misdiagnosis of thrombus had an optimal acoustic window using FI or SHI.

Conclusion: Pts presenting with anterior AMI could benefit from contrast echocardiography for the assessment of LV mural thrombus when acoustic windows are suboptimal and time to revascularization is > 3 hours.