Contrast-enhanced computed tomographic and echocardiographic detection of intra-aortic floating thrombus causing acute myocardial infarction.

We present the rare case of a 51-year-old man with acute myocardial infarction (AMI) caused by left main coronary artery (LMCA) occlusion due to intra-aortic thrombus. He arrived at our hospital with sudden left precordial oppression. Transcatheter coronary angiography for suspected AMI detected no coronary lesions. After 10 minutes, noncontrast computed tomography (CT) confirmed significantly high transmural attenuation areas suggesting myocardial infarction in the septal, anterior and lateral wall. Contrast-enhanced CT and transesophageal echocardiography detected a small mass near the ostium of the LMCA in the coronary sinus of Valsalva. We thus considered that the mass occluded the LMCA, which led to AMI. A stent was implanted to prevent the mass from sealing the LMCA ostium, but the patient died of sepsis. A post-mortem examination clarified that the mass was a red thrombus attached to an erosive and atherosclerotic aortic wall.