The embolic risk and changes of
thrombus location and size were investigated in 29 consecutive patients with echocardiographically proven thrombi in the left atrium. Inclusion criteria were the visualization of a left atrial
thrombus using transesophageal echocardiography. Transesophageal follow-up echocardiograms were performed at a mean period of 18 months. In this period 6 cases of
embolism were observed at an interval of 20 days to 26 months after the detection of
thrombus. Thus, the embolic rate was 14% per patient year. All patients received
phenprocoumon (n = 4) or
aspirin at the time of
embolism. Furthermore, in two patients after cardiac
thrombectomy left atrial thrombi were seen again although patients were treated with
anticoagulants. On the other hand, in 12 patients (5 received oral anticoagulation, 2 received
aspirin) thrombi completely resolved. It can be concluded from these data, that the majority of patients receiving anticoagulation profit from this
therapy, however, a complete protection against arterial
embolism or reoccurrence of thrombi cannot be reached. Left atrial spontaneous echo contrast was the only risk factor significantly associated with
thromboembolism in patients with left atrial thrombi.