Long-term follow-up of left ventricular thrombus after acute myocardial infarction. A two-dimensional echocardiographic study in 96 patients.

To determine the incidence, natural history, and relation to anticoagulant therapy of left ventricular thrombus (LVT) following acute myocardial infarction (MI), we performed two-dimensional echocardiography in 96 consecutive patients with isolated MI during the acute episode and after four and 12 months. Only patients with anterior MI received oral anticoagulant therapy on admission and throughout the study period. The LVT was identified in 21/65 patients with anterior and in 1/31 patients with inferior MI. The large majority of LVT cases were seen for the first time during the acute phase of MI. LVT was associated with a significantly higher peak value of CK-MB (118 +/- 24 vs 76 +/- 35, p less than 0.001) and Killip class (2.5 +/- 0.8 vs. 1.5 +/- 0.7, p less than 0.002). Patients with anterior MI and LVT more frequently had segmental dyskinesia during acute MI than patients without LVT (86 percent vs 18 percent, p less than 0.001). In four patients LVT resolved during the study period. Discontinuation of anticoagulant therapy in four patients with an aneurysm led to LVT formation in three. Two patients suffered a clinically recognized embolic event; one never had LVT demonstrated by echocardiography. Thus, LVT usually develops in the early days following large anterior MI, complicated by pump failure and segmental dyskinesia, even when patients receive oral anticoagulant therapy. Surprisingly, the incidence of embolic events was low (1/22) in our LVT patients.