Clinical predictors of early left ventricular thrombus formation in acute myocardial infarction

OBJECTIVE: Clinical epidemiological and echocardiographic risk factors relating to the development of a left ventricular thrombus were studied retrospectively in patients with acute myocardial infarction. METHODS AND RESULTS: The data on 1833 consecutive patients treated for acute myocardial infarction during a 10-year period were processed retrospectively. Transthoracic echocardiography was performed on each patient 65.0 +/- 5.5 hours after hospital admission. A left ventricular thrombus was detected in 145 patients (7.9%). The patients with acute myocardial infarction and a left ventricular thrombus had significantly lower frequencies of 1) myocardial infarction in their family history (3% versus 11%, respectively), 2) hospital admission within 24 hours from the onset of chest pain (17% versus 50%, respectively), 3) thrombolytic therapy (8% versus 23%, respectively) and 4) current smoking (24% and 35%, respectively) than those without a left ventricular thrombus. In contrast, anterior infarction (81% versus 38%, respectively), left ventricular dilatation (30% versus 19%, respectively), dyskinesis of the left ventricular wall (23% versus 10%, respectively), an aneurysm (22% versus 7%, respectively) and a reduced systolic left ventricular function (ejection fraction < 40%) (28% versus 17%, respectively) were more frequent in the presence of a left ventricular thrombus after myocardial infarction. Multivariate analysis of the results revealed that the presence of anterior myocardial infarction and an aneurysm is associated with significantly increased hazard ratios. On the other hand, early hospitalization and a positive family history of infarction significantly lowered the hazard ratio. The frequency of a left ventricular thrombus was significantly higher in spring and winter. CONCLUSIONS: The results presented in this paper confirm the significant hazard of certain parameters [location of infarction (anterior) and aneurysm] as concerns left ventricular thrombus formation among patients with acute myocardial infarction. Early hospitalization was found to lower the risk of thrombus formation.These echocardiographic and clinical parameters may be useful in the establishment of the individual risk of intracavital thrombus formation and may be of help in everyday medical practice.