Predictors of left ventricular thrombus formation and disappearance after anterior wall myocardial infarction

AIMS: This study sought to determine predictors of left ventricular thrombus formation and resolution after acute anterior wall myocardial infarction. METHODS AND RESULTS: We have analysed clinical, echocardiographic and angiographic data in 53 consecutive patients with anterior myocardial infarction. Two-dimensional and Doppler echocardiographic examinations were performed on days 1, 2, 3 and 7, after 3 and 6 weeks, and 3, 6, and 12 months following infarction. Coronary angiography was performed in 44 patients before hospital discharge. Left ventricular thrombus was detected in 30/53 patients (29/30 in the first week after infarction). Univariate analysis showed that left ventricular thrombus formation was associated with a higher initial end-systolic volume index (beta = 0.04, P = 0.001), and end-diastolic volume index (beta = 0.03, P = 0.03), a larger infarct perimeter (beta = 0.02, P = 0.01), a lower initial ejection fraction (beta = 0.06, P =0.001), a higher initial wall motion score index (beta = 1.75, P = 0.023), a higher peak creatine kinase level (beta = 3.90, P = 0.01), Killip class >1 (beta = 1.11, P = 0.003), infarct expansion (beta = 0.78, P = 0.04), occluded infarct-related artery (beta = -0.87, P = 0.04) and non-thrombolytic therapy (beta = -0.76, P = 0.047). According to the Cox proportional regression model, independent predictors of thrombus formation after anterior myocardial infarction were high end-systolic volume index (beta = 0.06, P = 0.001) and high peak creatine kinase level (beta = 5.17, P = 0.046). Thrombus disappeared in 11/30 (36.7%) patients during one-year echocardiographic follow-up. The only independent predictor of thrombus disappearance after acute myocardial infarction was the absence of apical dyskinesis 6 weeks after infarction (beta = -1.53, P = 0.045). CONCLUSIONS: Our data demonstrate that the best predictor of left ventricular thrombus formation after acute anterior myocardial infarction is a high initial end-systolic volume. Thrombus resolution is more likely to occur in patients without apical dyskinesis at the end of the healing phase of infarction.