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

Abstract

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, echo-cardiographic 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 = 0.03), 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 = 0.01) and high peak creatine kinase level (beta = 5.17, P = 0.046). Thrombus disappeared in 11/30 (36.7%) patients during one-year echo-cardiographic 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.