Incidence, diagnostic methods, and evolution of left ventricular thrombus in patients with anterior myocardial infarction and low left ventricular ejection fraction: a prospective multicenter study

Background and objectives We aimed to assess the incidence and evolution of left ventricular (LV) thrombi in a high-risk population of patients with LV systolic dysfunction after anterior myocardial infarction (ant-MI). We also compared the accuracy of transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging with contrast-delayed enhancement (CMR-DE) in detecting LV thrombi. Methods We prospectively included 100 consecutive patients with LV ejection fraction (LVEF) b45% at the first TTE performed <7 days after ant-MI. A second evaluation with TTE and CMR-DE (by blinded examiners) was performed at 30 days. A third TTE and assessment of clinical status were performed between 6 and 12 months after ant-MI. Results Patients (males 71%; mean age 59.1 +/- 12.1 years; mean LVEF 33.5% +/- 6.0%) were included at a median of 5.5 days (interquartile range 25th-75th percentile 4.25-6.0 days) after ant-MI. Thrombi were detected among 26 (26%) patients at a median of 12.0 days after ant-MI (7 patients at 1-7 days after MI; 15 at 8-30 days; and 4 after day 30). Sensitivity and specificity for LV thrombi detection were 94.7% and 98.5%, respectively, for TTE as compared withCMR-DE. Most thrombi (n = 24; 92.3%) disappeared after triple antithrombotic therapy (vitamin K antagonist in addition to dual antiplatelet therapy). Conclusion Left ventricular thrombus is a frequent complication after ant-MI with systolic dysfunction. When a search for thrombus is prespecified, the accuracy of TTE is high as compared with CMR-DE. The best antithrombotic strategy is not known.