To demonstrate the clinical value of left ventricular opacification (LVO) , compared to conventional echocardiography, on interpretation of apical thrombus, measuring left ventricular ejection fraction (LVEF), and monitoring the effects of anticoagulation.

This retrospective study included twenty-six myocardial infarction patients with suspected apical thrombus on routine echocardiography in China-Japan friendship hospital between August 2015 and October 2016. All patients underwent LVO using microbubble contrast agent (SonoVue). Six patients had repeated LVO examination 3-11 months after anticoagulant therapy. The diagnostic performance of routine echocardiography and LVO were compared using McNemar test. The interobserver agreement in measuring LVEF by conventional echocardiograph and LVO were analyzed using Bland-Altman analysis.

Apical thrombus were diagnosed in 6 patients, excluded in 4 patients and inconclusive in 16 patients by routine echocardiography, while diagnosed in 10 patients, excluded in 15 patients and inconclusive in 1 patients by LVO. The inconclusive results were significantly improved when using LVO [96.2%(25/26) vs 38.5%(10/26)] (χ²=13.067, P<0.001). Bland-Altman chart showed the mean difference of LVEF by LVO between senior and junior doctors was 1.5%[95% CI(-9.6%, 6.5%)], while the mean difference was 3.5% [95%CI(-23.9%, 16.9%)] when using routine echocardiography. The interobserver agreement in measuring LVEF was better for LVO. Six patients were followed up 3-11 months after anticoagulation. Of them, 1 thrombus disappeared, 4 diminished and 1 had no significant change.

LVO has the potential value of improving the diagnosis of apical thrombus, assessment of LVEF, and monitoring of anticoagulation in myocardial infarction patients.