Perspective:

Multiple previous smaller studies have demonstrated the diagnostic accuracy of CMR imaging for identification of LV thrombi. This study directly compared routine, clinically indicated transthoracic echocardiography for detection of LVT in 243 patients and suggested a definite superiority of CMR for this purpose. Certainly the multi-modality imaging aspect of CMR, including delayed enhancement as well as high resolution visualization of the entire endocardial surface area, would confer an advantage to CMR for detection of thrombi, although the poor performance of echocardiography in this study is somewhat surprising. It should be emphasized that the ultrasound platforms utilized here were one and two generations beyond current state of the art, and that contrast for LV opacification was used in only 4% of patients. Additionally, the overwhelming majority of studies were not done for specific evaluation of thrombus, and the degree to which a more targeted echocardiogram for thrombus would have resulted in a higher yield remains conjectural. The doubling of sensitivity in the very small number of patients for whom LVT was the clinical indication suggests a role for more dedicated imaging. In addition to comparing the diagnostic accuracy of the two techniques, the authors have provided follow-up for clinically relevant events suggesting embolization from a cardiac source. The fivefold greater event rate in patients with thrombus on DE-CMR compared to those without certainly suggests an enhanced accuracy and prognostic role for the technique. This compares to the only twofold increase of event rates when echocardiography was used to predict presence of thrombus. While the performance of echocardiography may be understated in this study related to concerns expressed above, the results of this work should certainly give a clinician concern for absolute reliance on echocardiography for diagnosis or exclusion of LVT.