Assessment of left ventricular function with magnetic resonance imaging vs. echocardiography, contrast echocardiography, and single-photon emission computed tomography in patients with recent ST-elevation myocardial infarction.

Aims: Magnetic resonance imaging (MRI) is often considered to be the gold standard in measuring left ventricular function and volumes. The aim of this study was to assess the agreements between standard echocardiography (standard echo), contrast echocardiography (contrast echo), single-photon emission computed tomography (SPECT), and MRI in the determination of left ventricular ejection fraction (EF) and end-diastolic volumes (EDV) in patients treated for acute ST-elevation myocardial infarction (STEMI).

Methods And Results: Standard echo, contrast echo, SPECT and MRI were performed on the same day, 3 months after STEMI in 150 patients participating in the NORwegian Study on District Treatment of ST-Elevation Myocardial Infarction (NORDISTEMI). Bland-Altman analysis of EF measured by all four imaging modalities showed generally low mean differences but wide limits of agreement. The mean EDV difference, however, was consistently higher when MRI was compared with standard echo (54.9 mL), contrast echo (41.7 mL) and SPECT (54.6 mL), and the limits of agreement were wider. The mean EDV differences between contrast echo vs. standard echo, SPECT vs. standard echo and contrast echo vs. SPECT were small.

Conclusion: Our data suggest that all four imaging modalities measured EF closely similar after STEMI as demonstrated by a very small bias. The limits of agreement were however wide. EDV measured by MRI was consistently higher when compared with the other methods which may be caused by different tracing-methods and imaging principles. As echocardiography is preferable from a cost-benefit point of view, further analysis would be needed to clarify the nature of such differences.