Comparison of wall thickening and ejection fraction by cardiovascular magnetic resonance and echocardiography in acute myocardial infarction.

OBJECTIVES: The purpose of this study was to compare cardiovascular magnetic resonance (CMR) and echocardiography (echo) in patients treated with primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) with emphasis on the analysis of left ventricular function and left ventricular wall motion characteristics.

METHODS: We performed CMR and echo in 52 patients with first AMI shortly after primary angioplasty and four months thereafter. CMR included cine-MR and T1-weighted first-pass and late-gadolinium enhancement (LGE) sequences. Global ejection fraction (EF(CMR), %) and regional left ventricular function (systolic wall thickening %, [SWT]) were determined from cine-MR images. In echo the global left ventricular function (EF(echo), %) and regional wall motion abnormalities were determined. A segment in echo was scored as "infarcted" if it was visually > 50% hypokinetic.

RESULTS: EF(echo) revealed a poor significant agreement with EF(CMR) at baseline (r: 0.326; p < 0.01) but higher correlation at follow-up (r: 0.479; p < 0.001). The number of infarcted segments in echocardiography correlated best with the number of segments which showed systolic wall thickening < 30% (r: 0.498; p < 0.001) at baseline and (r: 0.474; p < 0.001) at follow-up. Improvement of EF was detected in both CMR and echocardiography increasing from 44.2 +/- 11.6% to 49.2 +/- 11% (p < 0.001) by CMR and from 51.2 +/- 8.1% to 54.5 +/- 8.3% (p < 0.001) by echocardiography.

CONCLUSION: Wall motion and EF by CMR and echocardiography correlate poorly in the acute stage of myocardial infarction. Correlation improves after four months. Systolic wall thickening by CMR < 30% indicates an infarcted segment with influence on the left ventricular function.