Abstract 17644: Diagnostic Performance of Two-Dimensional Speckle Tracking Echocardiography for the Detection of Myocardial Infarction on Late Gadolinium Enhanced Magnetic Resonance Imaging

Abstract

Purpose: Two-dimensional speckle tracking echocardiography (2D-STE) permits non-invasive and accurate quantification of regional myocardial strain on left ventricle. We assessed the hypothesis that myocardial strain measured by 2D-STE can accurately diagnose the presence of myocardial infarction on late gadolinium enhanced magnetic resonance imaging (LGE MRI) in patients with coronary artery disease (CAD).

Methods: Seventy two patients with known or suspected CAD (mean age: 70±9 years) and 10 healthy volunteers (mean age: 29±5 years) were enrolled. In the patient study, longitudinal myocardial strains were quantified by using 2D-STE, and were compared with LGE MRI by using a 16-segment model. Receiver operating characteristics (ROC) analysis was performed to determine the diagnostic performance of longitudinal myocardial strain for detecting abnormal systolic contraction in the segments with LGE MRI. In the volunteer study, intra- and inter- observer reproducibilities of myocardial strain measurements were evaluated by calculating repeatability coefficients on Bland and Altman plot.

Results: Myocardial strain measurements by 2D STE were feasible on 1129 of 1152 (98%) segments. On LGE MRI, myocardial infarction was observed in 272 of 1152 (23.6%) segments. Significant difference of myocardial strain was observed between non-infarcted segments, infarcted segments with transmural extent (TE)≤50% and infarcted segments with TE>50% (-16.9±4.7, -13.1±4.4, -8.6±4.0, p<0.001 by ANOVA). On a segment based analysis, the area under the ROC curve of longitudinal strain by 2D-STE for detecting myocardial infarction was 0.87 (95% CI: 0.85-0.90). With a cut-off value of -13.9, sensitivity, specificity, PPV, NPV and accuracy of longitudinal myocardial strain for the detection of myocardial scar on LGE MRI were 86%, 77%, 54%, 95%, and 79% respectively. Intra- and inter- repeatability coefficients were 13.9 and 14.4% for strain measurement.

Conclusion: ROC analysis in this study indicated that assessment of longitudinal myocardial strain by using 2D-STE is useful for detecting segments with myocardial infarction on LGE MRI. High NPV of 95% suggest that strain measurement might be of great value for excluding segments with myocardial infarction.