Prediction of infarct size by speckle tracking echocardiography in patients with anterior myocardial infarction

Abstract

Speckle tracking echocardiography (STE) is based on tracing of pixel groups in grayness scale for the quantitative measurement of myocardium strain and myocardium strain rate. Recent data suggest that evaluation of STE could be a tool for myocardial function assessment similar to MRI. To assess the predictive value of STE for the evaluation of infarct size in patients with anterior ST-elevation myocardial infarction (STEMI). We enrolled 39 patients with the first anterior wall STEMI (mean age 59±10 years, 29 men). All patients were treated with a primary percutaneous coronary intervention, and the time from the symptom onset to reperfusion was 298±195 min. Left ventricular ejection fraction assessed in three-dimensional echocardiography was 47±9%. On the day of discharge, STE was performed to determine the average global value of peak longitudinal strain (GLS) of 16 myocardial segments. The average value of the peak longitudinal strain for nine segments supplied by the left anterior descending artery anterior wall global longitudinal strain was assessed separately. Infarct size was assessed 3 months after STEMI by MRI using late gadolinium enhancement, and a large infarct was defined as at least 20% left ventricle myocardium covered by the scar. According to the results of MRI, we defined two groups: 22 patients with a large infarct (≥20%, group A) and 17 patients with a small infarct (<20%, group B). There were no differences between both groups in the demographics and cardiovascular risk factors. There was a significant correlation between GLS and the degree of myocardium injury assessed by MRI (r=0.62, P=0.001). The correlation was higher for anterior wall global longitudinal strain (r=0.68, P=0.001). With the receiver operating characteristic curve, the cut-off point for GLS was calculated (-12.3), which defined a large infarct with 82% sensitivity and 87% specificity (area under the curve=83). For segments supplied by the left anterior descending artery, the cut-off value for the prediction of a large infarct was -11.5 (sensitivity 90%, specificity 73%, area under the curve=84). STE seems to be a very promising tool in the prediction of infarct size in patients with anterior STEMI.