Abstract 18808: Two-dimensional Speckle-tracking Echocardiography to Assess the Viability of Acute Myocardial Infarction

Abstract

BACKGROUND [[Unable to Display Character: ―]]Increasing infarct extent is associated with impaired prognosis after acute myocardial infarction (AMI). Two-dimensional speckle-tracking echocardiography (2DSTE) enables the assessment of myocardium deformation and identifies the amount and transmural distribution of viable myocardium. The objective of the study was to evaluate the predictive value of 2DSTE for improvement in cardiac function after AMI in comparison with contrast-enhanced cardiac magnetic resonance imaging (ceMRI). METHODS and RESULTS [[Unable to Display Character: ―]]In 25 patients with first-time acute ST elevation myocardial infarction, myocardial viability was assessed using 2DSTE and ceMRI to predict recovery of function at 6 months follow-up. For each left ventricular segment in a 16-segment model, peak radial, circumferential and longitudinal strain was determined using 2DSTE, and the relative extent of hyperenhancement using ceMRI. Of 128 segments with impaired function early after AMI, 65 showed regional recovery. Compared with segments showing functional improvement, those that failed to recover had lower peak radial (18 ± 16 % vs. 34 ± 23 %; p < 0.001), circumferential (-8 ± 5 % vs. -18 ± 7 %; p < 0.001) and longitudinal (-9 ± 5 % vs. -13 ± 5 %; p < 0.001) strain and a greater extent of hyperenhancement (71 ± 21% vs. 25 ± 20%; p < 0.001). Among strain parameters, circumferential strain yielded greater area under the curve (0.914) than radial and longitudinal strain (0.717 and 0.743, respectively). The predictive value of circumferential strain (sensitivity 83.1%, specificity 81.2%, at a cutoff value of -12.5%) could be comparable to that of hyperenhancement by ceMRI (sensitivity 87.8%, specificity 88.1%, area under the curve 0.939, at a cutoff of 46% hyperenhancement) (p=0.44). CONCLUSIONS [[Unable to Display Character: ―]]Circumferential strain by 2DSTE is a powerful novel parameter to identify reversible myocardial dysfunction after AMI.