Quantitative Evaluation of Myocardial Strain After Myocardial Infarction with Cardiovascular Magnetic Resonance Tissue-Tracking Imaging

To investigate the value of cardiovascular magnetic resonance tissue-tracking (CMR-TT) imaging in the differentiation of subendocardial and transmural myocardial infarction (MI) and determine whether strain parameters are enable to detect adverse left ventricular (LV) remodeling.Global peak circumferential, longitudinal, and radial strains (GPCS, GPLS, GPRS) and segmental peak circumferential, longitudinal, and radial strains (PCS, PLS, PRS) in accordance with the 16-segment model were all derived. All positive segments were divided into two groups according to transmural degree. All patients were dichotomized in accordance with the existence of LV remodeling, which was defined as infarct size (IS) > 24%.Patients with MI showed significant lower GPRS, GPCS, and GPLS than the control group (16.41% ± 8.92%, -8.77%± 3.51%, -7.54% ± 2.43% versus 32.41% ± 12.99%, -14.92% ± 3.32%, -11.50% ± 2.51%). Lower PRS [3.25% (-5.57, 7.835) versus 19.94% (12.50, 30.75), P < 0.001] and PCS (-3.81 ± 4.60% versus -8.97± 4.43%, P < 0.001) can be found in transmural infarcted segments compared to subendocardial infarcted segments. PLS between transmural and subendocardial infarcted segments (-4.03% ± 4.88% versus -4.34% ± 4.98%), without however statistical significance (P = 0.523). The optimal cutoff value for PRS in the discriminate diagnosis of MI was 8.97% with a sensitivity of 81.8% and specificity of 98.0%. The optimal cutoff value for PCS was -7.56% with a sensitivity of 83.6% and specificity of 72.1%. Receiver operating characteristic (ROC) analysis revealed an optimal cutoff GPRS of 15.45%, and GPCS of -6.72% yielded high diagnostic accuracy in the identification of remodeling, which was higher than left ventricular ejection fraction (LVEF).CMR-TT can differentiate between subendocardial and transmural infarction and detect LV remodeling, and the diagnostic value was superior to conventional functional parameters.