Myocardial infarct size for predicting improvements in cardiac function in patients with ischemic cardiomyopathy following coronary artery bypass grafting.

Background: This study used late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) to assess myocardial infarct size, with the data being employed to predict whether patients with ischemic cardiomyopathy (ICM) would experience improvements in left ventricular function at 6 months following coronary artery bypass grafting (CABG). Methods: The data of patients with ICM with left ventricular ejection fraction (LVEF) ≤40% who underwent CABG were retrospectively analyzed. All patients underwent preoperative LGE-CMR imaging. Echocardiography results from 6 months post-CABG were used to assess improvements in LVEF, with improvement being defined as ΔLVEF ≥5%. The value of myocardial infarction segments and infarct size as predictors of improved cardiac function following CABG was analyzed. Results: Of the included patients, 66.7% (52/78) exhibited improved cardiac function at 6 months post-CABG. LGE-CMR imaging data revealed that compared to improved group, the improved group had significantly more myocardial infarct segments [improved group: median 1.0, interquartile range (IQR) 0-3; nonimproved group: median 4.0, IQR 3.0-6.0; P<0.001] and significantly greater myocardial infarct size (improved group: 22.4%±8.2%; nonimproved group: 34.7%±5.9%; P<0.001). The area under the receive operating characteristic curve values for myocardial infarct size in predicting cardiac function improvement were significantly higher than those of myocardial infarct segments (0.88 Conclusions: Myocardial infarct size can be measured to reliably predict improvements in cardiac function in patients with ICM following CABG. These results can guide clinicians in their efforts to identify those patients most likely to achieve positive outcomes following CABG.