Peak CK-MB has a strong association with chronic scar size and wall motion abnormalities after revascularized non-transmural myocardial infarction-A prospective CMR study

Background: Large myocardial infarction (MI) is associated with adverse left ventricular (LV) remodeling (LVR). We studied the nature of LVR, with specific attention to non-transmural MIs, and the association of peak CK-MB with recovery and chronic phase scar size and LVR. Methods: Altogether 41 patients underwent prospectively repeated cardiovascular magnetic resonance at a median of 22 (interquartile range 9-29) days and 10 (8-16) months after the first revascularized MI. Transmural MI was defined as ≥75% enhancement in at least one myocardial segment. Results: Peak CK-MB was 86 (40-216) μg/L in median, while recovery and chronic phase scar size were 13 (3-23) % and 8 (2-19) %. Altogether 33 patients (81%) had a non-transmural MI. Peak CK-MB had a strong correlation with recovery and chronic scar size (r≥0.80 for all, r≥0.74 for non-transmural MIs; p<0.001). Peak CK-MB, recovery scar size, and chronic scar size, were all strongly correlated with chronic wall motion abnormality index (WMAi) (r≥0.75 for all, r≥0.73 for non-transmural MIs; p<0.001). There was proportional scar size and LV mass resorption of 26% (0-50%) and 6% (-2-14%) in median. Young age (<60 years, median) was associated with greater LV mass resorption (median 9%vs.1%, p=0.007). Conclusions: Peak CK-MB has a strong association with chronic scar size and wall motion abnormalities after revascularized non-transmural MI. Considerable infarct resorption happens after the first-month recovery phase. LV mass resorption is related to age, being more common in younger patients.