Dynamic changes in myocardial architecture after reperfused acute myocardial infarction (AMI): insights from the prospective REMI study (REmodeling after Myocardial Infarction)

Methods 66 consecutive patients who fulfilled inclusion criteria underwent two CMRs: 2-4 days (baseline) and 6 months (follow-up) after the AMI, comprising SSFP images for analysis of left ventricular functions and late gadolinium enhancement (LGE) MRI (0.1 mmol/Kg; DOTAREM, GUERBET, Roissy, France) for infarct analysis using a threshold method. Of 132 CMRs, 6 (4 from baseline) were non-diagnostic owing to poor EKG triggering and/or inability of the patients to hold their breath; 5 patients without evidence of infarct scar by LGE were also excluded. Hence, 57 patients (50 male; 56.7 ± 13.2 yo) were eventually analyzed. Total infarct was determined as area with signal intensity (SI) above mean+5SD of remote myocardium and was further divided into peri-infarct zone (PIZ) and infarct core by introducing a 7SD threshold; microvascular obstruction was manually included into the core; a core to PIZ ratio(C/PIZ) was calculated and a transmurality score was computed using a 5-point scale on the 16-segment model derived from the AHA model. Paired t-test was used for comparison between the two MRI and Pearson’s correlation coefficients were calculated to assess prediction of LV parameters.