Assessment of longitudinal changes in strain using DENSE in patients with myocardial infarction

Methods 50 male patients (age 56 ± 10 years) underwent CMR on a 1.5T Siemens Avanto within 7 days of MI, and 47 returned for a follow-up scan after 6 months. The protocol included cine, DENSE (2D) and late gadolinium enhancement (LGE) imaging. Cine images were used to assess cardiac function by calculating LV ejection fraction (LVEF) and end-systolic volume (LVESV). DENSE and LGE were compared using a single mid-ventricular short-axis slice, which was analysed both as a whole slice and after division into 6 AHA segments. The percentage of each segment which contained LGE was calculated using a threshold of mean +5SD of remote myocardium intensity. DENSE images were analysed to obtain a value for peak circumferential strain (Ecc). Segments in the baseline scans were grouped according to the extent of LGE (non-infarcted, <50% infarcted, >50% infarcted), and the change in peak Ecc between baseline and follow-up was evaluated using a oneway ANOVA with Tukey’s post-hoc test. Individual patients were compared directly, and the correlations between change in strain and (i) change in LGE (segments) and (ii) change in cardiac function (slices) were assessed.