RT Journal Article SR Electronic T1 7 Dynamic changes of injured myocardium very early after acute myocardial infarction quantified using t1 mapping cardiovascular magnetic resonance technique JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP A8 OP A8 DO 10.1136/heartjnl-2018-BCVI.22 VO 104 IS Suppl 5 A1 Mohammad Alkhalil A1 Alessandra Borlotti A1 Giovanni Luigi De Maria A1 Lisa Gaughran A1 Jeremy Langrish A1 Andrew Lucking A1 Vanessa Ferreira A1 Rajesh K Kharbanda A1 Adrian P Banning A1 Keith M Channon A1 Erica Dall’Armellina A1 Robin P Choudhury YR 2018 UL http://heart.bmj.com/content/104/Suppl_5/A8.2.abstract AB Introduction Recent data have suggested that myocardial oedema followed bimodal pattern early post ST-segment elevation myocardial infarction (STEMI). Yet, there was disagreement between oedema quantified by cardiac magnetic resonance (CMR) imaging and tissue desiccation. Using highly-sensitive T1 mapping we sought to study the temporal changes in the extent and intensity of injured myocardium within one week post STEMI.Methods A first group (n=31) underwent three 3 T-CMR scans (time-point (TP) <3 hours, 24 hours and 6 days) using T1-mapping. A second group (n=17) had a single scan at 24 hours using both T1-mapping and T2-weighted sequences to assess the extent of area-at-risk (AAR) measured by these techniques.Results The mean T1 relaxation time value within the AAR of the first group was reduced after 24 hours (p<0.001 for TP1 vs TP2) and subsequently increased at 6 days (p=0.041 for TP2 vs TP3). However, the extent of AAR quantified using T1-mapping did not follow the same course, and no change was detected between TP1 and TP2 (p=1.0) but between TP2 and TP3 (p=0.019). In the second group where both T1-mapping and T2-weighted were compared, extent of AAR was significantly larger on T1-mapping (42%±15% vs 39±15%, p=0.025).Conclusion The intensity of oedema post-STEMI followed a bimodal pattern; while the extent of AAR did not track the same course. This discrepancy has implications for use of CMR in this context and may explain the previously reported disagreement between oedema quantified by imaging and tissue desiccation.