30 Relationship between LV flow kinetic and myocardial deformation in chronic infarction using CMR flow kinetic energy and feature tracking

Introduction The exact mechanism underlying myocardial maladaptive changes post-ST elevation myocardial infarction (STEMI) remains unclear. We aim to assess the impact of the tissue-flow interaction on the development of adverse cardiac remodelling 12 months (M) after acute STEMI. Materials and Methods 49 first STEMI patients (M:F= 36:13; mean age = 58 ± 10) prospectively underwent 3T CMR acutely, 3 and 12 M post-STEMI. The CMR protocol included LV cine-images, 4D flow, late gadolinium enhancement (LGE) imaging. The outcome measures at 3M included: LV flow kinetic energy (KE) and 4D flow parameters indexed to end-diastolic volume (KEiEDV ) and 4D FlowiEDV [LV-KEiEDV, Minimal-KEiEDV, In-plane-KEiEDV, Systolic-KEiEDV, Diastolic-KEiEDV, and Residual LV-VolumeiEDV, Retained LV-inflowiEDV, Delayed LV-ejection flowiEDV, Direct LV-flowiEDV); global radial, circumferential and longitudinal strain (GRS, GCS, GLS) by feature tracking (FT), infarct size (IS). Adverse LV remodelling (LVremod) was defined by a 20% increase in LVEDVi at 12M from baseline, in opposition to the non-remodelling group (LVnon-remod). Results There were 23 LVremodpatients.(table 1). LVremodpatients had significantly altered FT, systolic and inplane KEiEDV, direct and residual 4D FlowiEDV. In the LVremod group, there was a significant correlation between direct LV-flowiEDV and GRS (r= 0.6, p=0.002), GCS (r= -0.7, pEDV and GRS (r= -0.6, p=0.002), GCS (r= 0.7, pDiscussion Our results show that in LVremodpatients, the reduction in EF and FT strain at 3M correlated significantly with a change in intracavitary systolic kinetic energy and flow which were not depicted by stroke volume, suggesting an early interaction between FT, KE and 4D flow parameters at 3M post STEMI in the LVremod group. Conclusion The interplay between LV mechanistic and flow kinetic at 3 months post-acute MI leading to adverse remodeling at 12 months involves significant alteration of FT,4D flow and systolic KE parameters. These parameters could help for further risk stratification for the development of adverse remodeling at 12 months post-acute MI. Acknowledgements