Post-myocardial infarction late diastolic left ventricular blood flow energetics are independently associated with left ventricular remodeling

Abstract

Abstract Background Post-myocardial infarction (MI) left ventricular (LV) remodeling emerges as a compensatory mechanism and leads to complex pathophysiological changes in LV blood flow hemodynamics. The interplay, if any, between LV blood flow energetics and remodeling remains unknown. We hypothesized that LV blood flow energetics early after MI are independently related to the temporal changes in LV end-diastolic volume (LVEDV). Methods In this prospective cohort study, 69 patients with acute re-perfused ST-segment elevation MI (STEMI) were included. The patients underwent cardiovascular magnetic resonance (CMR) examination within 2 days of the index event and at 3-month. CMR examination included cine, late gadolinium enhancement, and whole-heart 4D flow acquisitions. LV volume-function, infarct size (indexed to body surface area), microvascular obstruction (MVO), mitral inflow, and 4D blood flow kinetic energy (KE) characteristics were obtained. LV mean and peak KEi (indexed to LVEDV) were quantified for all time parameters (entire cardiac cycle, during systole/diastole, at E- and A-waves). Results In univariable linear regression analysis, peak KEi (R-R interval), mean systolic KEi, A-wave KEi, MVO presence were all associated with the relative change (%) of LVEDV (p=0.03, p=0.01, p<0.01, P=0.03, respectively). In multivariable linear regression analysis, A-wave KEi was identified as the only independent marker for association with the relative change of LVEDV (p=0.02). In another univariable linear regression analysis, A-wave KEi, infarct size, and MVO presence were all associated with the absolute change of LVEDV (p=0.03, p=0.04, p=0.04, respectively). In multivariable linear regression analysis, A-wave KEi was determined as the only independent marker for association with the absolute change of LVEDV (p=0.02). No significant association was observed between mitral inflow characteristics and relative and absolute change of LVEDV. Conclusion Late diastolic LV blood flow energetics early after acute MI are independently associated with both absolute and relative longitudinal changes in LVEDV and may provide incremental value over infarct and mitral inflow characteristics to be associated with post-MI LV remodeling. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation