Page 83 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

with imaging techniques such as single-photon emission computed tomography and
late gadolinium contrast enhanced cardiovascular magnetic resonance.21,22,23 Large
areas of myocardial infarction are associated with impaired LVEF. In a study of 378
patients with STEMI treated with primary PCI, peak troponin levels showed a good
sensitivity to predict a reduced LVEF ≤40% at 5-day and 30-day follow-up.5 The present
study showed an independent association between high peak troponin levels and lack
of LVEF recovery at 6 months follow-up. Furthermore, the presence of multi-vessel
disease and the use of complete revascularization versus PCI of only the infarct-related
artery may impact on the LV functional recovery. In a previous article of our STEMI 4 cohort. Dimitriu-Leen et al showed that the presence of myocardial ischemia at 3 months
after PCI was associated with more impaired LV systolic function.24 However, baseline LVEF is also an important determinant of the improvement in LV systolic function at follow-up. LVEF is strongly associated with myocardial infarct size: a low LVEF reflects larger damage that may not recover at follow-up. Oh et al investigated predictors of LV functional recovery (LVEF ≥45%) in 1307 patients after myocardial infarction (STEMI; n=913 and non-STEMI; n=394).25 In a multivariable model, individuals with a baseline LVEF (≥30 and <45%) had higher probability (OR 1.73; p=0.013) of improvement in LVEF ≥45% after a median follow-up of 208 days as compared to patients with a baseline LVEF <45% (n=644). These data are similar to the current findings where baseline LVEF was also independently associated with full recovery of LVEF at 6 months follow-up.
In addition, loading conditions influence the LV remodeling process after STEMI. Ischemic mitral regurgitation is a post-infarct complication that may occur in up to 64% of patients.26 In a large contemporary STEMI population (N=1599), Abate et al reported a prevalence of 40% for ischemic mitral regurgitation in which 6% showed moderate and severe mitral regurgitation after STEMI.27 The LV volume overload imposed by mitral regurgitation may lead to larger LV volumes and more impaired LVEF preventing LV functional recovery.
How guideline-based medication influences LVEF recovery at follow-up has not been studied extensively in STEMI patients treated with primary PCI. Previous studies including only STEMI patients have reported lower usage of ACEi, ARB-II and beta- blockers.17,20 In the present study, including a large population homogeneously treated in terms of ACEi, ARB-II and beta-blockers, an independent association between the use of these therapies and LVEF recovery was not observed. This underscores the importance of systematic approach of patient care following prevailing guidelines which is currently strongly advocated.
77