Prevalence of Micro Vascular Obstruction and Major Adverse Cardiac Events by Echocardiography in Patients with STEMI after Reperfusion Therapy Compared with CMR

Abstract
Background: Ischemic heart disease is nowadays the leading cause of morbidity and mortality in the western world. Accurate detection and evaluation of this disease are of major importance. Cardiac magnetic resonance imaging (CMR) has an increasing role in the detection and evaluation of ischemic heart disease, and can be used to measure global and regional myocardial function, the presence of ischemia and myocardial scar tissue.
Aim of Study: The primary aim of this study is to compare the CMR with the Echocardiography (Echo) in evaluating occurrence of micro vascular obstruction and major adverse cardiac events within one month of revascularization.
Material and Methods: The study was carried out at the National Heart Institutes during the period from 1st of October 2016 till 1st of October 2017. Twenty patients were included in the study with documented ST segment elevation myocardial infarction (STEMI) and underwent reperfusion with primary percutaneous coronary intervention (PCI).
All patients are subjected to history, laboratory investiga-tion, Electrocardiogram (ECG), ECHO, revascularization by primary PCI, CMR and another Echo after revascularization.
Results: There was highly statistically significant relation between patients with Microvascular obstruction (MVO) and occurrence of major advance cardiac events (MACE) as all patients with MVO had MACE (p-value <0.001), while only 6% of the patients without MVO had MACE. After revascu-larization, 4 patients had MVO (20% of the study population), while MACE occurred in 5 patients (25% of the study popu-lation). There were statistically significant relation between score index (SI) and Ejection Fraction (EF) before and after revascularization (p-value <0.001) with mean score index before 1.27-}0. 15 and after 1. 13-}0.09 while mean EF before 52.80-}5.55 and after 57.80-}4.46.
After revascularization there were significant difference between score index by ECHO and that by CMR (p-value= 0.035) while no significant difference measured between EF by ECHO and that by CMR.
Before revascularization only EF has significant correlation with MVO, patients without MVO had mean 54.25-}4.68 and patients with MVO had mean 47-}5.41 with p-value=0.029 while no significant relation between score index, left ventricle end systolic diameter ( LVESD), and left ventricle end diastolic diameter (LVEDD) with MVO with p-value >0.05. As regard-ing occurrence of MVO and ECHO there were significant difference in score index between patients with MVO and patients without MVO (p-value<0.05) Also, EF has significant difference between patients with MVO and patients without MVO (p-value <0.05).
After revascularization score index by ECHO has signif-icant relation in prediction of MVO (p-value=0.019). Also, score index by CMR has highly significant relation in predic-tion of MVO (p-value <0.001).
Conclusion: We conclude that data obtained by CMR are better than ECHO in assessment of MVO and MACE. Delay in revascularization by PCI after STEMI affect cardiac muscle and was associated with post revascularization chest pain, so we should start revascularization by primary PCI as soon as possible to protect cardiac muscle from infarction.