Risk Factors And Prognosis Of Intramyocardial Hemorrhage After Acute Myocardial Infarction

Background: Previous studies have shown that the incidence of major adverse cardiovascular events(MACE)in patients with acute myocardial infarction(AMI)complicated with intramyocardial hemorrhage(IMH)is high,but the incidence of IMH in patients with different types of AMI is not clear.Objective: To explore the incidence of intramyocardial hemorrhage in different types of AMI,and analyze the risk factors of IMH and its impact on prognosis.Methods: This study prospectively enrolled consecutive AMI patients admitted to the Cardiovascular Intensive Care Unit of the Department of Cardiovascular Medicine of Second Xiangya Hospital from April 2020 to November 2021.Cardiac MRI was performed in all patients during hospitalization to detect the presence of IMH.Collection of clinical data on patients and follow-up of all patients.Results: A total of 106 eligible patients with AMI were included in this study,including 41 patients with NSTEMI and 65 patients with STEMI.In STEMI patients,27(41.5%)patients developed IMH,while 3(7.3%)patients in NSTEMI patients developed IMH,and the incidence of IMH in STEMI patients was significantly higher than that in NSTEMI patients(41.5% vs 7.3%,P< 0.001).LVEF(AOR: 0.906,95%CI:0.844-0.973,P=0.007),microvascular obstruction(AOR: 7.722,95%CI:1.756-33.959,P=0.007)and myocardial infarction volume(AOR: 1.069,95%CI): 1.002-1.140,p=0.044)was independently associated with the occurrence of IMH in STEMI patients.Among STEMI patients,the volume of myocardial infarction in the IMH group was significantly higher than that in the Non-IMH group(34.2±12.7cm3 VS 21.1±13.1cm3,P<0.001),while the LVEF(CMR)was significantly lower than that in the Non-IMH group(30.7±13.1cm3)9.8% vs 42.3±11.0%,P<0.001).The incidence of MACE events at 12 months in the IMH group was significantly higher than that in the Non-IMH group(6/27 VS 2/38,P=0.036).Conclusions: The incidence of IMH in STEMI patients was significantly higher than that in NSTEMI patients.Decreased left ventricular ejection fraction,myocardial microvascular obstruction,and large myocardial infarct volume were independently associated with IMH in STEMI patients.IMH can further expand the volume of myocardial infarction,which in turn leads to deterioration of cardiac function and a significant increase in the incidence of MACE events.