Usefulness Of The Index Of Microcirculatory Resistance For Assessing Short-term Clinical Outcome After Percutaneous Coronary Intervention For Sub-acute Myocardial Infarction

Objectives:The objective of this study is to evaluate the clinical value of the index of microcirculatory resistance (IMR) for assessing short-term clinical outcome of patients with sub-acute myocardial infarction undergoing elective percutaneous coronary intervention (PCI).Methods:In27stable patients with sub-acute ST-segment elevation myocardial infarction, IMR was measured immediately after successful PCI. They were divided into two groups according to IMR measurements: Group1(IMR<32U, n=14) and Group2(IMR≥32U, n=13). Transthoracic echocardiography,6minutes walking test and major adverse cardiac events (MACE) were analyzed at1-month follow-up.Results:Compared with patients with higher IMR measurements, patients with normal IMR had less recurrence of chest congestion (P=0.021), longer6minutes walking distances (P=0.049) and higher ejection fraction (EF)(P=0.039) on a median follow up of42days. There was no people experiencing myocardial infarction or stent re-implantation. The re-admission rates were not significantly different between patients with normal and abnormal IMR (P>0.05). IMR correlated significantly with recurrence of chest congestion (r=0.602, P=0.001),6minutes walking distances (r=-0.539, P=0.004) and EF during the follow up (r=-0.420, P=0.029), but not significantly with re-admission rate (r=0.163, P>0.05)and pre-PCI EF(r=-0.204,P>0.05). The EF at the follow up was related to the pre-PCI EF measurements (r=0.479, P=0.012), and the difference was not statistically significant (P>0.05).Conclusions:IMR can be regarded as a predictor of the living quality of patients with sub-acute myocardial infarction undergoing elective PCI in short term.