| Background: The morbidity of coronary heart disease (CHD) is rising in our country. Acute myocardial infarction (AMI) is the main reason causing patients with CHD death. AMI is classified to two types according to ST-segment of electrocardiograph (ECG): ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infartion (NSTEMI). Early, sufficient and sustained patency of the infarct-related coronary artery (IRA) has become the main goal in the care of patients with STEMI. Thrombolytic therapy and percutaneous coronary intervention (PCI) are the two principal methods for reperfusion. PCI has been widely performed because of better recanalization rate and less residual stenosis compared with thrombolytic therapy.After thrombolytic therapy or PCI in ST-segment elevation myocardial infarction, there are some patients retaining an impaired microvascular perfusion despite restoration of normal flow in the epicardial infarct-related artery, which may be owing to microcirculation damage. Several studies have clearly indicated that the main determinant of the salvage of myocardial cytes, diminution of infarction area, the recovery of LV function, amelioration of theprognosis in patients with AMI is the microvascular reperfusion of the infarcted zone. Therefore, the goal of reperfusion therapy should be not only restoration of epicardial flow but also myocardial perfusion. Now many cardiologists have focused on microvascular reperfusion of infarcted myocardium as a final goal of reperfusion therapy.Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is a valuable and widely used qualitative measure in angiographic trial, it is limited by its subjective and categorical nature. Intracoronary myocardial contrast echocardiography, positron emission tomography, radionuclide imaging and Doppler guide wire are considered the most effective techniques for assessing microvascular integrity, however, they have not found widespread application because of the demanding nature of the technique, high cost, time-consuming or not readily available in all coronary unit. On the other hand, the recovery of ST-segment elevation of ECG is a good candidate for this role. Recently, corrected TIMI frame count (CTFC) has been proposed as a simple, inexpensive, reproducible and quantitative method to assess coronary blood flow and could reflect the microcirculation reperfusion indirectly. CTFC, along with the resolution of ST-segment elevation on the 12-lead ECG, are simple tools that correlate significantly with tissue-level perfusion shortly after recanalization of the infarct-related artery (IRA). Troponin T (TnT), the tropomyosin-binding protein of the regulatory complex located on the contractile apparatus of cardiac myocytes, is a sensitive and specific marker for myocardial necrosis and it might be a surrogate marker for microembolization from liable thrombus formation. Damaged endothelium could facilitate microthrombosis and reinforce intercellular adhesion, which play an important role in microcirculation injury. The level of P-selectin (P-s) could reflect the microthrombosis formation and intercelluler adhesion.We hypothesized that after successful primary PCI (restoration of TIMIgrade 3 flow), analysis of CTFC, ST-segment elevation recovery, TnT and P-selectin might be used early to stratify patients with different levels of microvascular reperfusion and to predict the magnitude of left ventriculus functional recovery.Objective: To observe the resolution of ST-segment elevation, CTFC, TnT and P-s of patients with ST-segment elevation acute myocardial infarction after successful PCI. To discuss the reliable and convenient markers to evaluate myocardial tissue perfusion, in order to tailor the pharmacological interventions, such as additional antiplatelet therapy so as to ameliorate the perfusion of microcirculation.Methods: 23 patients with their first ST elevation acute myocardial infarction underwent successful emergency PCI with onset≤12 hours were considered for enrolment in the study. After PCI, all the patients'epicardial coronary flow had achieved TIMI 3 grade. To record the CTFC with INNOVA 2000 digital angiographic system equipped with a frame counter. A 12-lead ECG was recorded just before and 1 h after the procedure to assess the recovery of ST-segment elevation. To measure TnT with electrochemilumi-nescence (ECL) and P-s with enzyme-linked immunoadsordent assay (ELISA). To examine the ventricular wall motion score index (WMSI) and left ventricular ejection fraction (EF) with HP Sonos 2500 echocardiogram. Patients were divided to two groups according to CTFC: CTFC<23 as fast group and 23≤ CTFC<40 as slow group. To analyse the ST resolusion, TnT and P-s of the two groups.Results:1. There were no significant differences between the two groups with regard to age, sex, mean blood pressure, heart rate, incidence of coronary risk factors, body-mass index, level of cholesterol and triglyceride.2. There were no difference between the two groups with respect to many angiographic variables: location of culprit lesion, collateral circulation,reference diameter, minimal luminal diameter, maximum inflation pressure, stent diameter, stent length, residual stenosis, TIMI flow grade before reperfusion. However, elapsed time from the onset of symptoms to reperfusion in CTFC slow group was significantly longer than that of the CTFC fast group (5.8+2.6 vs. 4.5±2.1 h, P<0.05). After PCI, the frame number of the CTFC slow group was significantly higher than that of the fast group (31.7 + 5.2 vs. 19.4 + 2.6, P<0.05).3. The percentage of complete ST-segment-elevation resolution of CTFC slow group was lower than that of CTFC fast group (28.6% vs. 62.5%), while the percentage of no ST-segment-elevation resolution was higher than that of CTFC fast group (28.6% vs. 6.3%). There was no significant difference between the two groups with regard to the percentage of partial ST-segment-elevation resolution .4. The WMSI and EF significantly improved at one month in both groups, but the A WMSI and AEF in the CTFC fast group were significantly higher than that of CTFC slow group (A WMSI: 1.33 + 0.43 vs. 0.65+0.37, P<0.05; AEF: 9.6+4.1 vs. 4.3+3.5, P<0.05). CTFC had a significant correlation with the change in WMSI and EF (r=-0.7637, P<0.0001; r=~0.5691, P=0.0046).5. The cTnT level in the two groups before and lh after PCI were higher than the normal reference range. The cTnT level of CTFC slow group was higer than that of CTFC fast group.6. In patients with AMI of the two groups before and 4 after PCI, we found a significantly increased P-s level compared with the control healthy people and the level of the CTFC slow group was higer than that of the CTFC fast group.Conclusions: The results suggested:1. There were significant difference of clinical prognosis and cardiac functional restoration in patients with AMI after successful PCI.
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