The Assessment Of The Myocardial Microvascular Perfusion After Coronary Revascularization By Corrected TIMI Frame Count

Background: Percutaneas Coronary interventional (PCI )therapy is a effective treatment to acute myocardial infarction. When the blood flow of infarcted arterial reaches TIMI 3, reperfusion is regarded as success. But present studies suggest that part of patients whose flood flow of epicardial coronary arteries reach TIMI 3 haven't acquired effective perfusion at myocardium level. The perfusion at myocardium level can be evaluated by acoustic contrast intra-myocardium, doppler guide wire intra-coronary artery and coloration grading of myocardium, etc. However, these techniques aren't suitable to clinical application in large-scale because they are relatively difficult to master and costly. Corrected TIMI Frame Count(CTFC) is an index introduced to quantitatively assess coronary blood flow in recent years, the drop of ST segment in ECG can indirectly reflect the damage of microcirculation of coronary artery, but the correlation between the drop and the damage hasn't been studied systematically;it has no final conclusion on the value of evaluating risk that making use of CTFC as the evaluation index of myocardial perfusion after revascularization of blocking coronary artery.Objective: Observe the feasibility that evaluating the perfusion condition of myocardial and microcirculation by CTFC in the patients with acute myocardial infarction were cured by PCI, that is blood flow reaches TIMI3, and further analyze the relation with prognosis by making use of it as the predictable index in post-PCI.Method: Retrospective study was done on 217 patients with acute myocardial infarction admitted from Jan, 2004 to Oct, 2005, analyze the clinicdata of 76 patients meeting inclusion criterion, and determine the drop degree of ST segment, CTFC value and echocardiogram after 30 days in post-PCI, in addition, record the main cardiac adverse events. Firstly, analyze the relation between CTFC and the drop of ST segment to discuss the correlation of perfusion in myocardial microcirculation and analyze the risk factors of CTFC;then group the patients by the mode of interventional therapy and the CTFC value, discuss the value that judging the prognosis of patients with acute myocardial infarction treated by PCI according to CTFC.Results: The CTFC value of the patients in ST segment depression group is the lowest (20.74 + 8.36) , that of the patients in the no ST segment depression group is the highest (28.77 + 8.35) , and that of the patients in the part ST segment depression group is medium(25.4 + 7.79). The possible factors that influence CTFC value are further analyzed with Logistic model. It is discovered that diabetes (OR=0.39, p=0.0403), direct PCI (OR=0.28, p=0.028) ,and ST segment depression (OR=0.42, p=0.0318) are the independent factors that influence CTFC value. The CTFC values in direct PCI(25.3 + 8.9 frames) and remedied PCI (25.6 + 7.9 frames) have a increasing tendency with the time of reperfusion prolonged. The influence of reperfusion time in the patients after PCI in the direct PCI group on the CTFC value is not great (p=0.94) , that in the patients in the remedied PCI group, especially the patients treated with PCI in 6 hours after the incidence of AMI, the increase of CTFC value is significant (p=0.08) along with the time from the incidence to reperfusion prolonged. In the 30th day (30±3 days) after the incidence of AMI, the LVEF value (51.5 + 9.5) of the patients in slow CTFI group is lower than that (55.9 + 9.02) of the patients in fast CTFI group, p =0.042;the incidence (50%) of major adverse cardiac events (MACE) in the patients in the slow CTFC group is much higher than that (15%, p=0.001) of the patients in the fast CTFC group.Conclusion: CTFC value can reflect the condition of the microcirculation perfusion after myocardial infarction at relatively good extent, the independentcorrelation factors reflecting CTFC include diabetes, whether direct PCI therapy or not and the drop degree of ST segment. We find that the condition of the microcirculation perfusion in the patients with acute myocardial infarction treated by direct PCI therapy is better than the patients by remedied PCI therapy. The incidence of cardiac adverse events was high in the patients with CTFC >23 frame count after acute myocardial infarction was treated by PCI, which shows the value that judging the prognosis of patients with acute myocardial infarction treated by PCI according to CTFC is relatively high.