| Background:Coronary atherosclerotic heart disease (CHD) is considered as myocardial ischemia, hypoxia or necrosis caused by coronary stenosis or occlusion in patients with coronary artery atherosclerotic lesions. CHD is common, which more often affected males than females. According to epidemiological survey, half of healthy 40-year-old males will develop CAD in the future while one in three healthy 40-year-old women. It may affect individuals at any age but becomes dramatically more common at progressively older ages. Furthermore, more and more young ages may be affected. CHD which is a threat to health is the leading cause of death for both men and women.Coronary angiography is a procedure that uses the contrast material and x-rays to show how blood flows through the coronary arteries in your heart. It is the best device to diagnosis the CAD in clinical practice. The decision to perform a percutaneous coronary intervention (PCI) is usually based on angiographic results alone. With the development of coronary angiography application and more deeply understanding physiological and pathological behavior of human’s cardiovascular system, researchers discover that coronary angiography is limit to gauge the functional significance of a coronary stenosis, especially for patients with moderate coronary stenosis. As is known to all, myocardial ischemia is an independent predictor of adverse cardiovascular events. Patients with coronary stenosis which may cause myocardial ischemia are prone to myocardial infarction and death, which is 12 times more than no-inducing-ischemia coronary stenosis. In ischemic heart disease, deciding which narrowing is the culprit lesion is not always clear-cut. Revascularization of stenotic coronary lesions that induce ischemia can improve a patient’s functional status and outcome. For stenotic lesions that do not induce ischemia, however, the benefit of revascularization is less clear, and medical therapy alone is likely to be equally effective.Fractional flow reserve (FFR) is a technique used in coronary catheterization to measure pressure differences across a coronary artery stenosis to determine the likelihood that the stenosis impedes oxygen delivery to the heart muscle. It expresses the maximal flow down a vessel in the presence of a stenosis compared to the maximal flow in the hypothetical absence of the stenosis. FFR is calculated as the mean distal coronary pressure divided by the mean aortic pressure during maximal hyperemia. It provides a functional evaluation, by measuring the pressure decline caused by a vessel narrowing. FFR is a relatively stable indicator, which are less affected by the change in hemodynamics. The studies indicated that FFR less than 0.75 is associated with myocardial ischemia.FFR has made great achievements in optimizing percutaneous coronary intervention and it has become an accepted index to assess the functional significance of a coronary stenosis. However some patients still suffered major adverse cardiac events (MACE) after drug-eluting stent implantation.Objective:The aim of this study is to investigate the role of fractional flow reserve in predicting long-term prognosis at 1 year after drug-eluting stent implantation. Methods:291 patients including stable CAD and unstable CAD with intermediate coronary lesions were selected from January 2012 to July 2013. The patients were not eligible for enrollment if they had undergone intervention in the setting of primary or emergent PCI for acute coronary syndrome, had undergone previous coronary artery bypass graft surgery, cardiogenic shock, left main disease, extremely tortuous or calcified coronary arteries, primary myocardial disease, myocardial hypertrophy, contraindications to adenosine, aspirin, or clopidogrel and serious damage in liver and kidney function. Demographic and clinical characteristics of enrolled participants were collected by one researcher with the use of electronic case report form and then rechecked by another researcher.All patients received coronary angiography and FFR measure before and after the drug eluting stents. FFR was measured with a coronary pressure guidewire (Radi-Medical Systems) at maximal hyperemia induced by intravenous adenosine, which was administered at a rate of 140μg per kilogram of body weight per minute through peripheral vein. FFR is calculated as the mean distal coronary pressure (measured with the pressure wire) divided by the mean aortic pressure (measured simultaneously with the guiding catheter) during maximal hyperemia.DES was placed in indicated lesions only if the FFR was 0.8 or less. Demographic and clinical data, the rates of MACE were compared between patients with preoperative FFR more than 0.8 and 0.8 or less. FFR was measured in 135 patients after drug-eluting stent Implantation. They were divided into two groups based on whether suffered MACE, including death from any cause, acute myocardial infarction (AMI), or repeat target vessel revascularization by bypass surgery or PCI in the 1 year follow-up. Post-stent FFR and other clinical data were compared between groups. Multivariate logistic regression was used to determine risk factors of MACE and the ROC curve of post-stent FFR was showed to identify the predictive value for MACE. Moreover, multivariate logistic regression also used to discover risk factors of lower post-stent FFR.Results:28 MACE occurred during follow up. There was no significantly difference in the rates of MACE between patients with preoperative FFR more than 0.8 and 0.8 or less. Post-stent FFR was significantly higher in patients without than in patients with MACE. Multivariate analysis showed that post-stent FFR (OR=0.212, P=0.039) was an independent predictor of MACE. Kaplan-Meier survival curves showed that patients with post-stent FF<0.875 had worst prognosis. Multivariate analysis revealed that left coronary artery involved, the higher preoperative FFR and stent diameter were associated with lower post-stent FFR.Conclusion:Post-stent FFR is a predictor of MACE at 1 year after drug-eluting stent implantation and might have predictive value for MACE. Left coronary artery involved, the higher preoperative FFR and stent diameter were associated with higher post-stent FFR. |
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