Predictive Value Of Endothelial Function In Diagnosis And Percutaneous Coronary Intervention For Coronary Artery Disease

Part 1 Objective:To assess the predictive value of flow-mediated vasodilation (FMD) in the brachial artery (BA), endothelium-dependent vasodilatation in the carotid artery for coronary artery disease (CAD) and to evaluate the diagnostic accuracy in patients with CAD. Methods:A total of 158 consecutive patients with clinically suspected CAD underwent FMD by using high-resolution ultrasound 1th day before coronary angiography(CA). Coronary stenosis index (CSI) was calculated from coronary angiography. Results:106 patients were diagnosed CAD, and 52 patients showed no CAD (NL). FMD was significantly lower in patients with CAD compared with NL patients (FMD,4.68±2.06% vs.8.13±2.55%). In patients with 3-vessel disease of CAD, FMD was lower than in those with more localized coronary involvement (2.01±2.0% vs 5.76±1.08%, p<0.05). There was also a significant correlation between FMD and CSI (r=-0.61, P<0.0001). Multiple logistic analysis revealed that FMD (OR:1.522,95%CI:1.094-2.117, p=0.0126)are independent predictor for CAD. Analyzing the receiver operating characteristic curves we found that FMD values≤5.8% had sensitivity 82%, specificity 85%, PPV92%, and NPV 68% for the presence of significant CAD. Conclusions:In CAD patients, FMD could represent a surrogate diagnostic method for assessment of CAD.Part 2 Objective: The relationship between endothelial damage/dysfunction and CAD is well recognized. The effects of percutaneous coronary intervention (PCI) [stenting/angioplasty] on circulating markers of endothelial damage/dysfunction (von Willebrand factor [vWF], soluble E-selectin [E-sel] levels) has been less well defined in patients with stable CAD. Methods:We investigated the effects of both diagnostic CA [n=15; blood sampling immediately before CA and 15 min after CA] and PCI (n= 39; blood sampling before PCI, local of PCI,15 min after PCI) on levels of vWF and E-sel across comparable patient groups.Results:There were no differences in baseline levels of vWF, or E-sel between the two study groups (CA, PCI; all p= not significant). Following CA (before to 15 min after), there were no significant changes in vWF and E-sel (p=not significant). Following PCI, there were increases observed at baseling of PCI, loc of PCI and at 15 min after PCI in vWF (p=0.407), and E-sel (p=0.024), but only E-sel at 15 min after PCI were higher than those of baseline(p= 0.001). In CA, a positive relation between changes of vWF and E-sel(r=0.53,p=0.024), and there is also find that a positive relation between changes of vWF and E-sel when compareing loc of PCI and after PCI (r=0.41,p=0.009). Conclusions:We observed increases in two endothelial markers (vWF, and E-sel) with elective PCI but not CA. This is possiblely in keeping with endothelial damage/dysfunction following PCI. Part 3 Objective:Recent researches showed FMD was an indicator for risk stratification. While it was not clear of the long-term association between FMD and subsequent cardiovascular events(CVE) in patients with stable CAD following PCI, thus the goal of the current study was to investigate the prognostic value of FMD in stable CAD patients. Methods:A total of 82 stable consecutive patients with CAD received successful PCI were included in this study. FMD in Subjects were determined by using ultrasound before PCI. The extent of coronary artery lesions was measured by quantitative coronary artery angiography (QCA). Subjects were tracked for subsequent CVE:cardiac death, myocardial infarction, unstable angina/non-ST elevation myocardial infarction, heart failure, PCI, coronary artery bypass and stroke. Results:12 patients had an event during 12.1±1.1 months follow-up including cardiac death (1 patients), MI (2 patients), unstable angina/non-ST elevation (2 patients), heart failure (2 patients) and stroke (1 patients), patients recieved coronary bypass grafts(1 patient) and percutaneus coronary interventions(3 patients) respectively. FMD was significantly lower in patients who had an event compared with those without an event (6.65±2.67% vs.4.28±1.71%, P=0.041). By multivariate Cox regression analysis including all the variables evaluated at baseline, a diagnosis of diabetes mellitus (Odds Ratio:8.238,95% confidence interval:1.036-6.503, p=0.0462) and FMD (OR 0.614,95% CI 0.381 to 0.989, p=0.0451) were independent predictors in this model. Receiver operating characteristic (ROC) curve analysis revealed FMD (ROC area:0.667,95% confidence interval:0.642-0.974, p= 0.0273, optimal threshold:≤4.8%) had a predictive value with sensitivity of 75%, specificity of 66%separately for CVE. Conclusions:In patients with stable CAD, early evaluation of endothelial function after PCI may assist in providing as prognostic markers to stratify patients according to future risk of CVE.