The Clinical Significance Of IL-6, IL-8 And IVUS Features Of Atherosclerotic Plaques In Patients With Coronary Heart Disease

Objective:The principal reason of acute coronary syndrome(ACS)is the rupture of atherosclerotic unstable plaquethe.The former studies have shown that inflamation is a very important factor of the atherosclerotic unstable plaques rupture and thrombosis.The purposes of our study are as follows:1)to investigate the morphological features and the vulnerability of atherosclerotic plaques through intravascular ultrasound(IVUS)in stable angina pectoris(SAP)and acute coronary syndrome(ACS)patients;2)to elucidate the relationship between the plasma IL-6, IL-8 levels and the vulnerability of coronary heart disease(CHD),the vulnerability of atherosclerotic plaques and the stenosis extent of coronary artery segment.Methods:30 CHD patients were divided into two groups;15 patients in SAP group;15 patients in ACS group.The plasma IL-6,IL-8 levels were measured in all objects,then all cases were examined by CAG and IVUS to analyze the criminal lesions.The detailed parameters involved external elastic membrane area(EEMA); luminal area(LA);plaque area(PA);area stenosis percentage;eccentric index(EI)and remodeling index(RI).Results:1)The plasma IL-6,IL-8 levels were significantly higher in ACS group compared with SAP group(p＜0.01).2)The plasma IL-6,IL-8 levels were significantly higher in unstable plaque group compared with stable plaque group(p＜0.01),while there was no difference between slight stenosis group and medium-severe stenosis group(p＞0.05).3)IVUS found that patients in SAP group mainly had stable and fibrous plaques,while patients in ACS group mainly had unstable and soft lipid plaques(p＜0.01).Calcific plaques were found in SAP group as well as in ACS group with no difference(p＞0.05).EI were higher in ACS group compared with SAP group(P＜0.05).Coronary segments in ACS group were prone to positive remodeling.Conclusion:1)The majority of SAP criminal lesions are stable plaques characterized by endocentric or eccentric but with low EI fibrous plaques.On the contrary,the majority of ACS criminal lesions are mainly unstable plaques,which are more prone to positive remodeling,more eccentric and usually with large lipid pool or thin fibrosis cap.Calcific plaques are found in SAP group as well as in ACS group with no difference.2)The plasma IL-6,IL-8 levels might reflect the unstable activity of CHD as well as the plaques,but has no relationship with the stenosis extent of coronary artery segment.