Plaque Image Characteristics, Hyperhomocysteinemia, and Gene Polymorphism of Homocysteine Metabolism-Related Enzyme (MTHFR C677T) in Acute Coronary Syndrome

This study aims to investigate the correlation between the different characteristics of plaques, plasma level of homocysteine (Hcy), and gene polymorphism of Hcy metabolism-related enzyme. In this consecutive case–control study, we measured the plasma Hcy level using fluorescence biochemistry method and examined the gene polymorphism of Hcy metabolism-related enzyme methylenetetrahydrofolate reductase (MTHFR) C677T using TaqMan probe technology. We also examined these using intravascular ultrasound. We studied the characteristics of the plaque, measured the cross-sectional areas of the external elastic membrane and the lumen, calculated the plaque area, plaque burden, and eccentricity index, and examined the remodeling index. Hard plaques were more dominant in the (SPA) group, whereas soft plaques were more dominant in the acute coronary syndrome (ACS) group (P < 0.001). The risk of plaque rupture and thrombus is higher in the ACS group (P < 0.05). Compared with SPA group, plaque burden was heavier in the ACS group (P < 0.05), but the eccentricity index is significantly higher in SPA group than in the ACS group (P < 0.001). Positive remodeling was more frequent in ACS group, whereas negative remodeling was more frequent in the SPA group (P < 0.001). Plasma Hcy levels were higher in the unstable than in the stable plaque group (P < 0.001). The constituent ratio of MTHFR C677T genotype were different in stable plaque group and vulnerable plaque group (P < 0.05). The T genotype can increase the incidence rate of vulnerable plaque. Hcy and MTHFR C677T gene polymorphism were found to be risk factors for vulnerable plaque. Therefore, these can be used as indices to predict the instability of atherosclerotic plaque.