The preservation effect of coronary collateral circulation on left ventricular function in chronic total occlusion and its association with the expression of vascular endothelial growth factor A

Abstract

Background. Patients with coronary chronic total occlusion (CTO) typically have collateralization of the distal vessel, and these collaterals can contribute to the relief of ischemia and anginal symptoms and to the preservation of ventricular function. Objectives. To investigate the preservation effect of coronary collateral circulation on left ventricular (LV) function in coronary CTO, and to explore the potential mechanism behind the development of coronary collateral circulation. Material and methods. A total of 102 consecutive patients with coronary CTO were divided into 2 groups: the left ventricular ejection fraction (LVEF)-preserved group (LVEF ≥ 50%; n = 46) and the LVEF-decreased group (LVEF < 50%; n = 56). Clinical, angiographic and laboratory data was collected for all patients. The association between LVEF and coronary collateral circulation in coronary CTO patients was analyzed with multivariate logistic regression analysis, and the serum levels of VEGF-A and the mRNA expression levels of the VEGF-A gene were compared between different grades of coronary collateral circulation. Results. Multivariate analysis revealed that Rentrop grades 2-3 and coexisting collateral pathways were independent predictors of LVEF preservation in coronary CTO patients. Patients with Rentrop grades 2-3 had smaller left ventricular end diastolic diameters (LVDd) and left ventricular end systolic diameters (LVSd), and they had larger LVEFs than the patients with Rentrop grades 0-1. Patients with Rentrop grades 2-3 also had higher serum levels of VEGF-A and higher mRNA expression levels of the VEGF-A gene in their peripheral blood mononuclear cells (PBMCs) than patients with Rentrop grades 0-1. Patients with coexisting collateral pathways had higher serum levels of VEGF-A and higher mRNA expression levels of the VEGF-A gene in PBMCs than patients without coexisting collateral pathways. Conclusions. Coronary collateral circulation is significantly associated with LVEF preservation, and VEGF-A might promote the formation of coronary collateral circulation.