Background: The SYNTAX score (SXscore) is a comprehensive, angiographic tool for grading the severity and complexity of coronary artery disease (CAD). The association between the circulating endothelial progenitor cell
(EPC) number and the severity and complexity of CAD determined by SXscore is unclear. The purpose of this study is to test the hypothesis that SXscore is associated with EPC levels in CAD patients.
Methods: Flow cytometry was used to assess circulating EPC numbers by quantification of EPC markers (defined as CD34+, CD34+ KDR+, and CD34+KDR+CD133+) in the peripheral blood of patients undergoing coronary
angiography.
Results: Eighty-eight patients with CAD confirmed by elective coronary artery angiography and 27 age- and sex-matched controls with normal coronary angiogram were enrolled. The SXscore index was evaluated in all CAD patients and ranged from 4 to 43, with a median of 22.We divided the CAD patients into mild CAD (SXscore: 1-22) and severe CAD (SXscore > 22) groups. Compared to mild CAD patients and controls, patients with severe CAD had a higher incidence of hypertension, previous myocardial infarction, and more severe coronary lesions. Furthermore, severe CAD patients had significantly increased concentrations of high-sensitivity C-reactive protein and decreased circulating EPC levels vs. mild CAD patients and controls. Multivariate logistic regression analysis showed that circulating EPC levels were inversely associated with severe CAD (CD34+KDR+: odds ratio, 0.93 [0.88-0.98]; p = 0.024).
Conclusion: CAD patients with high SXscore have lower circulating EPC levels and enhanced inflammation in comparison to CAD patients with low SXscore.