Clinical And Laboratory Predictors In Patients With Coronary Slow Flow Phenomenon

BackgroundCoronary slow flow phenomenon(CSFP)is a coronary artery disease in which coronary angiography shows no obvious stenosis,but there is a delay in blood flow perfusion.The etiopathogenesis mechanisms of CSFP are still unclear,and there is no fixed treatment for CSFP.The purpose of this study is to analyze the clinical and laboratory predictors of CSFP patients,and to provide a reference for exploring the potential mechanisms and treatments of CSFP.MethodsPatients with angiographically normal epicardial arteries were enrolled(145 patients with CSFP and 145 normal controls).Collected clinical information and laboratory indexes,which measured by peripheral venous blood samples before coronary angiography.The data were analyzed statistically.The chi-squared test or Fisher’s exact test was applied for categorical variables,and the independent-sample t-test or the Mann-Whitney U test was used for continuous variables.Multivariate logistic regression analyses were used to identify independent predictors of CSFP.All variables found to be significant in the univariate analysis were included in the logistic regression model.Among the variables with a significant difference on univariate analysis,those with multicollinearity were not included in this regression model.The Spearman correlation coefficient was used to identify associations between two variables.The study population was divided into tertiles based on the preprocedural monocyte count(T1:<0.31*10~9/L,T2:0.31-0.41*10~9/L,and T3:>0.41*10~9/L).Comparisons of multiple mean values were carried out by Kruskal-Wallis test.Receiver operating characteristic(ROC)curve analysis was performed to explore the sensitivity and specificity of factors in predicting CSFP,as well as the corresponding optimal critical value.ResultsUnivariate analysis showed that compared with the normal control group,CSFP patients had a higher proportion of men,higher body mass index,and lower heart rate.Blood tests showed that the number of red blood cells in patients with CSFP increased,but the volume of red blood cells decreased;the number of monocytes increased significantly,and the platelet-to-lymphocyte ratio decreased.In renal function tests,serum creatinine and uric acid levels were significantly increased in patients with CSFP.In liver function tests,the levels of globulin,bilirubin,and alanine aminotransferase were increased in patients with CSFP.Moreover,the level of high-sensitivity C-reactive protein in CSFP patients was higher than that in the normal control group.On multivariate regression analysis,the monocyte count,serum creatinine,globulin and platelet-to-lymphocyte ratio levels were independent predictors of CSFP.The monocyte count,serum creatinine and globulin levels showed a positive correlation with the TIMI frame count in coronary arteries.ROC curve analysis revealed a cut-off of 0.405*10~9/L for the monocyte count,with 48.5%sensitivity and74.5%specificity(P=0.001,area under the ROC curve(AUC)=0.613);64.5μmol/L for serum creatinine,with 65.4%sensitivity and 56.6%specificity(P<0.001,AUC=0.636);and 25.5g/L for globulin,with 40.8%sensitivity and 74.5%specificity(P=0.003,AUC=0.603).ConclusionsThe monocyte count,serum creatinine and globulin levels were found to be independent predictors of CSFP.The monocyte count,serum creatinine and globulin levels were significantly higher in the CSFP patients than the controls,with a positive association between these parameters and the extent of CSFP.These changes may lead to CSFP via inflammation,atherosclerosis and endothelial dysfunction.