Cardiology Journal 2016, Vol. 23, No. 1, 107–113 DOI: 10.5603/CJ.a2015.0064 Copyright © 2016 Via Medica ORIGINAL ARTICLE ISSN 1897–5593 A new risk scoring model for prediction of poor coronary collateral circulation in acute non-ST-elevation myocardial infarction Mehmet İleri1, Ümit Güray1, Ertan Yetkin2, Havva Tuğba Gürsoy1, Pınar Türker Bayır1, Deniz Şahin1, Özgül Uçar Elalmış1, Yahya Büyükaşık3 1Department of Cardiology, Ankara Numune Education and Research Hospital, Ankara, Turkey 2Department of Cardiology, Ortadoğu Hospital, Mersin, Turkey 3Department of Hematology, Faculty of Medicine, Hacettepe University, Ankara, Turkey Abstract Background: We aimed to investigate the clinical features associated with development of coronary collateral circulation (CCC) in patients with acute non-ST-elevation myocardial infarction (NSTEMI) and to develop a scoring model for predicting poor collateralization at hospital admission. Methods: The study enrolled 224 consecutive patients with NSTEMI admitted to our coronary care unit. Patients were divided into poor (grade 0 and 1) and good (grade 2 and 3) CCC groups. Results: In logistic regression analysis, presence of diabetes mellitus, total white blood cell (WBC) and neutrophil counts and neutrophil to lymphocyte ratio (NLR) were found as inde- pendent positive predictors of poor CCC, whereas older age (≥ 70 years) emerged as a negative indicator. The final scoring model was based on 5 variables which were significant at p < 0.05 level following multivariate analysis. Presence of diabetes mellitus, and elevated total WBC (≥ 7.85 × 103/µL) and neutrophil counts (≥ 6.25 × 103/µL) were assigned with 2 points; high NLR (≥ 4.5) with 1 point and older age (≥ 70 years old) with –1 point. Among 30 patients with risk score £ 1, 29 had good CCC (with a 97% negative predictive value). On the other hand, 139 patients had risk score ≥ 4; out of whom, 130 (with a 93.5% positive predictive value) had poor collateralization. Sensitivity and specificity of the model in predicting poor col- lateralization in patients with scores £ 1 and ≥ 4 were 99.2% (130/131) and +76.3 (29/38), respectively. Conclusions: This study represents the first prediction model for degree of coronary collater- alization in patients with acute NSTEMI. (Cardiol J 2016; 23, 1: 107–113) Key words: coronary collateral circulation, non-ST-elevation myocardial infarction, risk scoring Introduction study, we aimed to investigate the clinical features associated with development of CCC in patients The apparent prognostic implications of with acute non-ST-elevation myocardial infarc- coronary collateral circulation (CCC) makes it tion (NSTEMI) and to develop a scoring model necessary to have a better understanding of the for predicting poor collateralization at hospital factors promoting collateral development. In this admission. Address for correspondence: Mehmet Ileri, MD, Department of Cardiology, Ankara Numune Education and Research Hospital, Samur Sokak, 30/10, Kurtuluş, Ankara, Turkey, tel: ++90 505 485 9803, e-mail: [email protected] Received: 13.07.2015 Accepted: 05.09.2015 www.cardiologyjournal.org 107 Cardiology Journal 2016, Vol. 23, No. 1 Methods Blood samples at hospital admission were drawn in the emergency room from the antecubital We prospectively enrolled 224 consecutive vein by careful venipuncture using a 21-gauge patients with NSTEMI admitted to our coronary needle attached to a sterile syringe without sta- care unit within 24 h of symptom onset and sched- sis. Hematological parameters such as red blood uled to undergo coronary angiography within cells, platelets, white blood cells (WBC) and 48 h of hospitalization. Patients who did not have their subtypes were measured in blood collected a significant stenosis ≥( 70%) in at least one of in dipotassium ethylenediaminetetraacetic acid the major epicardial coronary arteries in coronary (EDTA) containing tubes by flow cytometry in an angiograms were excluded from the study. Left automated blood cell counter (Sysmex, XT-2000i) main coronary artery narrowing of ≥ 50% was also immediately within 30 min after sampling. Neu- considered significant. NSTEMI was diagnosed in trophil to lymphocyte ratio (NLR) was calculated the presence of two following criteria: (1) an ac- as the mean value of the ratio of neutrophils to celerating pattern of prolonged (lasting > 20 min) lymphocytes, both obtained from the same blood angina or recurrent episodes of angina either at sample. rest or during minimal exertion within the 48 h; The study was approved by the local bioethi- and (2) levels of cardiac biomarkers (troponin or cal committee and all patients gave their informed creatine kinase MB isoenzymes) above the upper consent. limit of the normal range. The exclusion criteria were overt congestive heart failure, idiopathic Statistical analysis dilated or hypertrophic cardiomyopathy, chronic Statistical Package for Social Sciences (SPSS) active pulmonary disease, history of renal or he- version 17.0 (SPSS Inc., Chicago, Illinois, USA) patic dysfunction, inflammatory rheumatic disease, was used for all statistical calculations. A 2-tailed recent infection, cancer, and pregnancy. p value lower than 0.05 was considered to be sta- According to our early invasive strategy, tistically significant. The categorical variables were quantitative coronary angiography was performed shown as numbers of cases with percentages. Con- in all patients within 48 h after admission in mul- tinuous variables were defined as mean ± standard tiple orthogonal projections using the Judkins deviation for parametric; and median with minimum technique by 2 experienced independent inter- and maximum levels for nonparametric variables. ventional cardiologists. Decisions regarding the Student’s t-test was used for analysis of continuous revascularization method were left to the discre- variables that were normally distributed. The c2 test tion of the interventionalists. When percutaneous (or Fisher’s Exact test if required by sample size) coronary intervention was believed appropriate was used to compare categorical data. The possible on the basis of coronary anatomy, culprit vessel factors identified with univariate testing were fur- stenting was performed in the same setting. In ther entered into multiple logistic regression analy- the case of multivessel interventions, non-culprit sis to determine the independent predictors of poor vessels could be revascularized in the same setting collateralization. A scoring system for prediction of or in a staged procedure. Coronary collateral grad- poor collateralization was developed depending on ing was carried out by 2 experienced cardiologists the results of logistic regression analysis as just who are not informed of the clinical characteristics previously described [2]. Briefly, the lowest regres- and biochemical results of the study patients. sion coefficient (B value) of significant parameters Collateral development was graded according to in multivariate analysis was scored with 1 point. the Cohen-Rentrop method [1]: grade 0 (no filling Regression coefficients of other significant param- of any collateral vessels); grade 1 (filling of side eters were divided by the lowest one and the results branches of the artery to be perfused by collat- were rounded to the nearest integer. Consequently, eral vessels without visualization of the epicardial every significant parameter in logistic regression segment); grade 2 (partial filling of the epicardial analysis was scored with a point correlated with its segment by collateral vessels); grade 3 (complete impact. These individual points were then added filling of the epicardial artery by collateral ves- together to provide a total risk score for every sels). Patients were then divided into two groups patient. Receiver operating characteristic (ROC) according to their collateral grades; with the first curve analysis was performed as needed in order group having poorly developed CCC (grade 0 and 1) to determine the best cut-off values for numerical and the second group having well-developed CCC values including the developed score in prediction (grade 2 and 3). of poor collateralization. 108 www.cardiologyjournal.org Mehmet İleri et al., A new model for prediction of poor coronary collateral circulation Results (≥ 70 years) emerged as a negative indicator. The final model was based on 5 variables which were Univariate analysis significant at the p < 0.05 level following multivari- Baseline clinical characteristics and labora- able logistic regression analysis. The score includes tory findings including hematological parameters these variables namely; age, diabetes mellitus, in study population at hospital admission were WBC count, neutrophil count and NLR. Optimal summarized in Table 1. Data also included the cut-off values for WBC count, neutrophil count, and comparison of these parameters in poor and good NLR as determined by ROC analysis were 7.85 × CCC groups. A total of 224 patients (146 male × 103/µL, 6.25 × 103/ µL and 4.5, respectively. and 78 female, mean age 65 ± 9 years old) were These three parameters were still significantly enrolled in this study. Rentrop coronary grade was associated with CCC when they were categorized distributed as followed among patients: 92 (41.1%) by their cut-off levels. with grade 0, 53 (23.7%) with grade 1, 47 (21.0%) with grade 2 and 32 (14.3%) with grade 3. There Model for prediction of poor CCC were 145 patients in poor CCC group and 79 pa- As shown in Table 3, presence of diabetes