ABC | Volume 110, Nº4, April 2018

Original Article Wang et al Monocyte count and thrombus burden Arq Bras Cardiol. 2018; 110(4):333-338 Table 1 – Baseline clinical and laboratory characteristics of the study population divided according to thrombus burden Low thrombus burden (n = 178) High thrombus burden (n = 95) p value Age (years) 62.3 ± 13.2 62.0 ± 14.7 0.866* Male sex, n (%) 143 (80.3) 77 (81.1) 0.482† Diabetes mellitus, n (%) 56 (31.5) 31 (32.6) 0.716† Hypertension, n (%) 106 (59.6) 57 (60.0) 0.503† Hyperlipidemia, n (%) 109 (61.2) 65 (68.4) 0.395† Active smokers, n (%) 75 (42.1) 47 (49.5) 0.200† Prior MI, n (%) 6 (3.4) 3 (3.2) 0.145† LVEF (%) 53.4 ± 9.7 52.9 ± 8.5 0.699* Creatinine, μmol/L 76.9 ± 24.5 81.4 ± 25.6 0.167* Peak cTnI (ng/mL) 29.8 (1.2–86.6) 56.7 (16.4–100.6) 0.037‡ *: Independent samples t-test; †: Chi-square test; ‡: Mann-Whitney U test; MI: myocardial infarction; LVEF: left ventricular ejection fraction; cTnI: cardiac troponin I. Table 2 – Baseline angiographic and procedural characteristics according to thrombus burden Variable Low thrombus burden (n = 178) High thrombus burden (n = 95) p value Time from symptom onset to PPCI 0.773 † < 3 h (%) 48 (26.9) 27 (28.4) 3–6 h (%) 66 (37.1) 38 (40.0) 6–12 h (%) 64 (36.0) 30 (31.6) Anterior infarct location, n (%) 95 (53.4) 48 (50.5) 0.918 † Infarct-related coronary artery, n (%) 0.788 † Left main 0 (0.0) 0 (0.0) Left anterior descending 95 (53.4) 49 (51.6) Left circumflex 22 (12.4) 12 (12.6) Right coronary artery 61 (34.2) 34 (35.8) Number of used stent, n 1.6 ± 0.7 1.4 ± 0.7 0.106* Total stent length, (mm) 36.7 ± 19.1 36.6 ± 17.6 0.164* Stent diameter, (mm) 3.1 ± 0.4 3.2 ± 0.5 0.164* Use of thrombus aspiration, n (%) 18(10.1) 59 (62.1) 0.000 † Tirofiban use, n (%) 93 (52.2) 79 (83.2) 0.000 † *: Independent samples t-test; †: Chi-square test. The comparison of admission hematological parameters is presented in Table 3. WBC counts, neutrophil counts, platelet count, hemoglobin, hematocrit, mean platelet volume, and lymphocyte count were similar in both groups. The patients in the high-thrombus burden group had significantly higher monocyte count when compared with the patients of low-thrombus burden group (0.61 ± 0.29×109/L vs. 0.53 ± 0.24×109/L, p = 0.021. Univariate and multivariate logistic regression analysis of the association between the angiographic high thrombus burden and multiple parameters are presented in Table 4. In multivariate analyses, on admission monocyte count was an independent predictor of angiographic high thrombus burden (odds ratio 3.107, 95% confidence interval [CI] 1.199–7.052, p = 0.020). The most discriminative cut‑off values of monocyte count were 0.48×10 9 /L, with a sensitivity of 71.9% and a specificity of 46.9% (AUC: 0.59; 95% CI: 0.515–0.654; p = 0.035). Discussion Acute STEMI is characterized by complete thrombotic occlusion of a coronary artery. The goal of PPCI in STEMI is the rapid restoration of coronary blood flow, maximum salvage of myocardium and improving patients' outcomes after STEMI. Studies have shown that intracoronary thrombi can lead to 335