Prognostic Value of Matrix Metalloproteinase 9 (MMP9) in Patients Following Off-Pump Coronary Artery Bypass Grafting

Figures

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  Figure 1. Preoperative and postoperative plasma MMP9 levels in patients. Box plots illustrate the distribution of plasma MMP9 concentrations measured preoperatively (Pre-OP) and 48 h postoperatively (Post-OP). Within each box plot, the central horizontal line indicates the median value. The box itself represents the interquartile range (IQR), extending from the first quartile (Q1, bottom edge of the box) to the third quartile (Q3, top edge of the box). The whiskers extend vertically from the box to show the minimum and maximum observed values in the dataset: Pre-OP Group: Median = 249 ng/mL; Q1 = 222 ng/mL; Q3 = 275 ng/mL; Minimum = 126 ng/mL; Maximum = 300 ng/mL. Post-OP Group: Median = 126 ng/mL; Q1 = 123 ng/mL; Q3 = 129 ng/mL; Minimum = 108 ng/mL; Maximum = 131 ng/mL. The difference between preoperative and postoperative MMP9 levels was statistically significant (assessed via paired Wilcoxon signed-rank test; ** p < 0.01).

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  Figure 2. Frequency distribution of plasma MMP9 levels at 1-year follow-up, illustrating patient stratification into two subgroups. This histogram displays the distribution of plasma MMP9 concentrations measured in patients one year postoperatively. The x-axis represents plasma MMP9 concentration (in ng/mL), and the y-axis indicates the frequency (number of patients) observed at these concentrations. Based on this distribution, patients were stratified into two subgroups for analysis: one subgroup comprising patients with MMP9 levels greater than 200 ng/mL, and the other subgroup comprising patients with MMP9 levels less than or equal to 200 ng/mL.

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  Figure 3. Correlation between plasma MMP9 levels (ng/mL) and echocardiographic parameters (LVEDV and LVEF) at 1-year follow-up. This figure illustrates the relationships between plasma MMP9 concentration and key echocardiographic parameters: Left Ventricular End-Diastolic Volume (LVEDV) and Left Ventricular Ejection Fraction (LVEF), measured one year postoperatively. Each point represents an individual patient. Solid lines indicate the linear trend. Associations were assessed using Spearman’s rank correlation coefficient (rho). (A) Correlation between 1-year plasma MMP9 concentration (y-axis, ng/mL) and 1-year Left Ventricular Ejection Fraction (LVEF, x-axis, %): Spearman’s rho = −0.762, p < 0.001. (B) Correlation between 1-year plasma MMP9 concentration (y-axis, ng/mL) and 1-year Left Ventricular End-Diastolic Volume (LVEDV, x-axis, mL): Spearman’s rho = −0.235, p = 0.008. (C) Correlation between 1-year Left Ventricular Ejection Fraction (LVEF, y-axis, %) and 1-year Left Ventricular End-Diastolic Volume (LVEDV, x-axis, mL): Spearman’s rho = 0.213, p = 0.016.