MMP9 and atrial fibrillation: The AUC values of AF IL-8, lipocalin-2, MMP-9, and S100 A8/A9 for the prediction of SPTD within 14 days after sampling were 0.717, 0.725, 0.755, and 0.714, respectively (Table 3 and Fig 3), and were not significantly different from each other (all variables: P = 0.25–0.92).