Figure 1.
CABG, coronary artery bypass graft.
Table 1.
Perioperative patient characteristics and clinical data.
Table 2.
Demographic and Perioperative Characteristics of Enrolled Patients.
Figure 2.
Plasma miR and troponin I levels from 29 patients undergoing on-pump CABG (Step I).
(A–C) Mean concentrations of circulating miRs expressed as the fold increase (2−ΔΔCt scale) relative to those at the preoperative time point. On average, miR-499, miR-133a, and miR-133b exhibited a 20- to 70-fold increase in plasma samples collected 1 h and 3 h after declamping, respectively. At 48 h after declamping, the values were back to levels comparable to those in the preoperative control. (D–F) Comparison of miRs and cTnI levels in the same plasma samples showing that miR-499, miR-133a and miR-133b peaked earlier than cTnI. (*P<0.01; $P<0.05 vs. control) (G–I) Correlations between the maximum levels of miRs and cTnI. MiR-499 (G), miR-133a (H) and miR-133b (I) correlated significantly with cTnI levels (respectively P<0.001; P<0.01 and P<0.05).
Figure 3.
Pump-on and pump-off differences in miR-499 (Figure 3A) and miR-133a (Figure 3B) concentrations.
The two curves differ significantly (p<0.0001) for both miR-499 and mIR-133a. In the arrested heart (on-pump) group versus the beating heart (off-pump) group, the miR-499 concentrations were significantly higher at post-declamping hours 1, 3, 6, 12, and 24 (p<0.0001), while the miR-133a concentrations were significantly higher at hours 1, 3, and 12 (p<0.0001). All mean±standard deviation levels are expressed as fold increase (2−ΔΔCt scale) relative to those in the preoperative control.
Figure 4.
Receiver operating characteristic(ROC) curves for the identification of PMI at 6 hours after CABG.
The thin diagonal line is the Null Hypothesis: True area = 0.50. A, B and C panels show the ROC and AUC values of cTnI, miR-133a and miR-499, respectively, as thick solid lines. The dotted lines show the 95% CI of ROC curves. The highest AUC was calculated from miR-499 (0.939, p<0.0001). (A) cTnI (>2.98 ng/ml) had a sensitivity of 64.3% and specificity of 86.5% for the identification of PMI. (B) miR-133a (ΔCt<13.6417) had a sensitivity of 89.3% and specificity of 67.4% for the identification of PMI. (C) miR-499 (ΔCt<18.7477) had a sensitivity of 85.7% and specificity of 93.3% for the identification of PMI. (D) Comparison of ROC curves of cTnI(ellipses), miR-133a(rectangles) and miR-499 (asterisks) at 6 h postoperatively. Abbreviations: AUC = area under the curve; Ct = cycle threshold; cTnI = cardiac troponin I; PMI = perioperative myocardial infarction.