Objective: The objective of this study was to evaluate the influence of cardiopulmonary bypass (CPB) on endothelin-1 (ET-1) expression in various circulation compartments in patients undergoing myocardial revascularization.
Methods: A total of 30 patients were randomized to undergo myocardial revascularization with (CABG, n = 15) or without (OPCAB, n = 15) CPB. Samples were taken preoperatively, after establishing CPB and after CPB (CABG group), prior to and after revascularization (OPCAB group), and 6 and 24 h postoperatively. Values of ET-1 were compared between groups at all time points and correlated with postoperative cardioselective enzyme values and clinical parameters.
Results: In OPCAB group, ET-1 levels did not significantly vary between time points. In CABG group, ET-1 levels were significantly elevated vs. baseline in arterial: ART-T2 vs. ART-T0 (1.83 ± 1.81 vs. 0.76 ± 1.07 fmol/mL, p = 0.05), pulmonary: SG-T2 vs. SG-T0 (2.70 ± 2.75 vs. 0.39 ± 0.28 fmol/mL, p < 0.001) and SG-T3 vs. SG-T0 (1.56 ± 0.28 vs. 0.39 ± 0.28 fmol/mL, p < 0.001), and coronary circulation CS-T2 vs. CS-T1 (1.12 ± 0.49 vs. 0.27 ± 0.09 fmol/mL, p = 0.01). ET-1 levels were significantly higher in CABG group in all vascular compartments: ART-T2 (1.83 ± 1.81 vs. 0.17 ± 0.16 fmol/mL, p = 0.02), ART-T4 (0.99 ± 0.56 vs. 0.24 ± 0.12 fmol/mL, p = 0.01), SG-T1 (0.59 ± 0.15 vs. 0.25 ± 0.13 fmol/mL, p = 0.01), SG-T2 (2.70 ± 2.75 vs. 0.30 ± 0.24 fmol/mL, p = 0.004), SG-T3 (1.56 ± 0.28 vs. 0.35 ± 0.31 fmol/mL, p < 0.001), SG-T4 (1.34 ± 0.11 vs. 0.34 ± 0.16 fmol/mL, p < 0.001), and CS-T2 (1.12 ± 0.49 vs. 0.12 ± 0.12 fmol/mL, p = 0.004). Coronary sinus ET-1 level after CPB (CS-T2) in CABG group correlated positively with troponin-I level 24 h postoperatively (r(2) = 0.802, p = 0.02) CONCLUSION: Off-pump myocardial revascularization attenuates ET-1 expression in all investigated vascular compartments. Elevated coronary ET-1 levels after CPB in CABG group correlate with troponin-I levels 24 h postoperatively.