A pilot study of perioperative esmolol for myocardial protection during on-pump cardiac surgery

Abstract

The protective effects of preprocedural esmolol on myocardial injury and hemodynamics have not, to date, been investigated in patients who were scheduled for cardiac surgeries under a cardiopulmonary bypass (CPB). A pilot randomized controlled trial was performed at The First Affiliated Hospital of Dalian Medical University (Dalian, China). Patients scheduled for elective open-heart surgeries under CBP were included, and were randomized to esmolol and control groups. For patients in the esmolol groups, intravenous esmolol (70 µg/kg/min) was administered at the time of incision until CPB was performed. For patients assigned to the control group, equal volumes of 0.9% saline were administered. Markers of myocardial injury and hemodynamic parameters were observed until 12 h post surgery. A total of 24 patients were included in the present study. No significant differences in hemodynamic parameters, including the central venous pressure and heart rate, were detected between patients in the two groups during the perioperative period or within the first 12 h post-surgery (P>0.05), except for the mean arterial pressure, which was higher in the esmolol group compared with the control group at 5 and 12 h post-surgery (P<0.05). However, the serum level of cardiac troponin I was higher in patients of the control group compared with those of the esmolol group during the preoperative period (P<0.05). Although creatinine kinase was significantly different at T2 between the two groups, its MB isoenzyme was not significantly different between the groups (P>0.05). In addition, administration of esmolol was not associated with an increased risk for severe complications and adverse events in these patients. In conclusion, preoperative esmolol may be an effective and safe measure of myocardial protection for patients who undergo elective cardiac surgeries under CBP.

Keywords: cardiac surgery; cardiopulmonary bypass; esmolol; ischemia-reperfusion injury; myocardial protection.

Figure 1.

Changes in the (A) MAP, (B) CVP and (C) HR during the perioperative period of the patients in the esmolol and control groups. ^#P<0.05 vs. the control group. MAP, mean atrial pressure; CVP, central venous pressure; HR, heart rate; OR, operating room.

Figure 2.

Perioperative changes in the levels of (A) TnI, (B) CK and (C) CK-MB in the esmolol and control groups. T0, at baseline; T1, before aortic cannulation; T2, 30 min before aortic cross-clamp; T3, release of aortic cross-clamp; T4, 120 min after release of aortic cross-clamp. ^#P<0.05 vs. the control group. TnI, troponin I; CK, creatine kinase; CK-MB, creatine kinase MB.

Figure 3.

Changes in the (A) MAP, (B) CVP and (C) HR during the first 12 postoperative hours in the esmolol and control groups in the Intensive Care Unit. ^#P<0.05 vs. the control group. MAP, mean atrial pressure; CVP, central venous pressure; HR, heart rate.