Effects of the Discontinuation of Angiotensin-Converting Enzyme Inhibitors 12 and 24 Hours Before Open-Heart Surgery on Hemodynamics During and After Surgery

Background: Preoperative use of angiotensin-converting enzyme inhibitors (ACEIs) is an independent predictor of the need for inotropic support postoperatively and hypotension during surgery; consequently, some surgeons suggest that ACEIs be discontinued prior to coronary artery bypass graft surgery (CABG). However, the optimal time of ACEI discontinuation before CABG remains controversial. In this study, we compared the effects of ACEI discontinuation 12 and 24 hours before open-heart surgery on the hemodynamic status of patients during surgery. Methods: This randomized controlled trial was conducted on patients undergoing elective CABG. The patients were randomly divided into 2 groups: in the first group, ACEIs were discontinued 12 hours before CABG and in the second group, ACEIs were discontinued 24 hours before CABG. Hemodynamic evaluations including blood pressure (systolic, diastolic, and mean arterial pressures), the heart rate, and the hemoglobin level were performed. Results: The trends of changes in systolic blood pressure (P = 0.41), diastolic blood pressure (P = 0.360), the heart rate (P = 0.11), and the hemoglobin level (P = 0.92) were not significantly different between the 2 groups over time. The mean arterial pressure was significantly different between the groups over time (P = 0.038). Likewise, the mean arterial pressure in the 24-hour group was significantly higher than that of the other group until the time of sternotomy, after which time the mean arterial pressure in the 12-hour group was significantly higher. Conclusions: ACEI discontinuation before CABG had some effects on the hemodynamics of our patients during anesthetic induction, including the prevention of hypotension during surgery; nonetheless, our data did not show the optimal time to stop ACEIs prior to CABG.