The Effect of Chronic Consumption of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Antagonists on Blood Pressure and Inotrope Consumption After Separation from Cardiopulmonary Bypass

Chronic use of renin-angiotensin system (RAS) antagonists (angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor antagonists (ARAS)) can cause hypotension during anesthesia. In some studies hemodynamic instability, including hypotension and its effects on the clinical outcome in patients treated with these drugs during coronary artery bypass graft (CABG) and need to excessive vasoactive drugs in these patient population, has been described. The aim of this study was to evaluate the effect of chronic consumption of ACEIs and ARAS on blood pressure and inotrope consumption during coronary artery bypass graft under cardiopulmonary bypass.
A total of 200 patients undergoing coronary artery bypass graft surgery, who were treated with either ARAS or ACEIs (n = 100) over at least 2 months, or who were not treated with any RAS antagonists (control group, n = 100) were enrolled. The mean arterial blood pressure, central venous pressure, and need for vasoactive drugs, were measured after induction of anesthesia (T1) before cardiopulmonary bypass (T2) and after separation from (CPB), (T3).
There were no significant differences regarding the mean arterial pressure (case group: T1: 84 ± 7 mmHg, T2: 77 ± 6 mmHg, T3: 83 ± 8 mmHg), (control group: T1: 85 ± 7 mmHg, T2: 81 ± 7 mmHg, T3:84 ± 6 mmHg) between two groups (P > 0.05). Also there were no significant differences regarding mean central venous pressure, mean heart rate, and vasoactive drug consumption between the two groups during the time of intervals.
We found that preoperative (RAS) antagonist’s continuation have not profound hemodynamic changes during coronary artery bypass graft under cardiopulmonary bypass and so we conclude that omitting these drugs before surgery did not have a sufficient advantage to be recommended routinely.