Outcomes of Angiotensin Converting Enzyme Inhibitor Management Strategies Prior to Coronary Artery Bypass

COMParison of Angiotensin Converting Enzyme Inhibitor managemenT Strategies Prior to Coronary Artery Bypass Surgery (the COMPACT Trial): a Pilot Randomized Controlled Registry Study

Coronary artery disease is a leading cause of death, hospitalization, and health care costs in developed nations. Coronary revascularization with coronary artery bypass graft (CABG) surgery improves the long term survival in patients with diabetes and multi-vessel disease. Angiotensin converting enzyme inhibitors (ACE) and angiotensin receptor blockers (ARB) reduce mortality and subsequent cardiac events in patients with coronary artery disease undergoing CABG surgery when initiated at least 4 weeks pre-operatively. Observational data have suggested that pre-operative ACE administration is associated with an increased risk of post-operative vasoplegic shock, acute kidney injury, and mortality; however, other studies have failed to confirm these findings and further suggested ACE are associated with a reduced risk of peri-operative myocardial infarction. A single trial of 40 CABG patients randomized to pre-operative ACE withdrawal or continuation reported that the withdrawal group required significantly fewer vasopressors during cardiopulmonary bypass but more intravenous vasodilators post-operatively to control hypertension. Hence, it remains unclear whether ACEs should be held or continued immediately prior to CABG surgery and a survey of cardiac surgeons suggests that current clinical practice is divided. This pilot study aims to establish the feasibility of the study design and to determine the frequency of clinical endpoints among patients who continue and discontinue ACE prior to cardiac surgery.

Inclusion Criteria:

• Patients undergoing elective or urgent isolated CABG and/or valvular repari or replacement surgery
• On an ACE or ARB for a minimum of 7 days

Exclusion Criteria:

• Emergency surgery
• Pre-operative shock (defined as systolic blood pressure < 90 mmHg, the need for any vasopressor or inotropic support, or a mechanical cardiac support device)
• Severe uncontrolled pre-operative hypertension (defined as blood pressure ≥ 200 mmHg systolic or ≥120mmHg diastolic mmHG or the pre-operative need for intravenous anti-hypertensive agents)
• ACE or ARB therapy < 7 days
• Any mineralocorticoid receptor antagonist therapy.