Should ACEIs Be Stopped on the Day of Surgery?
In a diabetic patient with ischemic heart disease and prior MI undergoing surgery, discontinuing ACE inhibitors 24 hours before surgery is the preferred approach to minimize intraoperative hypotension, with plans to restart them postoperatively once hemodynamically stable.
Evidence-Based Recommendation
The most recent high-quality evidence demonstrates that patients who stopped ACE inhibitors or ARBs 24 hours before noncardiac surgery had lower rates of the composite outcome (death, stroke, myocardial injury) and significantly less intraoperative hypotension compared to those continuing these medications 1, 2. This represents a shift from earlier equivocal guidance.
Guideline Consensus
For Noncardiac Surgery
The 2017 ACC/AHA Hypertension Guideline specifically recommends that discontinuation of ACE inhibitors or ARBs perioperatively may be considered (Class IIb recommendation) 1. This is based on:
- A large cohort study showing reduced composite outcomes when ACE inhibitors/ARBs were stopped 24 hours preoperatively 1, 2
- Meta-analyses demonstrating that 50% of patients experience hypotension when continuing these medications on the day of surgery, though without changes in hard cardiovascular outcomes in older studies 1
The 2014 ACC/AHA Perioperative Guideline states that continuation of ACE inhibitors perioperatively is reasonable (Class IIa), but acknowledges significant intraoperative hypotension occurs without clear benefit in preventing MI, stroke, or death 1.
For Cardiac Surgery
The 2011 ACC/AHA CABG Guideline notes that the safety of preoperative administration of ACE inhibitors in patients on chronic therapy is uncertain (Class IIb) 1. These agents are associated with:
- Severe hypotension after cardiopulmonary bypass (vasoplegia syndrome) 1
- Postoperative renal dysfunction 1
- Blunted response to pressors and inotropic agents after anesthesia induction 1
Pathophysiological Rationale
During anesthesia and surgery, ACE inhibitors block the compensatory renin-angiotensin-aldosterone system that is critical for maintaining vascular tone 2. Specifically:
- Anesthetics inhibit the sympathetic nervous system and impair baroreceptor control 2
- Preoperative fasting causes relative hypovolemia 2
- Normally, angiotensin II compensates through vasoconstriction, but ACE inhibitors prevent this mechanism 2
- This results in more profound hypotension after induction and increased vasopressor requirements 2
The FDA label for lisinopril explicitly warns: "In patients undergoing major surgery or during anesthesia with agents that produce hypotension, lisinopril may block angiotensin II formation secondary to compensatory renin release" 3.
Special Considerations for Your Patient
High-Risk Features Present
Your patient has multiple factors that increase perioperative risk:
- Diabetes mellitus: Increases cardiovascular complications and benefits from ACE inhibitor therapy long-term 4, 5
- Ischemic heart disease with prior MI: Strong indication for chronic ACE inhibitor therapy for secondary prevention 6, 5
- These conditions do NOT change the recommendation to hold ACE inhibitors preoperatively 2
Exception to Consider
The only scenario where continuing ACE inhibitors perioperatively might be considered is in patients with severe left ventricular systolic dysfunction (EF ≤40%) under very close hemodynamic monitoring, as cardioprotective benefits may outweigh hypotension risks 2. However, even in this population, the evidence remains uncertain 1.
Practical Management Algorithm
Preoperative (24 Hours Before Surgery)
- Hold the ACE inhibitor 1, 2
- Ensure adequate hydration status 2
- Continue other cardiac medications (beta-blockers must be continued to avoid withdrawal) 1
Intraoperative
- Anticipate potential need for vasopressors if hypotension occurs 1
- If hypotension develops and is attributed to ACE inhibitor effect, correct with volume expansion 3
Postoperative Restart Criteria
Restart ACE inhibitors when ALL of the following are met 1, 7, 2:
- Patient is hemodynamically stable
- Systolic blood pressure >100 mmHg 1
- Adequate volume status confirmed 7, 2
- Patient able to take oral medications
- No ongoing vasopressor requirements
The guideline states: "If ACE inhibitors are held before surgery, it is reasonable to restart as soon as clinically feasible postoperatively" 1.
Critical Pitfalls to Avoid
Do not abruptly discontinue beta-blockers or clonidine perioperatively - this causes rebound hypertension and is potentially harmful 1
Do not restart ACE inhibitors too early postoperatively - waiting for hemodynamic stability is essential to prevent postoperative hypotension 2
Do not forget to restart the ACE inhibitor - inappropriate discontinuation after surgery leads to worse long-term outcomes in patients with heart failure, hypertension, diabetes, and post-MI status 1
For this specific patient, long-term ACE inhibitor therapy is Class I indicated for secondary prevention after MI and for diabetes with cardiovascular disease 1, 5
Reconciling Conflicting Evidence
The apparent contradiction between the 2014 guideline's Class IIa recommendation to continue ACE inhibitors and the 2017 guideline's suggestion to discontinue them reflects evolving evidence. The newer, larger cohort studies published after 2014 provide stronger evidence favoring discontinuation 1, 2. The key distinction is:
- Older studies showed hypotension but no difference in hard outcomes (death, MI, stroke) 1
- The most recent large cohort study (2018) demonstrated actual reduction in composite adverse outcomes when ACE inhibitors were stopped 1, 2
Given this patient's high-risk profile (diabetes, ischemic heart disease, prior MI), the conservative approach of holding the ACE inhibitor 24 hours preoperatively minimizes immediate surgical risk while allowing prompt reinitiation for long-term cardiovascular protection 7, 2.