For an adult undergoing non‑cardiac surgery, should the angiotensin‑converting‑enzyme inhibitor be held on the day of surgery, and when can it be safely restarted postoperatively?

Perioperative Management of ACE Inhibitors for Non-Cardiac Surgery

Primary Recommendation

For adults undergoing non-cardiac surgery who are taking ACE inhibitors for hypertension, hold the medication 24 hours before surgery; for patients with left ventricular systolic dysfunction, continue the ACE inhibitor perioperatively with close hemodynamic monitoring. 1, 2

Preoperative Management Strategy

For Hypertensive Patients (Without Heart Failure)

• Discontinue ACE inhibitors 24 hours before surgery to reduce the risk of severe intraoperative hypotension, particularly following anesthetic induction 1, 2
• Ensure blood pressure remains well-controlled (consistently <180/110 mmHg) after discontinuation 2
• The risk of severe hypotension is particularly elevated when ACE inhibitors are combined with beta-blockers 1

Evidence supporting discontinuation: Patients taking ACE inhibitors within 10 hours of surgery have a 74% increased odds of moderate hypotension (systolic BP ≤85 mmHg) during the first 30 minutes after induction compared to those who stopped ≥10 hours before surgery 3. A systematic review confirmed that continuing ACE inhibitors increases intraoperative hypotension risk (OR 0.63 for withholding, 95% CI 0.47-0.85) without demonstrating any mortality or major adverse cardiac event benefit from continuation 4.

For Patients With Left Ventricular Systolic Dysfunction

• Continue ACE inhibitors perioperatively as the cardioprotective benefits outweigh hypotension risks in this population 1
• Implement close hemodynamic monitoring and have vasopressors readily available 1

Common Pitfall to Avoid

Do not abruptly discontinue ACE inhibitors in patients also taking beta-blockers or clonidine, as this combination increases the risk of rebound hypertension 2. If both medications are prescribed, coordinate discontinuation timing carefully or consider continuing the ACE inhibitor with enhanced monitoring.

Intraoperative Considerations

• Anticipate that 50% of patients who took ACE inhibitors on the day of surgery will experience transient intraoperative hypotension 5
• Have vasopressors immediately available, as ACE inhibitor use may impair the response to standard vasopressor therapy 2
• Despite increased hypotension risk, meta-analyses show no difference in mortality, major adverse cardiac events, acute kidney injury, or stroke between continuation and withholding strategies 4

Postoperative Resumption

Restart ACE inhibitors as soon as the patient is euvolemic and clinically stable postoperatively, typically within 24 hours after surgery. 5, 1, 2

Specific Criteria for Safe Resumption

• Confirm adequate volume status before restarting to minimize risk of postoperative renal dysfunction 5, 2
• Ensure patient is tolerating oral medications 2
• Verify hemodynamic stability without ongoing vasopressor requirements 2

Critical timing consideration: Delaying resumption of ACE inhibitors beyond 24-48 hours postoperatively has been associated with increased 30-day mortality risk, emphasizing the importance of timely restart 2. The ACC/AHA guidelines provide a Class IIa recommendation (Level of Evidence C) that it is reasonable to restart ACE inhibitors as soon as clinically feasible postoperatively 5.

Evidence Quality and Guideline Consensus

The 2014 ACC/AHA guidelines provide a Class IIa recommendation (Level of Evidence B) that continuation of ACE inhibitors perioperatively is reasonable, but also state it is reasonable to restart them postoperatively once euvolemic 5. However, the more recent European Society of Cardiology guidance (reflected in current practice summaries) provides clearer differentiation: hold for hypertension, continue for heart failure 1, 2.

Key limitation: No large-scale randomized controlled trial has definitively established whether continuation or withholding is superior for patient-centered outcomes. The available evidence shows increased hypotension with continuation but no difference in mortality or major complications 4. Multiple ongoing trials are addressing this question 6, 7.

Clinical Decision Algorithm

1. Identify indication: Is the ACE inhibitor prescribed for hypertension alone or for left ventricular systolic dysfunction/heart failure?
2. For hypertension: Hold 24 hours before surgery 1, 2
3. For LV dysfunction/heart failure: Continue perioperatively with enhanced monitoring 1
4. Ensure euvolemia: Verify adequate volume status before surgery if holding, and before restarting postoperatively 5, 2
5. Resume early: Restart within 24 hours postoperatively once stable and euvolemic 5, 1, 2