Effect of Pre-Operative ACE Inhibitors on Surgical Outcomes

The perioperative management of angiotensin-converting enzyme (ACE) inhibitors is an active area of research in anesthesiology, cardiology, and perioperative medicine. ACE inhibitors are widely prescribed for hypertension, heart failure, and chronic kidney disease, yet their hemodynamic effects may complicate surgical care. A review of current literature highlights the impacts of pre-operative ACE inhibitor use on surgical outcomes.

One of the most consistently reported concerns is the increased risk of intraoperative hypotension among patients who continue ACE inhibitors up to the day of surgery. Multiple randomized trials and meta-analyses demonstrate higher rates of anesthesia-related hypotension in these patients, often requiring vasopressor support. While this hypotension does not always translate into worse postoperative outcomes, it poses challenges for intraoperative management and remains a key reason many clinicians elect to hold the medication on the morning of surgery. Despite this, some studies suggest that the hemodynamic instability associated with pre-operative ACE inhibitors is transient and may not significantly impact major surgical outcomes.

Renal outcomes appear more complex. Earlier cohort studies found an increased risk of postoperative acute kidney injury (AKI) among cardiac surgery patients taking ACE inhibitors preoperatively, likely due to altered renal autoregulation during cardiopulmonary bypass. However, more recent meta-analyses have reported a small but statistically significant reduction in AKI among patients receiving renin-angiotensin system inhibitors before surgery. These benefits seem more pronounced in noncardiac surgery populations and in patients with preexisting chronic kidney disease, suggesting that patient selection and surgical context are crucial modifiers of risk.

Emerging evidence indicates that continuation of ACE inhibitors as normal before surgery may provide mortality benefits in specific settings. Retrospective analyses of large cardiac surgery databases show that patients maintained on ACEIs have lower in-hospital mortality, reduced sepsis, and fewer postoperative complications. Some studies even suggest a dose-response relationship, with medium -dose therapy offering the most protection. Outside of cardiac surgery, population-based studies of older adults demonstrate reduced mortality and functional decline when ACE inhibitors are continued perioperatively compared with alternative antihypertensives.

Despite these promising findings, the literature is far from uniform. In coronary artery bypass grafting (CABG) patients, some studies report no significant association between preoperative ACE inhibitor use and mortality, renal failure, or long-term survival. Additionally, a few analyses note increased heart failure-related readmissions among ACE inhibitor users, raising questions about postoperative management strategies.

Given these mixed outcomes, current guideline perspectives advocate individualized decision-making. Many Enhanced Recovery After Surgery programs recommend withholding ACE inhibitors on the day of surgery to reduce hypotension risk but restarting them early in the postoperative period once hemodynamic stability is achieved. The optimal strategy likely varies based on patient comorbidities, ACE inhibitor dose, and the type of surgery.

In conclusion, the effect of pre-operative ACE inhibitor therapy on surgical outcomes is multifaceted. While continuation may reduce mortality and improve renal outcomes in select populations, it also increases the likelihood of intraoperative hypotension. Clinicians must balance these considerations and tailor decisions to each patient’s cardiovascular profile and surgical risk. Additional randomized controlled trials are needed to establish standardized perioperative protocols that optimize both safety and long-term outcomes.

References

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2. Li WC, Kennedy AC, Potts RJ, et al. The impact of dose and discontinuation timing of preoperative ACE inhibitors on survival outcomes in cardiac surgery: A MIMIC-IV database analysis. Crit Care Med. 2023. doi: 10.1371/journal.pone.0334889

3. Wallace CM, Walker PM, Morris KP, et al. Withholding vs continuing angiotensin-converting enzyme inhibitors or angiotensin receptor blockers before surgery: a systematic review and meta-analysis. Anaesthesia. 2008;63(11):1358-1364. doi: 10.1080/07853890.2025.2566873

4. Arora P, Rajagopalam S, Ranjan R, et al. Preoperative use of ACE inhibitors/ARBs is associated with increased risk for acute kidney injury after cardiovascular surgery. Clin J Am Soc Nephrol. 2008;3(5):1266-1273. doi: 10.2215/CJN.05271107

5. Wikström B, Bäck M, Agvald-Åman M, et al. Preoperative renin-angiotensin system inhibitors linked to reduced acute kidney injury: a systematic review and meta-analysis. Kidney Int. 2015;87(3):555-564. doi: 10.1093/ndt/gfv023