# Preoperative Angiotensin-Converting Enzyme Inhibitor Use and Its Effect on Intraoperative Hypotension in Non-cardiac Surgeries: A Meta-Analysis

## TL;DR

This study finds that stopping ACE inhibitors before non-cardiac surgery reduces intraoperative hypotension and need for vasopressors without increasing kidney injury risk.

## Contribution

A meta-analysis showing preoperative withholding of ACE inhibitors improves hemodynamic stability during non-cardiac surgery.

## Key findings

- Withholding ACE inhibitors preoperatively lowers intraoperative hypotension risk (OR = 0.62).
- Withholding reduces vasopressor use during surgery (OR = 0.64).
- No significant effect on postoperative acute kidney injury (OR = 0.92).

## Abstract

Angiotensin-converting enzyme inhibitors (ACE inhibitors) are widely prescribed for cardiovascular and renal conditions, and a large proportion of patients presenting for non-cardiac surgery are chronic users of these agents. However, the optimal perioperative management of ACE inhibitors remains controversial, particularly regarding their association with intraoperative hypotension. This meta-analysis aimed to systematically evaluate the effect of preoperative ACE inhibitor use on intraoperative hypotension and related perioperative outcomes in adult patients undergoing non-cardiac surgery. A comprehensive literature search of major electronic databases was performed to identify randomized controlled trials and observational studies comparing continuation versus withholding of ACE inhibitors before non-cardiac surgery. Studies reporting intraoperative hypotension or related hemodynamic outcomes were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed using the I² statistic and Cochran’s Q test. Five studies involving a total of 5,400 patients were included in the quantitative synthesis. Compared with continuation of ACE inhibitors, withholding these agents preoperatively was associated with a significantly lower incidence of intraoperative hypotension (pooled OR = 0.62, 95% CI: 0.52-0.74; p < 0.001), with moderate heterogeneity (I² = 41%). In addition, preoperative withholding of ACE inhibitors significantly reduced the requirement for intraoperative vasopressor support (pooled OR = 0.64, 95% CI: 0.52-0.80; p < 0.001), with low heterogeneity (I² = 24%). In contrast, no significant difference was observed between groups with respect to postoperative acute kidney injury (pooled OR = 0.92, 95% CI: 0.78-1.09; p = 0.33), and heterogeneity was negligible (I² = 0%). These findings indicate that withholding ACE inhibitors prior to non-cardiac surgery is associated with improved intraoperative hemodynamic stability and reduced vasopressor requirements, without a significant effect on postoperative acute kidney injury. Temporary preoperative discontinuation of ACE inhibitors may therefore be considered to minimize intraoperative hypotension in non-cardiac surgical patients, although individualized risk-benefit assessment remains essential.