Preoperative continuation of RAAS inhibitors in hypertensive patients undergoing non-cardiac surgery.

Background: There has been incongruent evidence on the outcomes relating to whether continuing or withholding renin-angiotensin-aldosterone system inhibitors (RAASi) preoperatively. This study aimed to systematically analyse the effect of preoperative RAASi on perioperative and postoperative outcomes in patients undergoing non-cardiac surgeries.

Method: PubMed, Scopus, ScienceDirect, and Cochrane databases were used with no limitation of the starting date, till 30th September 2024. The revised Cochrane risk-of-bias tool (RoB-2) and the Newcastle-Ottawa Scale (NOS) were used for quality assessment. The primary study outcomes were hemodynamic outcomes while the secondary outcomes included postoperative 30-day mortality, myocardial infarction, stroke and postoperative atrial fibrillation (POAF).

Results: Among 1,897 articles, 6 eligible randomized control trials and 6 observational studies were enrolled. The patients preoperatively continuing RAASi had a higher risk of intraoperative hypotension [OR (Odds Ratio) = 1.54; 95% CI (Confidence interval) = 1.31,1.82], along with lower systolic and diastolic blood pressures compared to those withholding RAASi. Postoperative complications including 30-day mortality, myocardial infarction, stroke, atrial fibrillation, acute kidney injury, septicemia, myocardial injury, postoperative hypertension and unplanned ICU admission, showed no significant differences. However, there was a marginal significance in lower POAF in the RAASi continuing group (OR = 0.73, 95% CI = 0.52, 1.02).

Conclusion: Withholding RAASi prior to non-cardiac operation significantly reduced the risk of intraoperative hypotension but may increase a chance to develop POAF without significant impact on 30-day mortality and other postoperative complications. Discontinuation of RAASi before non-cardiac surgery is recommended unless obligate indication.