Preoperative Continuation of RAAS Inhibitors in Hypertensive Patients Undergoing Noncardiac Surgery

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 analyze the effect of preoperative RAASi on perioperative and postoperative outcomes in patients undergoing noncardiac surgeries.

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 were used for quality assessment. The primary study outcomes were hemodynamic outcomes while the secondary outcomes included postoperative 30-day mortality, myocardial infarction (MI), stroke and postoperative atrial fibrillation (POAF).

Among 1897 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, MI, 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).

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