Purpose: To determine whether preoperative renin-angiotensin system (RAS) inhibitor use within 7 days of noncardiac surgery is associated with a lower incidence of postoperative acute kidney injury (AKI) in hypertensive patients.
Materials and methods: We retrospectively analyzed 12,545 hypertensive patients undergoing noncardiac surgery at the Third Xiangya Hospital of Central South University from February 2007 to November 2015. According to the use of RAS inhibitors within 7 days of surgery, the patients were divided into a RASI group and a non-RASI group. We used a multivariable logistic regression model and propensity score matching (PSM) analysis to examine the association between preoperative RAS inhibitor use and postoperative AKI incidence.
Results: Among the 12,545 hypertensive patients undergoing noncardiac surgery who met the inclusion/exclusion criteria, 18.74% received preoperative RAS inhibitor treatment within 7 days of surgery. After PSM, 2,192 patients in each group were matched successfully. The incidence of postoperative AKI in the RASI group was significantly lower than that in the non-RASI group (7.39% vs. 12.32%, p < 0.001). The multivariable logistic regression analysis and the PSM analysis demonstrated similar associations between preoperative RAS inhibitor use and postoperative AKI incidence. This association was modified by the presence of preoperative congestive heart failure (CHF) (p-value for the interaction: 0.027), and the observed association was not evident in patients without CHF (CHF: adjusted odds ratios (ORs): 0.47; 95% CI: 0.31 - 0.70 vs. no CHF: adjusted OR: 0.80; 95% CI: 0.62 - 1.03).
Conclusion: The preoperative use of RAS inhibitors in hypertensive patients was associated with a lower incidence of AKI following noncardiac surgery, and this association was not significant in the subgroup population without CHF. .