A Systematic Review of Outcomes Associated With Withholding or Continuing Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Before Noncardiac Surgery

BACKGROUND: The global rate of major noncardiac surgical procedures is increasing annually, and of those patients presenting for surgery, increasing numbers are taking either an angiotensin-converting enzyme inhibitor (ACE-I) or an angiotensin receptor blocker (ARB). The current recommendations of whether to continue or withhold ACE-I and ARB in the perioperative period are conflicting. Previous meta-analyses have linked preoperative ACE-I/ARB therapy to the increased incidence of postinduction hypotension; however, they have failed to correlate this with adverse patient outcomes. The aim of this meta-analysis was to determine whether continuation or withholding ACE-I or ARB therapy in the perioperative period is associated with mortality and major morbidity. METHODS: This meta-analysis was prospectively registered on PROSPERO (CRD42017055291). A comprehensive search of MEDLINE (PubMed), CINAHL (EBSCO host), ProQuest, Cochrane database, Scopus, and Web of Science was conducted on December 6, 2016. We included adult patients > 18 years of age on chronic ACE-I or ARB therapy who underwent noncardiac surgery in which ACE-I or ARB was either withheld or continued on the morning of surgery. Primary outcomes included all-cause mortality and major cardiac events (MACE). Secondary outcomes included the risk of congestive heart failure, acute kidney injury, stroke, intraoperative/postoperative hypotension, and the length of hospital stay. RESULTS: After abstract review, the full text of 25 studies was retrieved, of which 9 fulfilled the inclusion criteria: 5 were randomized control trials, and 4 were cohort studies. These studies included a total of 6022 patients on chronic ACE-I/ARB therapy before noncardiac surgery. A total of 1816 patients withheld treatment the morning of surgery and 4206 continued their ACE-I/ARB. Preoperative demographics were similar between the 2 groups. Withholding ACE-I/ARB therapy was not associated with a difference in mortality (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.62-1.52; I-2 = 0%) or MACE (OR, 1.12; 95% CI, 0.82-1.52; I-2 = 0%). However, withholding therapy was associated with significantly less intraoperative hypotension (OR, 0.63; 95% CI, 0.47-0.85; I-2 = 71%). No effect estimate could be pooled concerning length of hospital stay and congestive heart failure. CONCLUSIONS: This meta-analysis did not demonstrate an association between perioperative administration of ACE-I/ARB and mortality or MACE. It did, however, confirm the current observation that perioperative continuation of ACE-I/ARBs is associated with an increased incidence of intraoperative hypotension. A large randomized control trial is necessary to determine the appropriate perioperative management of ACE-I and ARBs.