Prospective Randomized Evaluation of Preoperative Angiotensin-Converting Enzyme Inhibition (PREOP-ACEI)
BACKGROUND: Intraoperative hypotension is associated with an increased risk of end organ damage and death. The transient preoperative interruption of angiotensin-converting enzyme inhibitor (ACEI) therapy prior to cardiac and vascular surgeries decreases the occurrence of intraoperative hypotension.
OBJECTIVE: We sought to compare the effect of two protocols for preoperative ACEI management on the risk of intraoperative hypotension among patients undergoing noncardiac, nonvascular surgeries.
DESIGN: Prospective, randomized study.
SETTING: Midwestern urban 489-bed academic medical center.
PATIENTS: Patients taking an ACEI for at least six weeks preoperatively were considered for inclusion.
INTERVENTIONS: Randomization of the final preoperative ACEI dose to omission (n = 137) or continuation (n = 138).
MEASUREMENTS: The primary outcome was intraoperative hypotension, which was defined as any systolic blood pressure (SBP) < 80 mm Hg. Postoperative hypotensive (SBP < 90 mm Hg) and hypertensive (SBP > 180 mm Hg) episodes were also recorded. Outcomes were compared using Fisher’s exact test.
RESULTS: Intraoperative hypotension occurred less frequently in the omission group (76 of 137 [55%]) than in the continuation group (95 of 138 [69%]) (RR: 0.81, 95% CI: 0.67 to 0.97, P = .03, NNH 7.5). Postoperative hypotensive events were also less frequent in the ACEI omission group (RR: 0.49, 95% CI: 0.28 to 0.86, P = .02) than in the continuation group. However, postoperative hypertensive events were more frequent in the omission group than in the continuation group (RR: 1.95, 95%: CI: 1.14 to 3.34, P = .01).
CONCLUSION: The transient preoperative interruption of ACEI therapy is associated with a decreased risk of intraoperative hypotension.
REGISTRATION: ClinicalTrials.gov: NCT01669434.
© 2018 Society of Hospital Medicine
CONCLUSION
Hypertension is among the most common chronic conditions encountered in patients planning surgery, and ACEIs are among the most frequently prescribed antihypertensive medications. This study showed that ACEI continuation is associated with an increased frequency and cumulative duration of intraoperative hypotension. These findings, while at odds with current ACC/AHA guidelines, align with the findings of a meta-analysis on this subject and with recent literature.3,11-13,22
Acknowledgments
The authors wish to thank Miranda M Fricke, MS, PA-C; Tiffany K Hillyard, APRN-FNP; and Barbara Sink, MPAS, PA-C who assisted in the design and conduct of patient enrollment and randomization procedures.
Disclosures
The authors have no relevant financial conflicts of interest to report.
Funding
This study was subsidized by a grant from the University of Nebraska Medical Center Research Support Fund. The funding source had no role in the design, conduct, analysis, or reporting of the study.
