Does withholding an ACE inhibitor or ARB before surgery improve outcomes?
EVIDENCE-BASED ANSWER:
A guarded yes, because the evidence of benefit is from observational studies and applies to noncardiac surgery. Withholding angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) 24 hours before noncardiac surgery has been associated with a 30-day lower risk for all-cause death, stroke, myocardial injury, and intraoperative hypotension (18% adjusted relative risk reduction).
The finding is based on 1 international prospective cohort study and, of note, is an association and a likelihood of benefit. Confirmation would require a large randomized trial (RCT; strength of recommendation [SOR]: B, good-quality international prospective cohort study).
RECOMMENDATIONS
The 2014 American College of Cardiology/American Heart Association Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery states that continuing ACEIs or ARBs perioperatively is reasonable (class IIa recommendation [moderate benefit of treatment relative to risk]; level of evidence [LOE], B [data from limited populations and single randomized or nonrandomized trials]). 5
The guideline also recommends that if ACEIs or ARBs are held before surgery, it is reasonable to restart them as soon as clinically feasible postoperatively (class IIa recommendation; LOE, C [data from very limited populations and consensus opinion or case studies]).
Editor’s Takeaway
The results of the large prospective cohort contradict those of previous smaller, methodologically weaker studies, and the new findings should be taken seriously.1 Nevertheless, selection bias (why did investigators stop the ACEI?) remains. Until we have a large RCT, the preop question to ask may be why not stop the ACEI?
