Patients who did not take their ACEI or ARB on the day of surgery did not have a greater incidence of intraoperative or postoperative hypertension. (Image source: Thinkstock)

Patients who did not take their ACEI or ARB on the day of surgery did not have a greater incidence of intraoperative or postoperative hypertension. (Image source: Thinkstock)

Should antihypertensives be discontinued before surgery?  No.  Is it harmful for those patients who take chronic angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II subtype I receptor agonists (ARBs) to stop taking the medications before surgery?  Maybe.  There is some evidence that if patients continue to use these drugs, on the morning of surgery they may be hypotensive intraoperatively or have greater hemodynamic instability.

Dr. Rebecca S. Twersky, Department of Anesthesiology, SUNY Downstate Medical Center, Brooklyn, New York, and coauthors randomized more than 500 ambulatory or same-day surgery patients to either continue or discontinue their ACEIs or ARBs on the day of surgery.  Their results appear in the article “The Risk of Hypertension after Preoperative Discontinuation of Angiotensin-Converting Enzyme Inhibitors or Angiotensin Receptor Antagonists in Ambulatory and Same-Day Admission Patients,” which is published in this month’s edition of Anesthesia & Analgesia.

All patients were receiving ACEIs or ARBs primarily for hypertension treatment.  Patients who did not take their ACEI or ARB on the day of surgery did not have a greater incidence of intraoperative or postoperative hypertension, nor did they have increased cancellations or hospital admissions.  Similarly, patients who continued treatment were not more hypotensive intra- or postoperatively.

It’s difficult to know whether patients who discontinued the drug before surgery had more long-term cardiac or other issues.   It’s also interesting that although some recommend stopping these drugs because of the risk of hypotension after anesthesia induction, the actual effect of discontinuation has not been studied until now.  Why should the risk of hypotension be greater for patients taking these medications on the day of surgery and who undergo coronary artery bypass grafting or major vascular procedures compared to patients who undergo ambulatory surgical procedures, and who presumably also have similar risk factors?

These data suggest that those who recommend discontinuing these drugs should modify preoperative instructions regarding their use for those patients undergoing ambulatory surgical procedures.