Withholding renin–angiotensin system inhibitors before surgery appears to reduce hypotension

Two strategies compared in 10,773 patients

The researchers pooled five randomized trials comparing withholding versus continuing renin–angiotensin system inhibitors in patients undergoing surgery. Of the 10,773 participants, 5,388 had been assigned to the withholding group.

The question goes beyond blood pressure alone. Continuing these medications could increase the likelihood of hypotension around surgery. Conversely, withholding them raises concerns about significant hypertension or heart failure. The analysis sought to weigh these risks, excluding cardiac and vascular surgery.

Less hypotension, with moderate certainty

Perioperative hypotension was reported in 27.66% of patients in the withholding group, compared with 34.06% in the continuation group. The relative risk was 0.81, with a 95% confidence interval of 0.73 to 0.89. The authors rate the certainty of this finding as moderate.

For perioperative hypertension, the proportions were 9.46% versus 8.05%. However, uncertainty is too great to conclude that withholding treatment increases this risk: the certainty of the evidence is very low.

A major clinical benefit remains to be demonstrated

Reducing episodes of hypotension does not automatically mean preventing organ damage. Acute renal impairment affected 10.45% of patients when treatment was withheld, compared with 10.69% when it was continued. For acute heart failure, the proportions were 5.38% and 5.32%.

The results also do not establish a difference in myocardial infarction, stroke or arrhythmias. The certainty of the evidence for these complications is low. This lack of an established difference therefore does not prove that the two strategies are equivalent.

What this analysis tells us

Withholding treatment appears mainly to change the risk of hypotension around surgery. The abstract does not provide detailed withholding protocols, follow-up durations or results by treatment indication. It cannot guide an individual treatment decision.

If you take one of these medications and have surgery planned, the decision should be discussed with the team preparing you for the procedure. These results do not justify stopping your treatment on your own.

What we can take away

Withholding treatment probably reduces perioperative hypotension, but no benefit for major complications has been established. The decision still needs to be individualized with the medical team.