Publications of the Week: Preoperative RASIs: Stop or not?

Background: There is uncertainty as to the best strategy for managing patients who are taking renin-angiotensin system inhibitors (RASIs)—comprising angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs)—and require an elective surgery, specifically whether to continue or interrupt RASIs perioperatively. This study assessed if continuation versus interruption of RASIs before major noncardiac surgery results in decreased postoperative complications.

Methods: A randomized controlled trial was conducted among patients who were receiving a RASI for ?3 months and were scheduled to undergo a major noncardiac surgery. Patients were allocated to continue RASIs until the day of surgery or to interrupt RASIs 48 hours before surgery, with the last dose 3 days before surgery. The primary outcome was a composite of all-cause mortality and major postoperative complications within 28 days after surgery. Secondary outcomes within 28 days postoperatively included intraoperative hypotension during surgery, acute kidney injury, postoperative organ failure, and length of stay in the hospital and intensive care unit.

Results: There were 2222 patients (mean age, 67 years; 65% male) randomized, of whom 46% were receiving an ACEI and 54% were receiving an ARB. The rate of all-cause mortality and major postoperative complications was 22% (245/1115) in the interruption group and 22% (247/1107) in the continuation group (risk ratio [RR], 1.02; 95% CI, 0.87-1.19). Intraoperative hypotension occurred in 41% in the interruption group and in 54% in the continuation group (RR, 1.31; 95% CI, 1.19-1.44). There were no other differences in the trial outcomes.

Conclusions: Among patients who had a major noncardiac surgery, a continuation strategy of RASIs before surgery was not associated with a higher rate of postoperative complications than a discontinuation strategy.

McMaster editors’ commentary: The prevailing practice has been to stop RASIs before surgery based on the premise that this will reduce intraoperative hypotension and, in turn, adverse cardiovascular events. This trial adds to the results of the POISE-3 trial, indicating that perioperative RASI management, whether continuation or interruption, does not affect the likelihood that patients will develop major postoperative outcomes. These results allow flexibility in perioperative clinical management, for example, allowing surgery to proceed if a patient unexpectedly continued RASI therapy. Knowledge that RASI continuation is associated with higher rates of intraoperative hypotension will allow anesthesiologists to anticipate this outcome and manage patients accordingly.