Perioperative discontinuation of renin–angiotensin system inhibitors in non-cardiac surgery: is it time to change what we tell our patients?

How should recommendations regarding perioperative discontinuation vs continuation of renin-angiotensin system inhibitors (RASIs), in patients undergoing non-cardiac surgery, change, consistently with the change in evidence? The 2022 European Society of Cardiology guidelines suggested that withholding RASIs on the day of surgery may be considered to prevent perioperative hypotension, mainly based on observational studies and small randomized controlled trials (RCTs) showing an association between discontinuation of RASIs and lower risk of perioperative hypotension. New evidence coming from large international RCTs has confirmed that the perioperative discontinuation compared with continuation of RASIs leads to a reduction of perioperative hypotension but limited to intraoperative hypotension, with no effect on post-operative hypotension (which is what likely drives clinical outcomes); moreover, new RCTs have demonstrated no effect on patient-important outcomes. Rather than strengthening the recommendation in favour of perioperative discontinuation of RASIs only based on the effect on intraoperative hypotension (surrogate outcome), this new trial evidence support that both strategies are viable options, if there are awareness of the risk of intraoperative hypotension and tools to monitor and counteract it in the operating room. A RASI discontinuation strategy could be the appropriate choice in situations with increased risk of more severe intraoperative hypotension (e.g., patient has an unusually low pre-operative blood pressure, or surgery is one typically associated with large blood loss).