Should lisinopril (Angiotensin-Converting Enzyme (ACE) inhibitor) be withheld in a diabetic patient with a history of ischemic heart disease and previous myocardial infarction (heart attack) undergoing surgery to minimize the risk of intraoperative hypotension?

Clarification on Perioperative Lisinopril Management

In a diabetic patient with ischemic heart disease and previous myocardial infarction undergoing surgery, lisinopril should be withheld 24 hours before the procedure to minimize intraoperative hypotension risk, then restarted postoperatively once hemodynamically stable. This represents the current consensus based on the most recent high-quality evidence, despite the long-term cardiovascular benefits of ACE inhibitors in this population 1, 2.

Understanding the Apparent Contradiction

The confusion arises from distinguishing between chronic medical management versus perioperative management:

Long-Term Medical Management (Continue)

• Diabetic patients with prior MI have substantial mortality benefit from chronic ACE inhibitor therapy - the GISSI-3 trial demonstrated a 32% reduction in 6-week mortality (8.7% vs 12.4%) in diabetic patients with acute MI treated with lisinopril, saving 37 lives per 1000 treated patients 3
• This survival benefit persists at 6 months despite treatment withdrawal at 6 weeks (12.9% vs 16.1% mortality) 3
• ACE inhibitors are mandatory for secondary prevention in diabetic patients with ischemic heart disease, particularly those with previous MI 4, 5, 6

Perioperative Management (Withhold Temporarily)

• The European Society of Cardiology and American College of Cardiology recommend withholding ACE inhibitors 24 hours before surgery to reduce intraoperative hypotension risk 1, 2
• During anesthesia, ACE inhibitors block the compensatory renin-angiotensin-aldosterone system that maintains vascular tone when sympathetic nervous system is inhibited by anesthetics, baroreceptor control is lost, and relative hypovolemia exists from preoperative fasting 1
• Patients who discontinued ACE inhibitors 24 hours before surgery had lower risk of the primary composite outcome (death, stroke, myocardial injury) and less intraoperative hypotension compared to those continuing these medications 1, 7

Specific Management Algorithm

Preoperative Phase (24 Hours Before Surgery)

• Hold lisinopril the morning of surgery and 24 hours prior for major non-cardiac surgery 1, 2, 7
• The FDA label specifically warns that "in patients undergoing major surgery or during anesthesia with agents that produce hypotension, lisinopril may block angiotensin II formation secondary to compensatory renin release" 8
• This temporary discontinuation applies even to high-risk diabetic patients with prior MI, as the acute hypotension risk outweighs the brief interruption of chronic therapy 1

Intraoperative Management

• If hypotension occurs and is attributed to ACE inhibitor effect, correct with volume expansion 8
• Increased vasopressor requirements should be anticipated in patients who continued ACE inhibitors 1

Postoperative Restart Protocol

• Restart lisinopril when the patient is hemodynamically stable with systolic blood pressure >100 mmHg 1, 7
• Ensure adequate volume status before restarting to prevent postoperative hypotension 7
• The American College of Cardiology recommends restarting "as soon as clinically feasible postoperatively" 2
• Given the demonstrated 6-month mortality benefit in diabetic MI patients even after 6-week treatment withdrawal, prompt reinitiation is critical 3

Important Exception

For patients with systolic left ventricular dysfunction (ejection fraction ≤40%), the European Society of Cardiology recommends continuing ACE inhibitors perioperatively under close monitoring, as the cardioprotective benefit may outweigh hypotension risks in this specific subgroup 1, 7

Common Pitfalls to Avoid

• Do not confuse chronic indication with perioperative management - the strong indication for ACE inhibitors in diabetic patients with prior MI for long-term mortality reduction does not negate the need for temporary perioperative discontinuation 1, 3
• Avoid restarting too early postoperatively before volume status is adequate and hemodynamics are stable, as this can precipitate hypotension and renal dysfunction 7, 8
• Do not permanently discontinue - the survival benefit demonstrated in diabetic MI patients requires prompt reinitiation once safe 3
• The FDA label notes that diabetic patients with acute MI treated with lisinopril had higher incidence of hypotension (by 5.3%) and renal dysfunction (by 1.3%), emphasizing the need for careful perioperative monitoring 8

Evidence Quality Assessment

The recommendation to withhold ACE inhibitors perioperatively is based on recent large cohort studies and meta-analyses from 2018 showing reduced composite outcomes and intraoperative hypotension 1. This represents higher-quality, more recent evidence than older guidelines suggesting continuation. The 2023 American Diabetes Association guidelines acknowledge this evolving evidence by stating that "in select patients with controlled blood pressure undergoing elevated-risk non-cardiac surgery, omission of RAAS inhibitors 24 hours before surgery may be beneficial" 9.