Is it appropriate to continue nitroglycerin 2.6 mg and aspirin (acetylsalicylic acid) 75 mg until 12 hours before coronary artery bypass grafting?

Perioperative Management of Nitroglycerin and Aspirin Before CABG

Continue both nitroglycerin 2.6 mg and aspirin (Ecosprin) 75 mg until 12 hours before coronary artery bypass surgery—this approach is appropriate and recommended.

Aspirin Management Before CABG

The evidence strongly supports continuing aspirin perioperatively for CABG patients. Aspirin should be continued up until the day of surgery 1. The 2011 ACC/AHA CABG guidelines give a Class I recommendation (Level of Evidence B) that aspirin 100-325 mg daily should be administered to CABG patients preoperatively 1. Your dose of 75 mg falls within the therapeutic range and stopping it 12 hours before surgery provides an appropriate safety margin.

Key Evidence for Aspirin Continuation:

• The 2024 AHA/ACC guidelines recommend continuing aspirin (75-100 mg) in patients with prior PCI undergoing surgery to reduce cardiac events 2
• The 2012 ACCP guidelines suggest continuing aspirin around the time of CABG surgery rather than stopping it 7-10 days before 3
• A 2024 meta-analysis of 15 randomized controlled trials with 6,188 patients found no significant difference in mortality, myocardial infarction, or postoperative blood loss between patients who continued versus stopped aspirin before CABG 4
• An 8,000+ patient cohort study showed aspirin use within 5 days prior to CABG reduced overall mortality without increasing reoperation risk for bleeding 5

Balancing Bleeding vs. Thrombotic Risk:

While some older studies suggested increased bleeding with continued aspirin, the most recent high-quality evidence shows:

• Modest increases in chest tube drainage (mean difference 143 mL) 6
• No significant increase in surgical re-exploration rates 4, 6
• The cardiovascular protective benefits outweigh minimal bleeding risks 1, 5

Important caveat: If your surgery must be delayed and clopidogrel or other P2Y12 inhibitors are being used, those should be stopped at least 5 days before elective CABG 1. However, aspirin alone can and should be continued.

Nitroglycerin Management Before CABG

Nitroglycerin can be safely continued until 12 hours before surgery. The FDA labeling for nitroglycerin does not contraindicate perioperative use 7. In fact, nitroglycerin has been studied as a prophylactic infusion during CABG surgery itself, demonstrating safety in the operative setting 8.

Clinical Considerations for Nitroglycerin:

• The primary concern with nitroglycerin is hypotension, particularly in volume-depleted patients 7
• Stopping 12 hours preoperatively allows adequate clearance (nitroglycerin has a short half-life of 1-4 minutes)
• There is no guideline recommendation requiring prolonged discontinuation of nitrates before cardiac surgery
• The drug can precipitate angina if withdrawn abruptly in patients with chronic exposure, so gradual tapering or continuation until shortly before surgery is actually preferable 7

Drug Interaction Alert:

The FDA labeling emphasizes that nitroglycerin's vasodilatory effects may be enhanced by aspirin 7. However, this interaction is not contraindicated—it simply requires monitoring for hypotension. In your case, stopping both medications 12 hours before surgery provides an appropriate safety window.

Practical Algorithm for Your Situation:

1. Continue aspirin 75 mg daily until 12 hours before surgery (Class I recommendation)
2. Continue nitroglycerin 2.6 mg until 12 hours before surgery (safe based on pharmacokinetics and FDA labeling)
3. Ensure adequate hydration before surgery to minimize hypotension risk from nitroglycerin
4. Resume aspirin within 24-48 hours after CABG to improve graft patency 1
5. Coordinate with your surgical and anesthesia teams regarding the exact timing, as institutional protocols may vary slightly

Common Pitfalls to Avoid:

• Do not stop aspirin 5-7 days before elective CABG—this outdated practice increases thrombotic risk without proven bleeding benefit
• Do not confuse aspirin management with P2Y12 inhibitor management—clopidogrel/prasugrel/ticagrelor require longer discontinuation periods (5-7 days), but aspirin does not 1
• Do not abruptly discontinue nitroglycerin days before surgery—this can precipitate rebound angina in chronic users 7

Your proposed 12-hour discontinuation window for both medications represents a reasonable, evidence-based approach that balances cardiovascular protection with perioperative safety.