What is the recommended preoperative management of beta-blockers, statins, Angiotensin-Converting Enzyme inhibitors (ACEi), Angiotensin II Receptor Blockers (ARB), and Angiotensin Receptor-Neprilysin Inhibitors (ARNi) such as sacubitril/valsartan before Coronary Artery Bypass Grafting (CABG)?

Preoperative Medication Management Before CABG

Beta-blockers should be administered for at least 24 hours before CABG to all patients without contraindications, statins should be continued without interruption, and ACE inhibitors/ARBs should be held on the day of surgery due to potential intraoperative hypotension risk. 1

Beta-Blockers

• Preoperative administration: Beta-blockers should be administered for at least 24 hours before CABG to all patients without contraindications to reduce the incidence of postoperative atrial fibrillation 1
• Continuation: Should be reinstituted as soon as possible postoperatively once the patient is hemodynamically stable 1, 2
• Evidence strength: Class I recommendation with Level of Evidence B 1
• Benefit: Reduces incidence of postoperative atrial fibrillation and may reduce perioperative mortality 1
• Caution: In patients with severely reduced left ventricular ejection fraction (<30%), beta-blockers should be used cautiously as they may not provide the same mortality benefit 3

Statins

• Preoperative management: All patients undergoing CABG should receive statin therapy preoperatively unless contraindicated 1
• Continuation: Statins should NOT be discontinued before or after CABG in patients without adverse reactions to therapy (Class III: HARM recommendation) 1
• Dosing goal: Use adequate dose to reduce LDL cholesterol to <100 mg/dL and achieve at least 30% LDL reduction 1
• Evidence strength: Class I recommendation with Level of Evidence A 1

ACE Inhibitors/ARBs/ARNIs

• Preoperative management: The safety of preoperative administration of ACE inhibitors or ARBs is uncertain (Class IIb recommendation) 1
• Concerns: Associated with intraoperative hypotension, blunted response to vasopressors, and potential for severe post-CPB hypotension (vasoplegia syndrome) 1
• Recommendation: Consider holding ACE inhibitors/ARBs on the day of surgery to avoid intraoperative hypotension
• Postoperative resumption: Should be reinstituted once the patient is stable postoperatively, unless contraindicated 1
• ARNIs: While not specifically addressed in guidelines, these medications contain an ARB component (valsartan in sacubitril/valsartan) and should be managed similarly to ARBs

Antiplatelet Therapy

• Aspirin: Should be administered to CABG patients preoperatively (100-325 mg daily) 1
• P2Y12 inhibitors:
  • Clopidogrel and ticagrelor: Discontinue at least 5 days before elective CABG 1
  • Prasugrel: Discontinue at least 7 days before elective CABG 1
  • For urgent CABG: Discontinue clopidogrel and ticagrelor for at least 24 hours 1
• Glycoprotein IIb/IIIa inhibitors: Discontinue eptifibatide/tirofiban 2-4 hours before surgery and abciximab at least 12 hours before 1

Clinical Algorithm for Preoperative Medication Management

1. Beta-blockers:

   • Continue in all patients without contraindications
   • Administer for at least 24 hours before surgery
   • Use with caution in patients with LVEF <30%

2. Statins:

   • Continue without interruption in all patients
   • Do not discontinue before surgery

3. ACE inhibitors/ARBs/ARNIs:

   • Hold on the day of surgery
   • Plan to reinstitute postoperatively once patient is stable

4. Antiplatelet therapy:

   • Continue aspirin
   • Discontinue P2Y12 inhibitors according to specific timeframes
   • Discontinue glycoprotein IIb/IIIa inhibitors according to specific timeframes

Common Pitfalls and Caveats

• Failure to restart beta-blockers early enough postoperatively may increase risk of atrial fibrillation 2
• Inappropriate discontinuation of statins before CABG can increase perioperative risk 1
• Continuing ACE inhibitors/ARBs on the day of surgery may lead to significant intraoperative hypotension and vasoplegia syndrome 1
• Inadequate antiplatelet management can lead to either excessive bleeding (if not discontinued appropriately) or increased thrombotic risk (if discontinued for too long) 1

By following these evidence-based recommendations, perioperative morbidity and mortality can be optimized for patients undergoing CABG surgery.