What medications should be administered to prepare a patient for diagnostic coronary angiography and possible percutaneous coronary intervention (angioplasty)?

Medication Preparation for Coronary Angiography and Angioplasty

All patients undergoing coronary angiography with possible PCI should receive aspirin (81-325 mg if already on daily therapy, or 325 mg nonenteric if not) before the procedure, and a P2Y12 inhibitor loading dose should be administered to those undergoing PCI with stenting. 1, 2

Antiplatelet Therapy Protocol

Aspirin Administration

For patients already on daily aspirin:

• Give 81-325 mg before PCI 1, 2
• Continue indefinitely after PCI 1

For aspirin-naive patients:

• Administer nonenteric aspirin 325 mg before PCI 1, 2
• Older guidelines suggested giving 300-325 mg at least 2 hours (preferably 24 hours) before the procedure 3, 4, but current practice emphasizes administration before the procedure without strict timing requirements

P2Y12 Inhibitor Selection and Timing

The choice and timing of P2Y12 inhibitor depends critically on clinical presentation:

For Elective PCI (Stable Ischemic Heart Disease):

• Do NOT routinely pretreat with P2Y12 inhibitors before diagnostic angiography 5
• Administer clopidogrel 600 mg loading dose in the catheterization laboratory once PCI is decided 2, 5
• This approach avoids unnecessary bleeding risk in patients who may require CABG or have no significant disease

For ACS (NSTEMI/Unstable Angina):

• If angiography expected ≤24 hours: Do NOT routinely pretreat 5
• If angiography expected >24 hours: Pretreat with P2Y12 inhibitor 5
• Loading dose options for ACS patients undergoing PCI:
  • Clopidogrel 600 mg (ACS and non-ACS) 2
  • Prasugrel 60 mg (ACS only) 2
  • Ticagrelor 180 mg (ACS only) 2

For STEMI after fibrinolytic therapy:

• Clopidogrel 300 mg if within 24 hours of fibrinolysis 1, 2
• Clopidogrel 600 mg if >24 hours after fibrinolysis 1, 2

Critical contraindication: Prasugrel should NOT be given to patients with prior stroke or TIA 1

Anticoagulation During PCI

Unfractionated Heparin (UFH):

• Standard anticoagulant for PCI 2
• Continue during procedure 6

Bivalirudin:

• Useful alternative with or without prior UFH treatment 2
• May reduce bleeding compared to UFH plus GP IIb/IIIa inhibitors

Enoxaparin:

• If patient received <2 therapeutic subcutaneous doses or last dose was 8-12 hours before PCI: give additional 0.3 mg/kg IV 2
• Do NOT give UFH to patients on therapeutic enoxaparin - risk of excessive anticoagulation 2

Fondaparinux:

• Should NOT be used as sole anticoagulant - requires additional anti-IIa agent due to catheter thrombosis risk 2

Glycoprotein IIb/IIIa Inhibitors

For STEMI (Primary PCI):

• Reasonable to administer GP IIb/IIIa inhibitor (abciximab, double-bolus eptifibatide, or high-bolus tirofiban) with UFH, regardless of clopidogrel pretreatment 2
• Do NOT routinely give upstream (before catheterization laboratory) 2

For NSTEMI/Unstable Angina:

• Give GP IIb/IIIa inhibitor if high-risk features (elevated troponin), NOT treated with bivalirudin, and NOT adequately pretreated with clopidogrel 2
• If adequately pretreated with clopidogrel: reasonable but not mandatory 2

Procedural Sedation Considerations

Pre-procedure assessment:

• Evaluate for difficult intubation predictors 1
• Establish free-flowing IV line 1

Monitoring requirements:

• Dedicated personnel for sedation monitoring
• Continuous monitoring: consciousness level, respiratory rate, blood pressure, cardiac rhythm, oxygen saturation 1

Available equipment:

• High-flow oxygen source
• Suction and airway management equipment
• Defibrillator
• Resuscitation drugs and reversal agents 1

Note: Routine premedication with benzodiazepines (diazepam) and antihistamines (chlorpheniramine) does NOT reduce anxiety or pain and may increase local pain - not recommended 7

Special Populations

Contrast allergy:

• Pretreat with oral corticosteroids and H1-receptor blockers 8

Renal insufficiency:

• Aggressive hydration to minimize contrast nephropathy risk 8

Diabetics on metformin with renal failure:

• Discontinue metformin before procedure
• Restart only after confirming normal creatinine 8

Common Pitfalls to Avoid

1. Do NOT pretreat elective PCI patients with P2Y12 inhibitors before knowing coronary anatomy - increases bleeding risk if CABG needed 5

2. Do NOT combine UFH with therapeutic enoxaparin - excessive anticoagulation 2

3. Do NOT use fondaparinux alone - add anti-IIa agent 2

4. Do NOT give prasugrel to stroke/TIA patients - increased bleeding risk 1

5. Do NOT give routine upstream GP IIb/IIIa inhibitors in STEMI - no benefit, increased bleeding 2