Preparation for Coronary Angiography (CAG)
For elective coronary angiography in stable ischemic heart disease, do not routinely pretreat with P2Y12 inhibitors before the procedure; instead, administer aspirin if not already on chronic therapy, and give clopidogrel 600 mg loading dose in the catheterization laboratory only if PCI is performed. 1
Antiplatelet Therapy Preparation
For Stable Ischemic Heart Disease (Elective CAG)
- Continue chronic aspirin therapy if the patient is already taking it 1
- If not on chronic aspirin, administer an oral loading dose before the procedure 1
- Do not routinely pretreat with P2Y12 inhibitors (clopidogrel, ticagrelor, or prasugrel) before elective coronary angiography 1
- If PCI is performed, administer clopidogrel 600 mg loading dose in the cardiac catheterization laboratory 1
For NSTEACS (Non-ST Elevation Acute Coronary Syndrome)
The approach depends on timing to procedure:
- If CAG expected ≤24 hours after admission: Do not routinely pretreat with P2Y12 inhibitors 1
- If CAG expected >24 hours after admission: Consider pretreatment with P2Y12 inhibitors 1
- Continue aspirin in all cases 2
Critical caveat: If high suspicion exists for coronary anatomy requiring CABG, it is reasonable to avoid P2Y12 inhibitor pretreatment even if the procedure is delayed >24 hours, to avoid bleeding complications and surgical delays 1
Anticoagulation Management
If Patient Already on Anticoagulation for ACS
- Continue unfractionated heparin (UFH) through the procedure 2
- Enoxaparin: Continue for duration of hospitalization up to 8 days 2
- Fondaparinux: Continue for duration of hospitalization up to 8 days 2
- GP IIb/IIIa inhibitors: Can be continued if already started 2
Fasting Requirements
A 2-hour fasting period for liquids and solids is sufficient and improves patient satisfaction without increasing complications, challenging the traditional 6-hour fasting recommendation. 3
- Traditional guidelines recommend 6 hours fasting for solids and 2 hours for liquids (similar to general anesthesia protocols) 3
- Recent evidence from the CORO-NF randomized trial demonstrated:
Pre-Procedure Planning for Potential CABG
If CABG May Be Required Post-Angiography
Medication timing is critical to minimize bleeding risk while maintaining ischemic protection:
- Clopidogrel: Discontinue 5-7 days before elective CABG 2
- Prasugrel: Discontinue at least 7 days before CABG 2
- Aspirin: Continue through CABG 2
- GP IIb/IIIa inhibitors (eptifibatide or tirofiban): Discontinue 4 hours before CABG 2
- Enoxaparin: Discontinue 12-24 hours before CABG and transition to UFH 2
- Fondaparinux: Discontinue 24 hours before CABG and transition to UFH 2
- Bivalirudin: Discontinue 3 hours before CABG and transition to UFH 2
Important consideration: More urgent surgery may be performed by experienced surgeons if the incremental bleeding risk is considered acceptable, without waiting for full antiplatelet washout 2
Patient Education
- Provide structured patient education about the procedure to improve knowledge and reduce anxiety 4
- A 3-minute animated video shown on a tablet significantly improved knowledge scores and reduced anxiety scores (p<0.001) 4
- This benefit was observed even in patients who had previously undergone similar procedures 4
Key Clinical Pitfalls to Avoid
Do not reflexively pretreat all patients with P2Y12 inhibitors before diagnostic angiography—this increases bleeding without reducing ischemic events in stable patients 1
Avoid P2Y12 inhibitor pretreatment in ACS patients with high likelihood of CABG anatomy (e.g., known left main disease, severe triple vessel disease) to prevent surgical delays and bleeding complications 1
Do not use ticagrelor or prasugrel for elective PCI—clopidogrel is the preferred P2Y12 inhibitor with the most evidence and favorable bleeding profile 1
Remember that absence of significant stenosis on angiography does not exclude acute coronary syndrome—consider alternative diagnoses but maintain clinical vigilance 5