Antiplatelet Therapy for Patients Undergoing Angiography
For patients undergoing diagnostic angiography alone without intervention, continue single antiplatelet therapy (aspirin 75-100 mg daily) if already on it for established coronary disease, or no antiplatelet therapy if this is initial diagnostic evaluation. 1, 2
Diagnostic Angiography Without Intervention
No antiplatelet therapy is required for patients undergoing diagnostic angiography who have no established coronary artery disease and are not proceeding to percutaneous coronary intervention (PCI). 2
Continue existing single antiplatelet therapy (aspirin 75-100 mg daily OR clopidogrel 75 mg daily) in patients with established coronary artery disease undergoing diagnostic angiography. 1, 2
If Angiography Proceeds to PCI with Stenting
The antiplatelet strategy changes dramatically based on clinical presentation and stent type:
For Acute Coronary Syndrome (ACS) with PCI:
Initiate dual antiplatelet therapy (DAPT) immediately with a loading dose of aspirin 160-325 mg plus either ticagrelor 180 mg or prasugrel 60 mg (preferred over clopidogrel 600 mg). 1, 3
Ticagrelor or prasugrel is strongly preferred over clopidogrel in ACS patients undergoing PCI to reduce major adverse cardiovascular events. 1, 4
Maintenance regimen: Ticagrelor 90 mg twice daily (preferred) or clopidogrel 75 mg daily, plus aspirin 75-100 mg daily for 12 months minimum. 1, 3, 2
For Elective PCI with Drug-Eluting Stent (DES):
First 3-6 months: Aspirin 75-325 mg daily plus clopidogrel 75 mg daily (minimum duration varies: 3 months for -limus stents, 6 months for -taxel stents). 1, 3
Months 3/6-12: Continue DAPT with low-dose aspirin 75-100 mg daily plus clopidogrel 75 mg daily. 1, 3
After 12 months: Transition to single antiplatelet therapy (aspirin 75-100 mg daily OR clopidogrel 75 mg daily) indefinitely. 1, 3, 2
For Elective PCI with Bare-Metal Stent (BMS):
First month: Aspirin 75-325 mg daily plus clopidogrel 75 mg daily. 1, 3, 2
Months 2-12: Continue DAPT with low-dose aspirin 75-100 mg daily plus clopidogrel 75 mg daily. 1, 2
After 12 months: Transition to single antiplatelet therapy. 1, 2
For PCI Without Stent Placement (Balloon Angioplasty Only):
First month only: Aspirin 75-325 mg daily plus clopidogrel 75 mg daily. 1
After 1 month: Transition to single antiplatelet therapy. 1
Critical Bleeding Risk Mitigation Strategies
Add a proton pump inhibitor (PPI) to all patients on DAPT to reduce gastrointestinal bleeding risk. 1, 3, 4
Use radial artery access (not femoral) during PCI to reduce bleeding, vascular complications, and mortality. 1
Keep aspirin dose at 75-100 mg daily during maintenance phase (after initial loading) to minimize bleeding while maintaining efficacy. 1, 3, 4
Consider shorter DAPT duration (6 months or less) in patients with high bleeding risk (PRECISE-DAPT score ≥25), then transition to single antiplatelet therapy. 4, 2
Common Pitfalls to Avoid
Never discontinue DAPT prematurely within the first month after any stent placement—this dramatically increases risk of stent thrombosis, which carries 20-45% mortality. 1
Elective surgery must be postponed until completion of the minimum DAPT duration (1 month for BMS, 3-6 months for DES, ideally 12 months for all stents). 1, 3
If surgery cannot be deferred, continue aspirin if at all possible and restart the P2Y12 inhibitor (clopidogrel/ticagrelor) as soon as possible postoperatively—do NOT use "bridging" with warfarin or glycoprotein IIb/IIIa inhibitors as there is no evidence of benefit and increased bleeding risk. 1, 2
Avoid prasugrel in patients with prior stroke or TIA (contraindicated). 4
For dental procedures, there is no indication to interrupt antiplatelet therapy as bleeding risk is minimal with local hemostatic measures. 1
Special Consideration: Ticagrelor Monotherapy Strategy
In ACS patients who have tolerated DAPT with ticagrelor, transition to ticagrelor monotherapy (discontinue aspirin) ≥1 month after PCI is an alternative bleeding reduction strategy. 1
This represents the most recent guideline recommendation (2025) for reducing bleeding while maintaining thrombotic protection. 1