Do you discontinue antiplatelet (anti-platelet) therapy when initiating anticoagulation (blood thinner) therapy?

Antiplatelet Therapy Should Be Discontinued When Starting Anticoagulation in Most Clinical Scenarios

In most clinical scenarios, antiplatelet therapy should be discontinued when initiating anticoagulation therapy, unless there is a specific indication for dual therapy such as recent coronary stenting or high thrombotic risk. 1

Decision Algorithm for Managing Antiplatelet Therapy When Starting Anticoagulation

1. Patients with Atrial Fibrillation (AF)

• For patients with new-onset AF requiring anticoagulation who are already on aspirin for acute coronary syndrome (ACS): Discontinue aspirin after anticoagulation is initiated 1
• For patients with stable coronary artery disease: Antiplatelet medications should be stopped no later than 12 months after the last percutaneous coronary intervention (PCI) 1

2. Patients with Recent Coronary Stenting

• If stent placed within 1-3 months: Continue P2Y12 inhibitor (preferably clopidogrel) and start anticoagulation, but discontinue aspirin 1
• If stent placed 3-6 months ago: Continue single antiplatelet therapy (SAPT) with either clopidogrel or aspirin plus anticoagulation 1
• If stent placed >6-12 months ago: Consider discontinuing antiplatelet therapy, especially in patients at high bleeding risk 1

3. Patients with Peripheral Artery Disease (PAD)

• For PAD without intervention or with surgical repair: Stop all antiplatelet therapy and treat with anticoagulation alone 1
• For PAD with recent endovascular intervention/stenting (within 1-3 months): Continue SAPT (preferably clopidogrel) with anticoagulation 1
• If >3 months post-endovascular intervention: All antiplatelet therapy may be stopped and most patients can be treated with anticoagulation alone 1

4. Patients with Prior Stroke/TIA

• For patients on antiplatelet therapy for prior TIA or stroke who develop venous thromboembolism (VTE): Stop all antiplatelet therapy and treat with anticoagulation alone (preferably DOAC) 1

Important Considerations for Specific Scenarios

Triple Therapy (Dual Antiplatelet + Anticoagulation)

• Triple therapy significantly increases bleeding risk without providing additional protection against thrombotic events in most cases 1
• Should be limited to patients at highest risk for thrombotic complications and ideally not exceed 30 days 1
• When triple therapy is necessary, aspirin dose should not exceed 100 mg 1

Bleeding Risk Management

• For patients on ≥2 antithrombotic agents, start or continue a proton pump inhibitor to reduce GI bleeding risk 1
• For patients on warfarin plus antiplatelet therapy, aim for the lower end of the target INR range (2.0-2.5) with more frequent monitoring 1
• DOACs are preferred over warfarin when combining with antiplatelet therapy due to lower bleeding risk 1

Duration of Combined Therapy

• The shortest possible duration of combined therapy should be used based on thrombotic and bleeding risk assessment
• Registry data shows continuing antiplatelet therapy beyond 1 year in patients on anticoagulation increases bleeding complications without offering further ischemic protection 1

Common Pitfalls to Avoid

1. Continuing antiplatelet therapy indefinitely: Many patients may be continued on long-term combination therapies that provide little additional benefit while carrying significant bleeding risk 2

2. Overlooking the indication for antiplatelet therapy: Carefully assess if the original indication for antiplatelet therapy still requires treatment when anticoagulation is initiated

3. Failing to reassess therapy regularly: The need for combination therapy should be reassessed periodically, especially after the high-risk period for thrombotic events has passed

4. Not considering patient-specific bleeding risk factors: Age >75 years, prior bleeding history, renal impairment, and concomitant use of NSAIDs all increase bleeding risk with combination therapy

In conclusion, while specific clinical scenarios may warrant temporary combined antiplatelet and anticoagulant therapy, the general approach should be to discontinue antiplatelet therapy when initiating anticoagulation unless there is a compelling reason to maintain both treatments.