How should antiplatelet (e.g. aspirin, clopidogrel) and anticoagulant (e.g. warfarin) therapy be managed in patients undergoing procedures?

Management of Antiplatelet and Anticoagulant Therapy in Patients Undergoing Procedures

For patients on antiplatelet or anticoagulant therapy undergoing elective procedures, aspirin should generally be continued perioperatively while P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel) must be discontinued 5-7 days before moderate-to-high bleeding risk procedures, and warfarin should be stopped 5 days prior with bridging reserved only for high thrombotic risk patients. 1

Risk Stratification Framework

Procedure Bleeding Risk Classification

Low bleeding risk procedures where anticoagulation/antiplatelet therapy can typically continue include:

• Diagnostic angiography without intervention 2
• Superficial peripheral nerve blocks (femoral, axillary plexus, popliteal sciatic) 1
• Dental procedures with local hemostatic measures 2

Moderate-to-high bleeding risk procedures requiring medication adjustment include:

• Percutaneous coronary intervention with stenting 1
• Coronary artery bypass grafting 1
• Intracranial neurosurgery 1
• Deep nerve blocks without compressibility 1

Patient Thrombotic Risk Assessment

High thrombotic risk patients (requiring careful consideration before stopping therapy):

• Recent acute coronary syndrome (within 6 months) 1
• Coronary stent placement within 1 month (any type) 1
• Coronary stent placement within 6 months if high thrombotic risk stent 1
• Mechanical heart valves 3
• Atrial fibrillation with high stroke risk 1

Lower thrombotic risk patients:

• Remote myocardial infarction (>12 months) 1
• Stable coronary artery disease without recent events 1
• Primary cardiovascular prevention 1

Antiplatelet Management by Drug

Aspirin Management

Continue aspirin perioperatively for most procedures. 1 The evidence shows aspirin continuation reduces thrombotic events without significantly increasing bleeding in most surgical contexts.

Discontinuation timing when required:

• Standard procedures: Stop 3 days before (last dose on D-3) 1
• Intracranial neurosurgery: Stop 5 days before (last dose on D-5) 1

Resume aspirin as early as possible postoperatively, ideally same day if hemostasis adequate. 1

P2Y12 Inhibitor Management (Clopidogrel, Ticagrelor, Prasugrel)

Discontinuation timing for moderate-to-high bleeding risk procedures:

• Clopidogrel: Stop 5 days before procedure (last dose on D-5) 1, 4
• Ticagrelor: Stop 5 days before procedure (last dose on D-5) 1
• Prasugrel: Stop 7 days before procedure (last dose on D-7) 1

For intracranial neurosurgery (higher bleeding risk):

• Clopidogrel: Stop 7 days before (last dose on D-7) 1
• Ticagrelor: Stop 7 days before (last dose on D-7) 1
• Prasugrel: Stop 9 days before (last dose on D-9) 1

Resume P2Y12 inhibitors within 24-72 hours postoperatively given the increased thrombotic risk during interruption. 1 Use the same P2Y12 inhibitor as preoperatively without a loading dose in most cases. 1

Critical Caveat for Recent Stent Patients

For patients within 1 month of stent placement requiring urgent non-cardiac surgery:

• Postpone procedure beyond 1 month if possible 1
• If surgery cannot be delayed, perform only in hospitals with 24/7 catheterization laboratory availability 1
• Consider bridging with IV antiplatelet agents (tirofiban or cangrelor) in ICU setting after multidisciplinary discussion 1

For patients within 6 months of myocardial infarction or high-risk stent:

• Postpone elective procedures up to 6 months when feasible 1

Anticoagulant Management

Warfarin Management

Discontinue warfarin 5 days before moderate-to-high bleeding risk procedures to allow INR to normalize. 3

Bridging anticoagulation strategy:

• Reserve bridging only for high thrombotic risk patients (mechanical heart valves, recent VTE within 3 months, high-risk atrial fibrillation) 5
• Use low molecular weight heparin (LMWH) or unfractionated heparin during warfarin interruption 5
• Stop LMWH 24 hours before procedure 6
• Do not bridge low-to-moderate thrombotic risk patients as bridging increases bleeding without clear benefit 5

Resume warfarin evening of procedure or next day once adequate hemostasis achieved. 3

Direct Oral Anticoagulants (DOACs)

Discontinuation timing based on renal function and bleeding risk:

• For normal renal function and moderate bleeding risk procedures: Stop 2-3 days before 1
• For impaired renal function or high bleeding risk: Extend discontinuation to 4-5 days 1
• Bridging is NOT recommended for DOACs due to their rapid onset/offset 1

Resume DOACs 24-72 hours postoperatively depending on bleeding risk and hemostasis adequacy. 1

Special Scenario: Dual Antiplatelet Therapy (DAPT)

Timing Considerations for Elective Procedures

Complete the full course of DAPT before elective procedures when possible:

• Bare-metal stent: Complete 1 month of DAPT 1
• Drug-eluting stent: Complete 3-6 months of DAPT (minimum) 1
• Acute coronary syndrome: Complete 12 months of DAPT 1

If procedure cannot be postponed:

• Continue aspirin perioperatively 1
• Discontinue P2Y12 inhibitor per timing above 1
• Never discontinue both agents simultaneously within 1 month of stent placement 1

Multidisciplinary Coordination

Discuss preoperative management with patient's cardiologist for procedures with intermediate-to-high bleeding risk in DAPT patients. 1 Document this discussion in the medical record.

Triple Therapy (Warfarin + DAPT)

Indications and Duration

For anterior MI with LV thrombus and bare-metal stent:

• Triple therapy (warfarin INR 2.0-3.0 + aspirin 75-100 mg + clopidogrel 75 mg) for 1 month 1
• Then warfarin + single antiplatelet for months 2-3 1
• Then DAPT alone for remainder of 12 months 1

For anterior MI with LV thrombus and drug-eluting stent:

• Triple therapy for 3-6 months 1
• Then DAPT alone for remainder of 12 months 1

For atrial fibrillation with acute coronary syndrome:

• Triple therapy should not exceed 30 days in most patients 1
• Transition to DOAC (preferred over warfarin) + clopidogrel 1
• Aspirin dose should not exceed 100 mg during triple therapy 1

Critical Bleeding Risk with Triple Therapy

Triple therapy carries approximately 7% major bleeding risk and 15% minor bleeding risk. 7 This significantly exceeds dual antiplatelet therapy alone (0% major bleeding in comparative studies). 7

Mandatory bleeding prophylaxis:

• Initiate proton pump inhibitor prophylactically in all patients on triple therapy 1, 2
• Avoid omeprazole and esomeprazole specifically due to CYP2C19 inhibition reducing clopidogrel efficacy 1, 4
• Use alternative PPIs (pantoprazole, lansoprazole, rabeprazole) 4

Regional Anesthesia Considerations

Neuraxial Anesthesia (Epidural/Spinal)

Timing for epidural catheter placement:

• Aspirin alone: Can proceed with neuraxial anesthesia 1
• Clopidogrel: Discontinue 5 days before catheter placement 1
• Ticagrelor: Discontinue 5 days before catheter placement 1
• Prasugrel: Discontinue 7 days before catheter placement 1

Catheter removal follows same timing rules as insertion. 1 Manipulation and removal carry identical bleeding risk to initial placement.

Do not compromise postoperative resumption of P2Y12 inhibitors due to epidural catheter presence. 1 Remove catheter early if needed to allow timely antiplatelet resumption.

Peripheral Nerve Blocks

Low bleeding risk blocks (superficial, compressible) can be performed with aspirin continuation. 1 Consider risk-benefit for P2Y12 inhibitors.

High bleeding risk blocks (deep, non-compressible) require P2Y12 inhibitor discontinuation per standard timing. 1

Perioperative Medication Restrictions

Avoid NSAIDs perioperatively in patients on DAPT as they significantly increase bleeding risk. 1 COX-2 inhibitors (coxibs) may be used as alternative. 1

Never bridge antiplatelet agents with heparin or LMWH as this increases bleeding without proven benefit. 1

Emergency Surgery in Anticoagulated Patients

For life-threatening bleeding with warfarin (INR >2.5):

• Administer 4-factor prothrombin complex concentrate plus low-dose vitamin K 8
• Vitamin K subcutaneously only in urgent/emergency surgery 3

For urgent cardiac surgery on multiple antiplatelet agents:

• Delay surgery 12 hours if patient received abciximab when feasible 9
• Consider prophylactic aprotinin, aminocaproic acid, or tranexamic acid 9
• Platelet transfusions may be less effective within 4 hours of clopidogrel loading dose or 2 hours of maintenance dose 4

Monitoring for Epidural Hematoma

Clinical presentation: Severe pain at injection site with rapid neurological deterioration 6

Diagnosis: MRI imaging 6

Treatment: Urgent surgical decompression with progressive neurological dysfunction to prevent permanent sequelae 6

Risk factors for epidural hematoma:

• Spinal stenosis or ankylosing spondylitis 6
• High-risk procedures combined with anatomic risk factors 6
• Bleeding observed during procedure 6
• Multiple needle attempts 6