What are the contraindications to anticoagulation?

Contraindications to Anticoagulation

Anticoagulation is absolutely contraindicated in patients with active major bleeding, recent central nervous system hemorrhage, intracranial or spinal lesions at high risk for bleeding, recent spinal anesthesia/lumbar puncture, and severe thrombocytopenia (platelets <50,000/mcL). 1, 2

Absolute Contraindications

These conditions prohibit anticoagulation in all clinical situations:

• Active major bleeding requiring >2 units of blood transfusions in 24 hours 1
• Recent intracranial hemorrhage or central nervous system bleeding 1, 2
• Intracranial or spinal lesions at high risk for bleeding 1
• Recent spinal anesthesia or lumbar puncture due to risk of spinal/epidural hematoma resulting in long-term paralysis 1
• Severe thrombocytopenia with platelet count <50,000/mcL 1
• Severe bleeding diathesis or hemorrhagic coagulopathy 1
• Pregnancy (specifically for warfarin due to teratogenicity causing nasal hypoplasia, CNS abnormalities, and fetal hemorrhage) 2
• Active pathological bleeding (FDA contraindication for direct oral anticoagulants) 3

High-Risk Surgical Situations

• Recent, planned, or emergent surgery with high bleeding risk 1
• Recent or contemplated surgery of the central nervous system or eye 2
• Traumatic surgery resulting in large open surfaces 2

Specific Bleeding Sites

• Active bleeding from gastrointestinal, genitourinary, or respiratory tracts 2
• Cerebrovascular hemorrhage 2
• Aneurysms (cerebral or dissecting aorta) 2
• Pericarditis and pericardial effusions 2
• Bacterial endocarditis 2

Relative Contraindications

These require individualized risk-benefit assessment on a case-by-case basis:

• Chronic clinically significant bleeding lasting >48 hours 1
• Recurrent but inactive gastrointestinal bleeding 1
• Recent major surgery with intermediate bleeding risk 1
• High risk for falls and/or head trauma 1
• Moderate thrombocytopenia (platelets 50,000-150,000/mcL) 1
• Severe platelet dysfunction from uremia, medications, or dysplastic hematopoiesis 1
• Major trauma including cardiopulmonary resuscitation 1
• Aortic dissection 1
• Intracranial or spinal tumor 1
• Malignant hypertension 2
• Threatened abortion, eclampsia, and preeclampsia 2

Patient-Specific Risk Factors

• Elderly patients at increased risk of bleeding complications 1
• Patients unable to reliably comply with pharmacologic anticoagulation regimens 1
• Unsupervised patients with senility, alcoholism, psychosis, or other lack of cooperation 2

Important Clinical Caveats

Situations NOT Considered Contraindications

• Prolonged aPTT in patients with lupus anticoagulant or antiphospholipid syndrome is NOT a contraindication; these patients should be considered for indefinite anticoagulation after thrombotic events 1
• Peptic ulcer disease without active bleeding is not an absolute contraindication 1
• History of guaiac-positive stools alone is not an absolute contraindication 1

Timing Considerations for Resumption

• Trauma and neurosurgical patients: Anticoagulation is generally safe after the first or second postoperative week 1
• Stroke patients without intracranial hemorrhage: Can typically be anticoagulated 1
• Spinal cord injuries without hematomyelia: May be considered for anticoagulation 1

Critical Management Principle

Frequent reevaluation of contraindications and risk-benefit assessment is essential, particularly in cancer patients at increased bleeding risk, to facilitate implementation of anticoagulation when it becomes clinically prudent 1

Special Warnings

All low-molecular-weight heparins and fondaparinux carry FDA boxed warnings regarding spinal/epidural hematoma risk when administered to patients receiving neuraxial anesthesia or undergoing spinal puncture 1