Transitioning from Continuous Heparin to Apixaban After Popliteal Artery Thrombectomy
Stop the heparin infusion and start apixaban 10 mg orally twice daily immediately once adequate hemostasis is confirmed, without any bridging period. 1
Timing of Heparin Discontinuation and Apixaban Initiation
Discontinue unfractionated heparin (UFH) when adequate surgical hemostasis is established, typically at least 6–24 hours post-thrombectomy, depending on bleeding risk assessment. 2
Begin apixaban at the time the next heparin dose would have been given—there is no need for overlap or bridging anticoagulation when transitioning from parenteral UFH to apixaban. 1
Apixaban's rapid onset of action (peak effect within 3–4 hours) eliminates the need for continued heparin coverage during the transition. 2, 1
Apixaban Dosing Regimen for Acute Arterial Thrombosis
Start with 10 mg orally twice daily for the first 7 days, then reduce to 5 mg twice daily for long-term therapy. 1
This loading-dose regimen mirrors the FDA-approved protocol for acute venous thromboembolism and is appropriate for acute arterial thrombosis requiring therapeutic anticoagulation. 2, 1
Do not use the 2.5 mg twice-daily dose in this acute setting; that lower dose is reserved only for extended secondary prevention after completing at least 6 months of full-dose anticoagulation. 1
Renal Function Considerations
Apixaban is safe and requires no dose adjustment when creatinine clearance is ≥30 mL/min, which applies to your hemodynamically stable patient. 2, 1
If creatinine clearance is 15–29 mL/min, apixaban can still be used but with caution; the FDA label does not mandate dose reduction, though some guidelines suggest considering 2.5 mg twice daily in this range for atrial fibrillation (not acute thrombosis). 1
Apixaban is contraindicated if creatinine clearance is <15 mL/min or the patient is on dialysis. 1
Unlike low-molecular-weight heparin (LMWH), apixaban does not accumulate significantly in moderate renal impairment, making it preferable to LMWH in patients with CrCl 30–60 mL/min. 3, 4
Why Bridging Is Not Recommended
Routine bridging with LMWH or continued UFH during the transition to apixaban increases major bleeding risk three-fold (4.8% vs 1.6%) without reducing thrombotic events. 2, 5, 6
The rapid pharmacokinetic profile of apixaban (half-life 12 hours, peak effect 3–4 hours) obviates the need for overlapping parenteral anticoagulation. 5, 1
Bridging should only be considered in patients at very high thrombotic risk (e.g., recent pulmonary embolism or deep vein thrombosis within ≤3 months), which does not apply to most post-thrombectomy patients. 5
Monitoring and Follow-Up
No routine laboratory monitoring of apixaban levels or coagulation parameters (INR, aPTT) is required, as these tests do not reliably reflect apixaban's anticoagulant effect. 2, 5, 1
Reassess renal function within 48–72 hours post-operatively, as acute kidney injury can prolong apixaban elimination and increase bleeding risk. 5, 1
Confirm adequate hemostasis before initiating apixaban; if active bleeding persists or surgical contraindications exist, delay apixaban and provide mechanical or pharmacologic venous thromboprophylaxis (e.g., sequential compression devices or prophylactic LMWH). 2, 5
Common Pitfalls to Avoid
Do not continue heparin for 24–48 hours "to be safe"—this unnecessary overlap dramatically increases bleeding without added thrombotic benefit. 2, 5
Do not start with the 2.5 mg twice-daily dose in the acute phase; this subtherapeutic dose is only for extended secondary prevention after completing initial treatment. 1
Do not use INR or aPTT to guide the transition—apixaban affects these tests unpredictably and they should not be used to time the switch from heparin. 2, 5, 1
Do not initiate apixaban if an epidural catheter is in place; wait until the catheter is removed and at least 6 hours have elapsed. 5
Do not forget to reassess renal function post-operatively—acute changes in creatinine clearance can alter apixaban clearance and bleeding risk. 5, 1