Can a 24-year-old female patient with peripartum cardiomyopathy, organized left ventricle (LV) and right ventricle (RV) clots, and an extensive left upper limb deep vein thrombosis (DVT) be switched from enoxaparin (low molecular weight heparin) to rivaroxaban (factor Xa inhibitor)?

Management of Anticoagulation in Peripartum Cardiomyopathy with Ventricular Clots and DVT

Rivaroxaban should not be used in this 24-year-old female with peripartum cardiomyopathy, organized LV and RV clots, and extensive left upper limb DVT who is currently on enoxaparin. 1, 2

Rationale for Recommendation

Contraindication for Rivaroxaban in Peripartum Cardiomyopathy

• Rivaroxaban is explicitly contraindicated in peripartum cardiomyopathy patients according to European Society of Cardiology guidelines 1
• The drug label states that rivaroxaban crosses the placental barrier and has not been evaluated in pregnancy 2
• Even in the postpartum period, there is insufficient evidence supporting the safety and efficacy of rivaroxaban in patients with peripartum cardiomyopathy

High Thromboembolic Risk in This Patient

This patient has multiple high-risk features that warrant careful anticoagulation management:

• Peripartum cardiomyopathy with organized LV and RV clots
• Extensive left upper limb DVT
• Recent postpartum status (within weeks of delivery)

Recommended Anticoagulation Approach

Continue LMWH (Enoxaparin)

• LMWH has become the drug of choice for treatment of VTE in pregnancy and puerperium 1
• For peripartum cardiomyopathy with LVEF <30%, anticoagulation is reasonable at diagnosis until 6-8 weeks postpartum 1
• The recommended therapeutic dose should be calculated based on body weight:
  • Enoxaparin 1 mg/kg body weight twice daily
  • Target 4-6 hour peak anti-Xa values of 0.6-1.2 IU/mL 1

Transition to Vitamin K Antagonist (Warfarin)

• After the initial postpartum period (6-8 weeks), transition to warfarin is appropriate
• Vitamin K antagonists do not enter breast milk in active forms and are safe for nursing mothers 1
• Target INR should be between 2-3 with regular monitoring every 1-2 weeks 1

Duration of Anticoagulation

• For patients with peripartum cardiomyopathy and intracardiac thrombi, anticoagulation should be continued until:
  • Complete resolution of ventricular thrombi on imaging
  • Significant improvement in cardiac function (LVEF >35%)
  • At least 3-6 months of therapy has been completed 1, 3

Monitoring Recommendations

• Regular echocardiographic assessment to monitor:
  • Resolution of ventricular thrombi
  • Improvement in cardiac function
• Anti-Xa monitoring for LMWH therapy to ensure therapeutic levels
• Regular assessment of bleeding risk

Pitfalls to Avoid

1. Premature discontinuation of anticoagulation: Patients with peripartum cardiomyopathy have a high risk of recurrent thromboembolism 4, 5
2. Inadequate anticoagulation intensity: Cases of recurrent thromboembolism have been reported even with therapeutic anticoagulation 4
3. Switching to NOACs without evidence: Despite convenience, NOACs like rivaroxaban lack evidence in peripartum cardiomyopathy patients with ventricular thrombi 1, 2
4. Ignoring the need for close monitoring: Regular assessment of both thromboembolic and bleeding risks is essential

Special Considerations

• If the patient has severe protein C or protein S deficiencies (which can occur in peripartum states), this further increases thromboembolic risk 4
• Bromocriptine, sometimes used in peripartum cardiomyopathy management, should be accompanied by prophylactic or therapeutic anticoagulation due to potential association with thromboembolic events 1

In conclusion, this patient should continue enoxaparin therapy with eventual transition to warfarin rather than switching to rivaroxaban, given the high-risk features and lack of evidence supporting NOACs in peripartum cardiomyopathy with ventricular thrombi.