What is the optimal management strategy for a morbidly obese patient with pulmonary embolism (PE)?

From the Guidelines

Optimal Management Strategy for Morbidly Obese Patients with Pulmonary Embolism (PE) Morbidly obese patients with pulmonary embolism (PE) require a multidisciplinary approach, with anticoagulation therapy being the cornerstone of treatment 1.

Key Considerations

• Anticoagulation: Low molecular weight heparin (LMWH), such as enoxaparin 1.5 mg/kg actual body weight subcutaneously every 12 hours, or unfractionated heparin with a weight-based dosing regimen, is recommended 1.
• Thrombolytic Therapy: Alteplase 100 mg intravenously over 2 hours may be indicated in patients with massive PE and hemodynamic instability 1.
• Risk Assessment: Evaluation of the size and/or function of the right ventricle (RV) and laboratory biomarkers is essential in patients without haemodynamic instability 1.
• Reperfusion Options: Systemic thrombolysis, surgical embolectomy, or catheter-directed treatment should be considered in patients with high-risk PE, taking into account the resources and expertise available at the hospital 1.

Additional Considerations for Morbidly Obese Patients

• Cardiovascular Evaluation: A thorough cardiovascular evaluation is necessary to assess the presence and degree of cardiac pathology and dysfunction, which may be underestimated in obese patients 1.
• Surgical Risk: The risk of an adverse perioperative cardiac event is related to the degree of underlying coronary heart disease, associated comorbidities, and the type of surgery performed 1.
• Weight-Based Dosing: Weight-based dosing regimens should be used for anticoagulation therapy in morbidly obese patients to ensure adequate dosing 1.

From the FDA Drug Label

The efficacy data are provided in Table 13. Table 13. Efficacy of Fondaparinux Sodium in the Treatment of Pulmonary Embolism (All Randomized)

The primary efficacy endpoint was confirmed, symptomatic, recurrent VTE reported up to Day 97.

The optimal management strategy for a morbidly obese patient with pulmonary embolism (PE) is not directly addressed in the provided drug label.

• Key points:
  • The label discusses the treatment of PE with fondaparinux sodium, but does not provide specific guidance for morbidly obese patients.
  • The dosing of fondaparinux sodium is based on body weight, with doses of 5 mg, 7.5 mg, or 10 mg SC once daily for patients with body weights <50 kg, 50-100 kg, or >100 kg, respectively.
  • However, the label does not provide information on how to manage morbidly obese patients with PE, and the clinical trials described in the label excluded patients with certain comorbidities, but do not specifically address obesity. 2

From the Research

Optimal Management Strategy for Morbidly Obese Patients with Pulmonary Embolism (PE)

The management of morbidly obese patients with PE requires careful consideration of anticoagulation therapy.

• The choice of initial anticoagulation is important, with direct oral anticoagulants being the preferred choice 3.
• However, in special populations such as obese patients, vitamin K antagonists and low-molecular-weight heparin (LMWH) may be preferred 3.
• LMWH has been shown to be effective in treating PE in morbidly obese patients, with a weight-based dosing regimen up to 160 kg 4.
• In patients with a body mass index (BMI) ≥ 40 kg/m2, a reduced weight-based dose of enoxaparin 0.8 mg/kg twice daily may be considered 5.
• The use of a modified dosing weight for heparin therapy has also been reported to be successful in a morbidly obese patient 6.
• For patients with renal insufficiency and contrast allergy, the ventilation perfusion scan provides an alternative for diagnosis of PE 7.
• The initial therapy for patients with PE is anticoagulation, with the use of vasopressors, inotropes, pulmonary artery (PA) vasodilators, and mechanical ventilation to stabilize critically ill patients 7.
• Thrombolytic therapy may be considered in patients with massive PE, but the limited documented benefit must be weighed against the increased risk of life-threatening hemorrhage 7.

Anticoagulation Management

Anticoagulation management is crucial in the treatment of PE in morbidly obese patients.

• The use of LMWH, such as enoxaparin, dalteparin, and tinzaparin, has been shown to be effective in preventing recurrent PE 5.
• The dosage of anticoagulants in obesity has not been established for most anticoagulants, including LMWH, non-vitamin K antagonist oral anticoagulants (NOAC), and pentasaccharides (fondaparinux) 5.
• Rivaroxaban, apixaban, or dabigatran may be used as thromboprophylaxis in patients with BMI < 40 kg/m2, whereas rivaroxaban and apixaban may be administered to obese patients with VTE or AF, including BMI > 40 kg/m2, at standard fixed-dose 5.

Special Considerations

Special considerations must be taken into account when managing morbidly obese patients with PE.

• Morbid obesity is defined as a BMI higher than 40 kg/m2, and there are no evidence-based drug dosing strategies for these patients 4.
• The use of a modified dosing weight for heparin therapy may be necessary to avoid potentially supratherapeutic activated partial thromboplastin times (aPTTs) using actual body weight and subtherapeutic aPTTs using ideal body weight 6.
• Further investigation is necessary to determine the optimal dosing weight for unfractionated heparin in morbidly obese patients presenting with acute thrombosis 6.