What is the best anticoagulation strategy for a patient with atrial fibrillation (AFib) and impaired renal function (chronic kidney disease, CKD) who develops a new thrombus despite being on Eliquis (apixaban) 5mg twice daily (bid)?

From the Guidelines

For a patient with atrial fibrillation and chronic kidney disease who develops a new thrombus despite being on apixaban 5mg twice daily, the recommended approach is to switch to warfarin with a target INR of 2.0-3.0, as the development of a thrombus while on a direct oral anticoagulant (DOAC) like apixaban represents treatment failure. This change is necessary because the patient has failed DOAC therapy, and warfarin works through a different anticoagulation mechanism, potentially overcoming resistance 1. The decision to switch to warfarin is based on the most recent guidelines, which recommend the use of warfarin in patients who have failed DOAC therapy, especially in those with high-risk features such as chronic kidney disease 1. Key considerations in this approach include:

• Initiating warfarin with a bridging period using low molecular weight heparin (such as enoxaparin) or unfractionated heparin until the INR reaches the therapeutic range 1
• Adjusting the dose of enoxaparin based on the patient's renal function, typically reducing to 1mg/kg once daily if creatinine clearance is below 30 ml/min 1
• Regular INR monitoring, initially twice weekly until stable, then monthly, to ensure that the patient remains within the therapeutic range 1
• Monitoring renal function regularly, as worsening CKD may require further dose adjustments 1 It's also important to note that the use of NOACs, including apixaban, is generally not recommended in patients with end-stage renal disease (CrCl < 15 mL/min or dialysis-dependent), and that warfarin is preferred in these cases 1. Overall, the switch to warfarin is justified because it allows for monitoring of anticoagulation adequacy through INR testing, which is particularly valuable in patients who have failed DOAC therapy, and has more extensive clinical experience in high-risk patients 1.

From the FDA Drug Label

The recommended dose of apixaban tablets for most patients is 5 mg taken orally twice daily. The recommended dose of apixaban tablets is 2.5 mg twice daily in patients with at least two of the following characteristics: • age greater than or equal to 80 years • body weight less than or equal to 60 kg • serum creatinine greater than or equal to 1.5 mg/dL Treatment of DVT and PE The recommended dose of apixaban tablets is 10 mg taken orally twice daily for the first 7 days of therapy. After 7 days, the recommended dose is 5 mg taken orally twice daily.

The patient is already taking Eliquis (apixaban) 5mg twice daily for AFib, but has developed a new thrombus. Given the patient's chronic kidney disease (CKD), the dose of apixaban should be considered for adjustment.

• The patient's current dose is 5mg twice daily, but the label recommends a dose reduction to 2.5mg twice daily if the patient has at least two of the following characteristics: age ≥ 80 years, body weight ≤ 60 kg, or serum creatinine ≥ 1.5 mg/dL.
• However, for the treatment of DVT and PE, the recommended dose is 10mg twice daily for the first 7 days, followed by 5mg twice daily. Since the patient has a new thrombus, the dose of apixaban may need to be increased to 10mg twice daily for the first 7 days, but this is not explicitly stated for a patient with AFib and CKD who develops a new thrombus while on apixaban 5mg twice daily. Discontinuing apixaban and starting Lovenox may be considered, but the label does not provide direct guidance on this specific scenario 2. It is essential to weigh the risks and benefits of anticoagulation in this patient, considering the presence of CKD and the development of a new thrombus despite being on apixaban. The decision to discontinue apixaban and start Lovenox should be made on a case-by-case basis, taking into account the individual patient's characteristics and clinical presentation.

From the Research

Anticoagulation Strategy for Patient with Atrial Fibrillation and Chronic Kidney Disease

The patient in question has atrial fibrillation (AFib) and is currently taking Eliquis (apixaban) 5mg twice daily, but has developed a new partially occluded thrombus in the proximal superficial femoral vein. Considering the patient's chronic kidney disease (CKD), the best anticoagulation strategy must be determined.

Current Anticoagulation Therapy

• The patient is currently on apixaban 5mg bid, which is a common treatment for AFib and venous thromboembolism (VTE) 3, 4.
• Apixaban has been shown to be effective in reducing the risk of recurrent VTE without increasing the risk of major bleeding 3.

Considerations for Chronic Kidney Disease

• Patients with CKD, especially those with stage 5 CKD or end-stage kidney disease (ESKD), may require adjusted anticoagulation therapy 5.
• Apixaban has been compared to warfarin in patients with CKD and found to have advantages in terms of effectiveness and bleeding safety 5.

Management of New Thrombus

• The development of a new thrombus despite anticoagulation therapy may require re-evaluation of the patient's treatment plan.
• Options may include continuing apixaban, switching to a different anticoagulant such as low-molecular-weight heparin (e.g. Lovenox), or adding an additional anticoagulant 4, 6.
• However, there is limited evidence to support switching from apixaban to Lovenox in this scenario, and apixaban may still be an effective option for this patient 3, 5.

Key Points to Consider

• The patient's CKD and new thrombus development require careful consideration of the anticoagulation strategy.
• Apixaban may still be an effective option for this patient, but close monitoring of the patient's condition and adjustment of the treatment plan as needed is crucial 3, 4, 5.
• Further studies are needed to determine the optimal anticoagulation strategy for patients with CKD and AFib who develop new thrombi 4, 5.