What is the approach to initiating anticoagulation in a 68-year-old male with new onset atrial flutter, mild thrombocytopenia of unknown etiology, and newly diagnosed diabetes mellitus with an Hemoglobin A1c (HbA1c) level indicating poor glycemic control?

From the Guidelines

For a 68-year-old male with new onset atrial flutter, mild thrombocytopenia of unknown etiology, and newly diagnosed diabetes mellitus, anticoagulation should be initiated with a direct oral anticoagulant (DOAC) like apixaban 5mg twice daily, after careful assessment of stroke and bleeding risks, as recommended by the 2024 ESC guidelines for the management of atrial fibrillation 1.

Key Considerations

• The patient's age and newly diagnosed diabetes mellitus increase the risk of stroke, making anticoagulation crucial.
• Atrial flutter carries a similar stroke risk to atrial fibrillation, and the CHA2DS2-VA score can be used to assess thromboembolic risk, although a score of 2 or more is generally recommended as an indicator of elevated risk 1.
• Before starting anticoagulation, it is essential to investigate the cause of thrombocytopenia with a complete blood count, peripheral blood smear, and possibly bone marrow examination.
• Anticoagulation can generally be considered if the platelet count is >50,000/μL, but close monitoring is essential, with weekly platelet count checks recommended initially, and frequency adjusted based on stability.

Management of Diabetes

• The patient's diabetes should be addressed with metformin 500mg twice daily initially, along with lifestyle modifications and endocrinology referral for comprehensive diabetes management, as effective glycaemic control is recommended to reduce the burden, recurrence, and progression of atrial fibrillation 1.

Anticoagulation Therapy

• Direct oral anticoagulants (DOACs) are recommended for patients with atrial fibrillation at elevated thromboembolic risk, and apixaban 5mg twice daily is a suitable option, with dose reduction to 2.5mg twice daily if the patient has two or more of the following: age ≥80 years, weight ≤60kg, or serum creatinine ≥1.5mg/dL.
• Warfarin (target INR 2-3) remains an alternative if DOACs are contraindicated, but maintaining VKA treatment rather than switching to a DOAC may be considered in patients aged ≥75 years on clinically stable therapeutic VKA with polypharmacy to prevent excess bleeding risk 1.

Monitoring and Follow-up

• Individualized reassessment of thromboembolic risk is recommended at periodic intervals in patients with atrial fibrillation to ensure anticoagulation is started in appropriate patients 1.
• Close monitoring of the patient's platelet count and renal function is essential, with adjustments to anticoagulation therapy as needed.

From the FDA Drug Label

2.1 Recommended Dose Reduction of Risk of Stroke and Systemic Embolism in Patients with Nonvalvular Atrial Fibrillation The recommended dose of apixaban tablets for most patients is 5 mg taken orally twice daily.

The approach to initiating anticoagulation in a 68-year-old male with new onset atrial flutter, mild thrombocytopenia of unknown etiology, and newly diagnosed diabetes mellitus is not directly addressed in the provided drug label. However, for patients with nonvalvular atrial fibrillation, the recommended dose of apixaban is 5 mg taken orally twice daily. Atrial flutter is a type of arrhythmia similar to atrial fibrillation, but the label does not explicitly mention atrial flutter. Considering the patient's condition and the lack of direct information, a conservative clinical decision would be to consult the label's recommendations for nonvalvular atrial fibrillation, while also taking into account the patient's mild thrombocytopenia and poor glycemic control, which may increase the risk of bleeding. However, the label does not provide guidance on how to initiate anticoagulation in this specific scenario. 2

From the Research

Approach to Initiating Anticoagulation

The approach to initiating anticoagulation in a 68-year-old male with new onset atrial flutter, mild thrombocytopenia of unknown etiology, and newly diagnosed diabetes mellitus with an HbA1c level indicating poor glycemic control involves several considerations:

• The patient's atrial flutter increases the risk of thromboembolic events, and anticoagulation is recommended to reduce this risk 3, 4.
• The presence of mild thrombocytopenia may increase the risk of bleeding, but studies suggest that this may not have a significant impact on the risk of bleeding or thrombotic complications in patients with atrial fibrillation or flutter undergoing anticoagulation therapy 5.
• The patient's newly diagnosed diabetes mellitus with poor glycemic control increases the risk of thrombotic events, and anticoagulation may be beneficial in reducing this risk 3.
• The choice of anticoagulant should be based on the patient's individual risk factors, including the CHA2DS2-VASc score, and the presence of any contraindications to specific anticoagulants 3, 4.

Anticoagulation Options

The following anticoagulation options may be considered:

• Direct oral anticoagulants (DOACs) such as rivaroxaban, apixaban, or dabigatran, which have been shown to be effective in reducing the risk of thromboembolic events in patients with atrial fibrillation or flutter 6, 7.
• Warfarin, which has been traditionally used for anticoagulation in patients with atrial fibrillation or flutter, but requires regular monitoring of international normalized ratio (INR) levels 4.
• Aspirin, which may be considered in patients with a low risk of thromboembolic events or those with contraindications to anticoagulation therapy 4.

Considerations for Concomitant Aspirin Use

The use of concomitant aspirin with anticoagulation therapy should be carefully considered, as it may increase the risk of bleeding complications 6.

• The study by 6 found that the concomitant use of direct oral anticoagulants and aspirin was associated with an increased risk of major adverse cardiac events and bleeding complications compared to the use of direct oral anticoagulants alone.