What is the preferred anticoagulant, aspirin or Eliquis (Apixaban), for a 94-year-old patient with new onset Atrial Fibrillation (AF)?

From the Guidelines

Eliquis (Apixaban) is the preferred anticoagulant over aspirin for a 94-year-old patient with new onset Atrial Fibrillation (AF).

Reasons for Preference

• The 2021 ACC/AHA clinical performance and quality measures for adults with atrial fibrillation or atrial flutter recommend DOACs, such as apixaban, over warfarin in DOAC-eligible patients with AF, except with moderate or severe mitral stenosis or a mechanical heart valve 1.
• The ARISTOTLE trial showed that apixaban 5 mg twice daily reduced stroke or systemic embolism by 21% compared with warfarin, combined with a 31% reduction in major bleeding and an 11% reduction in all-cause mortality 1.
• Apixaban has also been compared with aspirin in AF patients and significantly reduced stroke or systemic embolism by 55% compared with aspirin, with no or only a small difference in rates of major bleeding or intracranial haemorrhage 1.
• The 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation recommends oral anticoagulants, including apixaban, for patients with AF and an elevated CHA2DS-VASc score of 2 or greater in men or 3 or greater in women 1.
• Key points from the 2012 focused update of the ESC guidelines for the management of atrial fibrillation suggest that the use of antiplatelet therapy, such as aspirin, for stroke prevention in AF should be limited to the few patients who refuse any form of OAC, and that NOACs, including apixaban, offer better efficacy, safety, and convenience compared with OAC with VKAs 1.

Important Considerations

• The patient's age and potential comorbidities should be taken into account when selecting an anticoagulant regimen, and the choice of anticoagulant should be based on the risk of thromboembolism, irrespective of whether the AF pattern is paroxysmal, persistent, or permanent 1.
• The CHA2DS2-VASc score is recommended for assessment of stroke risk in patients with AF, except with moderate or severe mitral stenosis or a mechanical heart valve 1.
• Regular review and reassessment of the need for and choice of anticoagulant therapy are recommended to reassess stroke and bleeding risks 1.

From the FDA Drug Label

In ARISTOTLE, patients were randomized to apixaban 5 mg orally twice daily (or 2. 5 mg twice daily in subjects with at least 2 of the following characteristics: age greater than or equal to 80 years, body weight less than or equal to 60 kg, or serum creatinine greater than or equal to 1.5 mg/dL) or to warfarin (targeted to an INR range of 2.0 to 3. 0) The primary objective of ARISTOTLE was to determine whether apixaban 5 mg twice daily (or 2. 5 mg twice daily) was effective (noninferior to warfarin) in reducing the risk of stroke (ischemic or hemorrhagic) and systemic embolism. Apixaban was superior to warfarin for the primary endpoint of reducing the risk of stroke and systemic embolism (Table 9 and Figure 4). Table 9: Key Efficacy Outcomes in Patients with Nonvalvular Atrial Fibrillation in ARISTOTLE (Intent-to-Treat Analysis) Apixaban N=9120 n (%/year) Warfarin N=9081 n (%/year) Hazard Ratio (95% CI)P-value Stroke or systemic embolism 212 (1.27) 265 (1.60) 0.79 (0.66,0.95) 0.01

For a 94-year-old patient with new onset Atrial Fibrillation (AF), the preferred anticoagulant is Eliquis (Apixaban).

• The ARISTOTLE study showed that apixaban was superior to warfarin in reducing the risk of stroke and systemic embolism.
• The study also found that apixaban had a lower rate of major bleeding compared to warfarin.
• The dosing for apixaban in this patient would be 2.5 mg twice daily, as they meet the criteria of being over 80 years old 2.
• Aspirin is not compared to apixaban in the provided study, therefore it is not possible to draw a conclusion about its effectiveness in comparison to apixaban for this patient.

From the Research

Anticoagulant Options for Atrial Fibrillation

The choice of anticoagulant for a 94-year-old patient with new onset Atrial Fibrillation (AF) depends on various factors, including the patient's risk of stroke and bleeding.

• Aspirin and Eliquis (Apixaban) are two options that have been studied in clinical trials.
• According to the AVERROES trial 3, apixaban was more effective than aspirin in preventing stroke or systemic embolism in patients with AF who were unsuitable for vitamin K antagonist treatment.
• The results of the AVERROES trial were further supported by a subgroup analysis 4, which demonstrated that apixaban was more efficacious than aspirin in patients ≥85 years old.

Efficacy and Safety of Apixaban

The efficacy and safety of apixaban compared to aspirin have been evaluated in several studies.

• A study published in the European Heart Journal 5 found that apixaban reduced the risk of stroke or systemic embolism by 55% compared to aspirin without an increase in major bleeding in patients with AF who had previously tried but failed treatment with vitamin K antagonists.
• Another study published in Current Medical Research and Opinion 6 found that apixaban was associated with a significantly lower risk of stroke/systemic embolism and major bleeding compared to rivaroxaban and warfarin in elderly nonvalvular atrial fibrillation patients.

Considerations for Elderly Patients

When considering anticoagulant therapy for elderly patients with AF, it is essential to weigh the benefits and risks of each option.

• A study published in Age and Ageing 4 found that older patients with AF are at particularly high risk of stroke if given aspirin and have substantially greater relative and absolute benefits from apixaban compared to younger patients with no greater risk of hemorrhage.
• However, another study published in Prescrire International 7 noted that apixaban is a substrate for various cytochrome P450 isoenzymes and for P-glycoprotein, creating a risk of multiple drug-drug interactions, and that renal function must be regularly monitored due to the increased anticoagulant action of apixaban in renal failure.