How does Eliquis work for AFib?

Having a severe and disabling stroke is likely one of your most feared health outcomes. As a frequent cause of stroke, the heart condition atrial fibrillation (AFib) is worth knowing more about. The knowledge could help you recognize the condition and seek preventive measures to avoid a stroke. 

AFib is the most common heart arrhythmia or disturbance of the heart’s electrical rhythm, afflicting more than 33 million people according to an estimate in 2010. It can be an intermittent or persistent problem. The risk of stroke with AFib is approximately 6% annually, although the risk varies considerably based on age and medical risk factors. 

During AFib, your heart’s top chambers, the atria, quiver rather than beat rhythmically. This sends erratic electric signals to your heart’s pumping chambers, the ventricles, resulting in a fast and irregular heartbeat. The symptoms can include palpitations, dizziness, fatigue, chest pain and shortness of breath, but AFib can also be present without any obvious symptoms. During the arrhythmia, the quivering atria are the formation point for blood clots, which can travel out of the heart and to the brain, producing strokes. 

Anticoagulants, also known as blood thinners, are an effective method for reducing stroke risk in AFib. One such anticoagulant, Eliquis (apixaban), has grown in usage in recent years and will be our focus. You will learn about the drug’s effectiveness, adverse effects, and alternatives.

What is Eliquis?

Eliquis is a member of the direct oral anticoagulant (DOAC) family of medications. The drug shifts your bodily mechanisms away from blood clot formation by inhibiting factor Xa. Ideally, our bodies are in a natural balance of being able to form blood clots when necessary, such as when we are cut, and preventing unnecessary blood clots. A cascade of enzyme triggers, including factor Xa, is partly responsible for clot formation. Unfortunately, certain conditions like AFib can upset the balance in the direction of an increased risk of blood clots. By blocking factor Xa, Eliquis can help to correct this. It is indicated by the Food and Drug Administration (FDA) for use in the following conditions.

• Prevention of thromboembolism (blood clot that travels to the body) and stroke in the setting of nonvalvular atrial fibrillation without moderate to severe mitral stenosis or a mechanical heart valve
• Prevention of deep vein thrombosis (DVT or blood clot in the veins) after knee or hip replacement surgery
• Prevention of recurrent DVT or pulmonary embolism (PE or blood clot in the lungs)
• Treatment of DVT or PE

How does Eliquis work for AFib?

The left atrium is the top left heart chamber, and it has a small pouch projecting off of it, called the left atrial appendage (LAA). In AFib, as blood is not being effectively pumped out of the left atrium, there is stagnant blood within the LAA. Ninety percent of the stroke-causing blood clots in AFib form within the LAA. A critical step in clot formation is production of the enzyme thrombin, and thrombin requires factor Xa for activation. By inhibiting factor Xa, Eliquis can reduce thrombin activation and hence blood clot formation. If you have Afib, taking Eliquis can significantly reduce your risk of stroke.

How effective is Eliquis for AFib?

For many years, warfarin (generic version of Jantoven and Coumadin) was the gold standard for stroke prevention in AFib. The drug had proven efficacy, reducing stroke risk in one study from 10% per year in AFib patients taking aspirin to 4% per year by taking warfarin instead. However, frequent blood test monitoring and variable blood thinning that is affected by dietary intake and drug interactions made warfarin an imperfect solution. 

The search for an alternative led to the development of the DOAC drug class. To prove their worth, DOACs had to compare favorably to warfarin. Eliquis did just that in the landmark ARISTOTLE clinical trial published in 2011, lowering annual stroke risk in that AFib population to 1.27% compared to 1.6% with warfarin. Eliquis also had a lower risk of bleeding than warfarin in the study. Furthermore, it is not affected by dietary intake and does not require frequent lab monitoring.

RELATED: Eliquis vs. warfarin

Since then, Eliquis has continued to gain favor. Clinical studies have been able to compare Eliquis with other members of the DOAC class. A recent review of these studies ranked Eliquis highest for efficacy and safety. It is no wonder why nearly $13 billion was spent on Eliquis in the United States in 2020, an expenditure growth of nearly 30%, putting it in second place for pharmaceuticals spending. The price of Eliquis may be prohibitive for some individuals, so they may still choose warfarin for this reason. In addition, Eliquis requires twice daily dosing, which is enough of an inconvenience for some to choose a once daily DOAC like Xarelto (rivaroxaban) instead.

RELATED: Eliquis vs. Xarelto for AFib

Eliquis dosing for AFib

Dosing of Eliquis depends on the particular indication for use. Occasionally, dosing can vary based on age, weight, and kidney function. For AFib, the standard Eliquis dose is 5 mg twice daily. The dosing in AFib may be decreased to 2.5 mg twice daily if two or more of the following factors are present, age 80 years or older, weight less than 60 kg, and serum creatinine (blood test of kidney function) more than 1.5 mg/dL. Of note, there are no approved uses in pediatrics.

Eliquis starts to work within a few hours of the first dose, a marked difference compared to warfarin, which typically takes days to get to a therapeutic level. Eliquis also wears off much quicker compared to warfarin. This is a nice feature if you have an upcoming planned surgery and do not have to be off your anticoagulant as long before its effect wears off. Unfortunately, the short, 12-hour half-life of Eliquis requires twice-daily dosing and means that if you miss a dose or two, you are back to being at a high risk of stroke from AFib.

The decision to start Eliquis or any anticoagulant for stroke prevention in Afib must be individualized. Among those with AFib, stroke risk can be vastly different, so you will want to get medical advice from your healthcare provider. Factors used to calculate your stroke risk may include age, gender, obesity, and the prior medical history of diabetes, hypertension, congestive heart failure, vascular disease, and stroke. If your risk is calculated to be very low, an anticoagulant may not be the right choice for you. If your risk is judged to be significant, an anticoagulant may be advised as long as your bleeding risk is not excessive. Once begun, the anticoagulant is usually continued indefinitely unless something changes with respect to your health.

Eliquis side effects and restrictions

The adverse effect profile of Eliquis is important to recognize. Bleeding is listed as a possible side effect of Eliquis, as is anemia and nausea. There is a greater risk of bleeding if Eliquis is taken with nonsteroidal anti-inflammatory drugs (NSAIDs). Serious side effects can include low platelet cell counts, passing out, and bleeding within the spine. In fact, the FDA has applied a black box warning to Eliquis and other DOACs regarding the heightened risk of spinal hemorrhage during and after spinal procedures in patients taking these anticoagulants. A different warning calls attention to the elevated risk of blood clot if Eliquis or other DOACs are stopped without adequate reason.

Active major bleeding, pregnancy, severe liver disease, antiphospholipid disease, allergic hypersensitivity reactions to the drug, or severe PE causing low blood pressure or requiring surgery or thrombolysis (clot busting medication) are some of the valid reasons why a healthcare professional might take you off Eliquis. They constitute contraindications to its use. Significant bleeding risk, advanced age, low bodyweight, substantial kidney function impairment, and the potential for pregnancy or breastfeeding are some reasons for additional caution and higher risk when starting Eliquis.

How to get prescribed Eliquis for AFib

Having read about the advantages and risks of Eliquis, you may be interested in starting on the drug for AFib-related stroke risk reduction. Eliquis is often prescribed by your primary care provider (an internal medicine or family practice provider) or by a cardiologist, a specialist in diseases of the heart and circulatory system. If a stroke has already occurred, a neurologist or specialist in the brain and nervous system could be the one to prescribe Eliquis. When considering whether to prescribe you Eliquis, the healthcare professional will likely calculate your risk of stroke from AFib and consider your bleeding risk as well.

Alternatives to Eliquis for AFib 

Despite scientific reviews calling Eliquis the most effective and safest anticoagulant for stroke risk reduction in AFib, it may not be the right choice for you. Contraindications to Eliquis may require that you choose another option. A high out-of-pocket cost for Eliquis or difficulty in complying with the required twice daily dosing of Eliquis could be other reasons to opt for an alternative. Warfarin may be chosen for those with advanced kidney disease, mechanical heart valves, or significant mitral stenosis.

The antiplatelet agents aspirin and Plavix (clopidogrel) have been evaluated for stroke prevention in Afib. Even when aspirin and Plavix were combined together, these agents were found to be much less effective than warfarin. Although a benefit was found, the antiplatelet agents were inferior to anticoagulation.

Besides determining an anticoagulation strategy for your AFib, you should evaluate other aspects of your health as they pertain to AFib. Properly addressing obesity, diabetes, hypertension, obstructive sleep apnea, and heart disease can be beneficial since they relate to AFib. Alcohol abstinence and a Mediterranean style diet may also be advantageous. 

Review all your options and get your questions answered by seeing your primary care provider or cardiologist. Gather information about AFib from trusted resources like the American Heart Association. Being an active member of your healthcare team and getting informed can empower you to reduce your risk of stroke with atrial fibrillation.