Atrial Fibrillation: Stroke Prevention Guidelines & Treatment Options
Atrial Fibrillation and Stroke Prevention: The Basics
During AF, electrical activity in the heart is disorganized and the heart's blood flow is disrupted. When the blood cannot flow properly, it may pool in the heart chambers and cause a blood clot. These clots can dislodge from the heart and travel towards the brain, blocking a blood vessel and causing a stroke. Because of this, a patient with chronic AF usually takes a blood thinning medication to help prevent a stroke.
AF Sounds Serious: Is It Common?
According to the American Academy of Neurology, roughly 1 in 20 people with untreated AF will likely have an ischemic stroke in the next year. Treatment for stroke prevention in AFib includes warfarin plus several anticoagulants approved since 2010 giving patients and doctors newer options.
What Factors Put Me at A Higher Risk for Getting AF?
There are many risk factors that may increase your chances of having non-valvular AF including: advanced age, heart disease, heart damage or a heart attack, high blood pressure, stress, high thyroid hormone levels (hyperthyroidism), excessive alcohol intake, stimulating drugs like caffeine, congestive heart failure, obstructive sleep apnea, or acute infections.
Tell Me More About AF Symptoms
Some people with AF have no symptoms and only get a diagnosis after a physical exam and testing by their doctor, or after a stroke or mini-stroke. For patients that have symptoms, they may complain that their heart flutters, quivers, palpates or beats against the chest wall. They may feel dizzy, weak and nauseated. They may also have shortness of breath or fainting spells. Chest pain or tightness, confusion or fatigue may be present.
Why Does AF Lead to a Higher Risk for a Stroke?
Roughly 9 out of 10 strokes caused by AF are an ischemic stroke. Taking a blood thinner can reduce the risk of having a stroke by 50 to 70 percent.
Use the acronym F.A.S.T. to recognize a stroke in others: Face dropping, Arms drifting down, Slurred Speech, Time to call 911.
How is AF Diagnosed?
The diagnosis of AF is usually confirmed with an electrocardiogram (EKG), a test that records the heart's electrical activity. However, atrial fibrillation may not always be constant, so a standard EKG may be normal and it may be difficult to detect abnormalities in an office visit. In these cases, a portable EKG, called a Holter monitor, may be worn at home, for 24 hours. Monitors are also available that can be used for longer than 24 hours, if needed.
AF Treatment: The Basics
Working in conjunction with their physician, patients may receive treatments that will correct the heart rhythm (cardioversion), undergo surgery, and/or take medications such as blood thinners, antiarrhythmics, beta-blockers, calcium channel blockers (verapamil, diltiazem) or digoxin. The use of pacemakers or radiofrequency ablation are nondrug alternatives.
Warfarin for Stroke Prevention in AF: Benefits and Risks
The novel oral anticoagulants Eliquis (apixaban), Pradaxa (dabigatran), Savaysa (edoxaban), or Xarelto (rivaroxaban) may be an alternative for patients currently taking warfarin. Your doctor will determine this.
Other Treatments for Stroke Prevention in AF
In patients with non-valvular AF who are at risk for stroke, using an oral anticoagulant therapy, such as warfarin or the novel agents, is likely more effective than using aspirin plus clopidogrel (Plavix), but the bleeding risk may be slightly higher.
Stroke Prevention in Non-Valvular AF
The novel blood thinners, including Pradaxa, Xarelto, Savaysa, and Eliquis are now available - they work as good or better than warfarin, are less likely to cause bleeding in the brain, and don’t require regular blood tests or dietary restrictions like warfarin.
How Do Risk Factors Affect Treatment Choice in AF?
In patients with a higher risk for a stomach bleed, Eliquis may be the treatment of first choice. If a patient is well-controlled on warfarin, a change to a newer oral anticoagulant is not absolutely required. According to the guidelines, if warfarin is not an option, consider apixaban as the first drug of choice (Level B evidence), then either dabigatran or rivaroxaban (Level C). Aspirin plus clopidogrel is an option in those who cannot use warfarin, but bleeding risk may be greater.
Novel Oral Anticoagulants: Pradaxa (dabigatran)
Pradaxa is used to prevent stroke or systemic embolism in patients with non-valvular atrial fibrillation, and does not require regular blood testing for therapeutic effectiveness like warfarin. Studies have shown that the rates of stroke or systemic embolism were lower with dabigatran than with warfarin, rates of intracranial (brain) bleeding occurred less frequently, but GI bleeding may be greater. Pradaxa is also approved for treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), as well as prevention of DVT and PE following hip replacement surgery.
Take Note: Pradaxa Dosing and Storage
An important note: Pradaxa should be stored in the original container; do not put the capsules in pill boxes. Once the Pradaxa bottle is opened, the capsules are stable for only 4 months.
Stomach upset (dyspepsia) is a common side effect with Pradaxa. Patients should not stop taking any blood thinner (anticoagulant) medicine without first talking to their doctor. Discontinuing anticoagulation medicine puts a patient at an increased risk of having a stroke.
Novel Oral Anticoagulants: Xarelto (rivaroxaban)
Xarelto is also approved for prevention or treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), as well as prevention of DVT Following hip or knee replacement surgery . The Xarelto NDA for use in acute coronary syndrome was not approved as trials pointed to major bleeding concerns.
Novel Oral Anticoagulants: Eliquis (apixaban)
Eliquis is taken twice a day and lower doses may be needed if the patient has kidney impairment, lower body weight, or age older than 80 years.
Eliquis has important drug interactions, too, so always have your pharmacist run a drug interaction check when medications are started or stopped.
Novel Oral Anticoagulants: Savaysa (edoxaban)
In AF clinical trials, Savaysa was found to be similar to warfarin for reduced stroke risk and demonstrated significantly less major bleeding compared to warfarin. However, bleeding - including life-threatening bleeding - is still the most serious risk with Savaysa. No antidote is available to reverse the anticoagulant effect of Savaysa.
Antidotes for Newer Oral Anticoagulants
With warfarin, (a vitamin K antagonist), vitamin K can be given as an antidote to help stop bleeding.
Patients with Prosthetic Heart Valves
Patients with atrial fibrillation should NOT stop taking anticoagulants without first talking to their healthcare professional. Abruptly stopping anticoagulants such as warfarin, Pradaxa, Xarelto, Savaysa or Eliquis can increase the risk of stroke, leading to permanent disability or death.
Cost Concerns with Novel Anticoagulants
The newer anticoagulants, while they do not require blood tests, are expensive, costing roughly $300 per month; your insurance may pay for a portion of this cost. Cost-savings may be available through the manufacturer, too. Some people well-controlled on warfarin may not need to switch to a newer agent. Always discuss the best regimens with your doctor.
Finished: Atrial Fibrillation - Stroke Prevention Guidelines & Treatment Options
- American Academy of Neurology. Summary of Evidence-Based Guidelines for Clinicians. Prevention of Stroke in Nonvalvular Atrial Fibrillation. 2014. Accessed May 9, 2014 at https://www.aan.com/Guidelines/Home/GetGuidelineContent/635
- Dentali F et al. Efficacy and safety of the novel oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of the literature. Circulation. 2012;126:2381-91
- Granger CB et al. Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2011;365:981-92
- Patel MR et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365:883-91
- Boehringer Ingelheim Inc. Press Release. Setting the Record Straight: The Facts about Pradaxa (dabigatran etexilate mesylate). February 13, 2014. Accessed March 1, 2014 at http://us.boehringer-ingelheim.com/news_events/press_releases/press_release_archive/2014/02-13-2014-setting-the-record-straight-facts-pradaxa-dabigatran-etexilate-mesylate.html
- Connolly SJ et al; RE-LY Steering Committee and Investigators. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009;361:1139-51
- The Centers for Disease Control and Prevention (CDC). Division for Heart Disease and Stroke Prevention. Atrial Fibrillation Fact Sheet. Accessed March 2, 2014 at http://www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_atrial_fibrillation.htm.
- CardioSmart. American College of Cardiology. Atrial Fibrillation Guidelines 2014. Accessed April 9, 2014 at https://www.cardiosmart.org/Heart-Conditions/Guidelines/Atrial-Fibrillation-Guidelines-2014