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Atrial Fibrillation complications: What preventative treatments should be considered?

Heart, Stroke | March 29, 2016 | Author: The Super Pharmacist

heart, Stroke

Atrial Fibrillation complications: What preventative treatments should be considered?

Normally, electrical impulses move from across the smaller, upper chambers of the heart (i.e. atria) to the lower, larger chambers of the heart (i.e. ventricles). This electrical stimulation causes the chambers of the heart to contract in sequence, which generates blood pressure and pumps blood throughout the body.

In atrial fibrillation, the electrical impulses in the atria are abnormal. As a result, the chambers of the heart do not contract sequentially. This uncoordinated beating of the heart causes many short-term and long-term consequences.

Short-term atrial fibrillation complications

The ventricles are responsible for generating most of the blood pressure in the body. The right ventricle pumps blood to the lungs, while the left ventricle is responsible for pumping blood to the rest of the body. The atria provide a small, but important addition to blood pressure, called the “atrial kick.”

During atrial fibrillation, the atrial kick is lost. Loss of the atrial kick reduces cardiac output by 20 to 30% in otherwise healthy individuals and by even greater amounts in people with heart disease. As a result, people with atrial fibrillation may experience a drop in blood pressure (i.e. hypotension). This drop in blood pressure may cause people to become lightheaded or dizzy, or they may lose consciousness (i.e. pass out) because of lack of blood flow to the brain. Indeed, the most serious short-term complication of atrial fibrillation is reduced blood flow to the brain, the kidney, and other important organs (i.e. hemodynamic instability).

Atrial Fibrillation complications: What preventative treatments should be considered?

Intermediate and long-term atrial fibrillation complications

Abnormal electrical conduction in atrial fibrillation prevents the atria from properly squeezing blood into the ventricles. This not only reduces cardiac output and blood pressure, but it also causes blood to stagnate in the atria. Stagnant blood tends to form blood clots, which is a major concern in atrial fibrillation. Indeed, the most common serious complication of atrial fibrillation is arterial thromboembolism i.e. a blood clot within an artery. Arterial blood clots could break loose and travel through the bloodstream to the lungs or to the brain, where they may cause pulmonary embolism or stroke, respectively. Therefore, people with chronic atrial fibrillation may need to take anticoagulants to prevent blood clot formation in the atria.

Anticoagulant drugs reduce the risk of stroke in patients with atrial fibrillation

Antithrombotic therapy with an anticoagulant drug, such as warfarin, substantially reduces the risk of an arterial blood clot in patients with atrial fibrillation.There is a trade-off between the risk of clotting and the risk of bleeding, however. Treatment with warfarin increases a patient's risk of having a clinically significant episode of bleeding, such as gastrointestinal tract hemorrhage or hemorrhagic stroke. Newer anticoagulant medications are associated with less risk of serious bleeding, but the risk of bleeding with these newer medications is still greater than for someone who is not on anticoagulant treatment.Therefore, one must balance the risk of blood clots with the risk of bleeding.

Balancing risk between clotting and bleeding

When determining whether to use anticoagulant medications to prevent blood clots in patients with atrial fibrillation, physicians use a means of calculating risk called the CHA2DS2-VASc score. CHA2DS2-VASc is actually an acronym that corresponds to eight risk factors for complications arising from atrial fibrillation. Patients are assigned one point for each risk factor except for age greater than 75 years or a history of stroke, transient ischemic attack, or thromboembolism, which are each assigned two points. The maximum number of points that can be assigned is nine.

Risk Factors

Atrial Fibrillation complications: What preventative treatments should be considered?1. Stroke/transient ischemic attack/thromboembolism (2 points)

2. Congestive heart failure

3. Hypertension (i.e. high blood pressure

4. Age ≥75 years (2 points)

5. Diabetes mellitus

6. Vascular disease (prior myocardial infarction, peripheral arterial disease, etc.)

7. Age 65 to 74 years

8. Sex category (Female)


For most patients with atrial fibrillation, a CHA2DS2-VASc score of two or greater is considered high risk, and the risk of a stroke from a blood clot outweighs the risk of serious bleeding. As such, people in this risk category are treated with an oral anticoagulant in most cases.

A CHA2DS2-VASc score of zero is considered low risk and is not normally treated with oral anticoagulants.

People with atrial fibrillation who have a CHA2DS2-VASc score of one are neither high risk nor low risk of ischemic stroke. The decision whether to use anticoagulants in these individuals is much more complex. Patients with a CHA2DS2-VASc score of one may or may not be treated with oral anticoagulant medications. The decision whether or not to use oral anticoagulants is made on an individual basis by a cardiologist and the affected patient. Unfortunately, anticoagulants are unlikely to help most patients with a CHA2DS2-VASc score of one.

The choice of anticoagulant medication

Historically, warfarin was the only reliable oral anti-coagulation method for patients with atrial fibrillation.

The choice of anticoagulant medicationAs patients who have been prescribed warfarin well know, warfarin interacts with virtually all other medications and many foods. Consequently, finding the proper dose of warfarin is highly individualised. It usually requires patients to have frequent blood testing to determine their personal level of anticoagulation. Initially, blood tests may be required as often as once per week.

Fortunately, a number of oral anticoagulant medications are now available that do not require frequent blood testing. The active ingredient for these medications are apixaban, dabigatran, edoxaban, and rivaroxaban. Moreover, the risk of bleeding associated with these newer medications is less than it is for warfarin. Unfortunately, the cost of these newer medications can be considerably higher than it is for warfarin, which may be a concern for some patients with atrial fibrillation. Australia's best online chemist


Moukabary T, Gonzalez MD. Management of atrial fibrillation. Med Clin North Am. Jul 2015;99(4):781-794. doi:10.1016/j.mcna.2015.02.007

Alpert JS, Petersen P, Godtfredsen J. Atrial fibrillation: natural history, complications, and management. Annu Rev Med. 1988;39:41-52. doi:10.1146/

Freeman JV, Simon DN, Go AS, et al. Association Between Atrial Fibrillation Symptoms, Quality of Life, and Patient Outcomes: Results From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). Circ Cardiovasc Qual Outcomes. Jul 2015;8(4):393-402. doi:10.1161/circoutcomes.114.001303

Fedorowski A, Hedblad B, Engstrom G, Gustav Smith J, Melander O. Orthostatic hypotension and long-term incidence of atrial fibrillation: the Malmo Preventive Project. J Intern Med. Oct 2010;268(4):383-389. doi:10.1111/j.1365-2796.2010.02261.x

Stiell IG, Macle L. Canadian Cardiovascular Society atrial fibrillation guidelines 2010: management of recent-onset atrial fibrillation and flutter in the emergency department. Can J Cardiol. Jan-Feb 2011;27(1):38-46. doi:10.1016/j.cjca.2010.11.014

Pritchett ELC. Management of Atrial Fibrillation. New England Journal of Medicine. 1992;326(19):1264-1271. doi:doi:10.1056/NEJM199205073261906

Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials. Arch Intern Med. Jul 11 1994;154(13):1449-1457.

Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke. 1991;22(8):983-988.

Singer DE, Chang Y, Fang MC, et al. The net clinical benefit of warfarin anticoagulation in atrial fibrillation. Ann Intern Med. Sep 1 2009;151(5):297-305.

Connolly SJ, Ezekowitz MD, Yusuf S, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. Sep 17 2009;361(12):1139-1151. doi:10.1056/NEJMoa0905561

Granger CB, Alexander JH, McMurray JJ, et al. Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. Sep 15 2011;365(11):981-992. doi:10.1056/NEJMoa1107039

Friberg L, Rosenqvist M, Lip GY. Evaluation of risk stratification schemes for ischaemic stroke and bleeding in 182 678 patients with atrial fibrillation: the Swedish Atrial Fibrillation cohort study. Eur Heart J. Jun 2012;33(12):1500-1510. doi:10.1093/eurheartj/ehr488

Friberg L, Skeppholm M, Terent A. Benefit of anticoagulation unlikely in patients with atrial fibrillation and a CHA2DS2-VASc score of 1. J Am Coll Cardiol. Jan 27 2015;65(3):225-232. doi:10.1016/j.jacc.2014.10.052

Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. Sep 8 2011;365(10):883-891. doi:10.1056/NEJMoa1009638

Buller HR, Decousus H, Grosso MA, et al. Edoxaban versus warfarin for the treatment of symptomatic venous thromboembolism. N Engl J Med. Oct 10 2013;369(15):1406-1415. doi:10.1056/NEJMoa1306638

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