The Costs of an Irregular Heartbeat

A new study estimates the costs of treating atrial fibrillation as well as the comparative costs of treating it with warfarin and newer oral anticoagulants.

Atrial fibrillation (AF)—irregular, often rapid heartbeat—is closely linked to other cardiovascular diseases. Patients who have AF often have or develop heart failure, coronary artery disease (CAD), diabetes mellitus, hypertension, or valvular heart disease. Patients with AF are also at 4- to 5-times greater risk of stroke than are those who do not have AF.

AF’s predisposing risk factors and pathologic mechanisms are not fully understood. With 2.3 million Americans affected by AF, researchers are keenly interested in determining why this condition develops, how to prevent it, and the most effective treatments. The most common treatment is with anticoagulants to prevent stroke.

Until quite recently, warfarin was the only oral anticoagulant available. Warfarin’s limitations are well documented: It requires frequent monitoring, and patients exhibit widely variable responses that can increase the risk of bleeding or stroke. In addition, its many food and drug interactions pose challenges to patients and clinicians alike. Newer oral anticoagulants (eg, dabigatran, rivaroxaban, apixaban) offer more predictable anticoagulation without laboratory monitoring, but are comparatively costly.

An article published in the November/December 2013 issue of the Journal of Managed Care Pharmacy investigates whether the reduction in clinical events associated with the newer oral anticoagulants reduces medical costs and offsets their higher unit cost. The researchers used a literature search to identify studies conducted in the United States that examined anticoagulants for stroke prophylaxis in AF patients. Studies had to address costs of laboratory monitoring, bleeding, and stroke.

Much of what they found focused on short-term, in-hospital expenditures without attention to long-term care costs. Regardless, they were able to find ample data on AF-associated costs. They broke costs into 3 areas: (1) the costs of monitoring warfarin, (2) the direct costs of managing anticoagulant therapy’s adverse events (stroke and bleeding), and (3) the drug’s cost. Results were reported in 2011 US dollars.

The researchers determined that treating AF patients in the United States costs between $18,454 and $38,270 per year. Annual incremental costs (the cost of treating a patient with comorbid AF compared to a patient without AF) ranged from $8705 to $16,311. The annual costs of regular laboratory monitoring to ensure that patients remain within the narrow therapeutic range fell into a wide range: $291 to $943 per patient.

Patients who suffered rare but costly major complications while on oral anticoagulants (intracranial hemorrhage and major gastrointestinal bleeding) incurred costs of $7584 to $193,804 each year with about 50% of costs related to hospitalization. Studies documented annual inpatient costs from $7841 to $22,582 per patient. Annual direct costs of stroke in AF patients ranged from $23,143 to $37,620 (incremental cost of $7824 to $8232 versus stroke patients without AF).

A strength of this review is its focus on real-world situations based on observational study. The authors included information on transportation costs and comorbidities in addition to other costs. They did not come to specific conclusions, instead calling for more study that takes local health care costs, drug adherence, population risk, and health behaviors into account.

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.