Cost-effective medicines for stroke prophylaxis in patients with atrial fibrillation
Non-valvular atrial fibrillation is the most common arrhythmia encountered in clinical practice and is associated with substantial healthcare costs. The risk of thromboembolic stroke is 3-5 times higher in patients with atrial fibrillation compared with the general population. Until the recent emergence of direct thrombin (factor IIa) and factor Xa inhibitors, antithrombotic therapy for atrial fibrillation was achieved with antiplatelet agents or vitamin K antagonists, which are considered cost-effective strategies when compared to no treatment. Now newer agents, such as the direct thrombin inhibitor dabigatran, can lower thromboembolic events and reduce the risk of fatal and intracerebral hemorrhage compared with warfarin, in addition to eliminating the need for costly therapeutic monitoring. Multiple analyses have shown that dabigatran, when compared with warfarin therapy that achieves a time in therapeutic range (TTR) consistent with previous large-scale trials, is a cost-effective approach to antithrombotic therapy in atrial fibrillation, ranging from $16,385 to $86,000 per quality-adjust life-year (QALY) gained. It has been shown to be especially cost-effective (QALY < $50,000) for high stroke-risk patients, those with a CHADS2 score of > 3 (barring excellent INR control) and for lower-risk patients with a CHADS2 of 2 but concomitant high risk of hemorrhage. In addition, factor Xa inhibitors, such as rivaroxaban (recently approved by the Federal Drug Administration [FDA]) and apixaban, may exhibit the same cost savings as dabigatran in terms of reduction of bleeding and elimination of therapeutic level monitoring costs. Going forward, the use of these agents and their role in thromboembolic stroke prophylaxis will need to be evaluated on a patient-by-patient basis, balancing consideration of the patient's stroke and bleeding risks, as well as quality of life post-therapy.
