ANTICOAGULATION THERAPY The choice of anticoagulation treatment requires weighing the risks and benefits of oral anticoagulation therapy. Stroke and bleeding risks, cost, tolerability, potential for drug interactions, likelihood of patient adherence to the anticoagulation regimen, and patient preferences should be considered.1
The three oral anticoagulants recently approved by the FDA for the reduction of stroke and systemic embolism risks in nonvalvular A-fib are dabigatran, a direct thrombin inhibitor, and rivaroxaban and apixaban, both factor Xa inhibitors.12-14
The clinical trials upon which the FDA’s approval of these anticoagulants was based included only patients with nonvalvular A-fib. For patients with valvular disease, warfarin, a vitamin-K–dependent inhibitor, is currently recommended.1,15 It is also recommended for patients with both end-stage renal disease (ESRD) and either nonvalvular or valvular A-fib.1
A-fib and chronic kidney disease It is estimated that one-third of patients with A-fib are also diagnosed with chronic kidney disease (CKD).16 Because patients with CKD have a greater risk for bleeding, anticoagulant therapy for these patients requires reduced dosing and close monitoring for bleeding.
The 2014 ACC/AHA/HRS practice guidelines include guidance for selection of oral anticoagulants for patients with nonvalvular A-fib and CKD (see Table 3).1,12-14,17 Dosing of dabigatran and rivaroxaban require evaluation of creatinine clearance before treatment is initiated.
When warfarin is indicated, dose adjustments for renal impairment are based on the prothrombin time/international normalized ratio (INR) value.1 Current guidelines recommend maintaining a therapeutic INR between 2.0 and 3.0 for nonvalvular A-fib in patients with CKD.1 Patients with difficulty maintaining therapeutic INR levels may benefit from alternate therapy with Xa inhibitors or a direct thrombin inhibitor except in the presence of ESRD.1
