Nonvitamin K antagonist oral anticoagulants ( NOACs ) are alternatives to Warfarin ( Coumadin ) in patients with nonvalvular atrial fibrillation.
Randomized trials compared NOACs with Warfarin, but none have compared individual NOACs against each other for safety and effectiveness.
Researchers have performed a retrospective new-user cohort study of patients with nonvalvular atrial fibrillation enrolled in US Medicare who initiated Warfarin ( n = 183,318 ), or a standard dose of Dabigatran [ Pradaxa ] ( 150 mg twice daily; n = 86,198 ), Rivaroxaban [ Xarelto ] ( 20 mg once daily; n = 106,389 ), or Apixaban [ Eliquis ] ( 5 mg twice daily; n = 73,039 ) between October 2010 and September 2015.
Propensity score-adjusted Cox proportional hazards regression was used to estimate adjusted hazard ratios ( HR ) and 95% confidence intervals ( CI ) for the outcomes of thromboembolic stroke, intracranial hemorrhage, major extracranial bleeding, and all-cause mortality, comparing each NOAC with Warfarin, and with each other NOAC.
Compared with Warfarin, each NOAC was associated with reduced risks of thromboembolic stroke ( 20%-29% reduction; P = 0.002 [ Dabigatran ], P less than 0.001 [ Rivaroxaban, Apixaban ] ), intracranial hemorrhage ( 35%-62% reduction; P less than 0.001 [ each NOAC ] ), and mortality ( 19%-34% reduction; P less than 0.001 [ each NOAC ] ).
The NOACs were similar for thromboembolic stroke but Rivaroxaban was associated with increased risks of intracranial hemorrhage ( vs Dabigatran: HR = 1.71; 95% CI, 1.35-2.17 ), major extracranial bleeding ( vs Dabigatran: HR = 1.32; 95% CI, 1.21-1.45; vs Apixaban: HR = 2.70; 95% CI, 2.38-3.05 ), and death ( vs Dabigatran: HR = 1.12; 95% CI, 1.01-1.24; vs Apixaban: HR = 1.23; 95% CI, 1.09-1.38 ). Dabigatran was associated with reduced risk of intracranial hemorrhage ( HR = 0.70; 95% CI ,0.53-0.94 ) and increased risk of major extracranial bleeding ( HR = 2.04; 95% CI, 1.78-2.32 ) compared with Apixaban.
In conclusion, among patients treated with standard-dose NOAC for nonvalvular atrial fibrillation and Warfarin users with similar baseline characteristics, Dabigatran, Rivaroxaban, and Apixaban were associated with a more favorable benefit-harm profile than Warfarin.
Among NOAC users, Dabigatran and Apixaban were associated with a more favorable benefit-harm profile than Rivaroxaban. ( Xagena )
Graham DJ et al, Am J Med 2019;132: 596-604