In addition to Warfarin ( Coumadin ), there are four non-vitamin K antagonist oral anticoagulants ( NOACs ) available for stroke prevention in non-valvular atrial fibrillation ( NVAF ).
There are limited data on the comparative risks of major bleeding among newly anticoagulated patients with non-valvular atrial fibrillation who initiate Warfarin, Apixaban ( Eliquis ), Dabigatran ( Pradaxa ), or Rivaroxaban ( Xarelto ), when used in 'real world' clinical practice.
The study used the Truven MarketScan Commercial & Medicare supplemental US claims database.
Patients with non-valvular atrial fibrillation, aged greater than or equal to 18 years, newly prescribed an oral anticoagulant during 2013-2014, with a greater than or equal to 1-year baseline period, were included ( study period: 2012-2014 ).
Major bleeding was defined as bleeding requiring hospitalisation.
Among 45,361 newly anticoagulated NVAF patients, 15,461 ( 34.1% ) initiated Warfarin, 7,438 ( 16.4 % ) initiated Apixaban, 17,801 ( 39.2 % ) initiated Rivaroxaban, and 4,661 ( 10.3 % ) initiated Dabigatran.
Compared to matched Warfarin initiators, Apixaban ( hazard ratio, HR=0.53; 95 % CI: 0.39-0.71 ) and Dabigatran ( HR=0.69; 95 % CI: 0.50-0.96 ) initiators had a significantly lower risk of major bleeding.
Patients initiating Rivaroxaban ( HR=0.98; 95 % CI: 0.83-1.17 ) had a non-significant difference in major bleeding risk compared to matched Warfarin patients.
When comparisons were made between non-vitamin K antagonist oral anticoagulants, matched Rivaroxaban patients had a significantly higher risk of major bleeding ( HR=1.82; 95 % CI: 1.36-2.43 ) compared to Apixaban patients.
The differences for Apixaban - Dabigatran and Dabigatran - Rivaroxaban matched cohorts were not statistically significant.
Among newly anticoagulated patients with non-valvular atrial fibrillation in the real-world setting, Apixaban and Dabigatran initiation was associated with significantly lower risk of major bleeding compared to Warfarin initiation.
When compared to Apixaban, Rivaroxaban initiation was associated with significantly higher risk of major bleeding. ( Xagena )
Lip GY et al, Thromb Haemost 2016;116:975-986