Warfarin plus Aspirin After Aortic Valve Prosthesis Placement?
An observational study suggests that the combination reduces mortality, at the cost of increased bleeding, when used in the 3 months after surgery.Patients receiving an aortic bioprosthesis have a low overall risk for thromboembolism, but controversy surrounds whether they benefit from anticoagulation in the first months after surgery. To address this issue, researchers used the Society of Thoracic Surgeons Adult Cardiac Surgery Database to compare the effectiveness of the early use of aspirin alone, aspirin plus warfarin, and warfarin alone.
The sample included 25,656 patients aged 65 (median age, 77; 39% women) who received an isolated aortic valve prosthesis at 797 hospitals from 2004 through 2006. At 3 months, the mortality rate was 3.0% in the aspirin-only group, 3.1% in the aspirin-plus-warfarin group, and 4.0% in the warfarin-only group. In the multivariable analysis, the addition of warfarin to aspirin was associated with a 20% relative reduction in risk for death (0.6% absolute risk reduction). Mortality with warfarin alone was no different than with aspirin alone. The addition of warfarin to aspirin was associated with 48% relative reduction in the risk for embolic events (0.4% absolute risk reduction). Again, warfarin alone was not associated with a reduction. Bleeding was more common in patients treated with warfarin plus aspirin than in those treated with aspirin only or warfarin only (2.8% vs. 1.0% and 1.4%, respectively).
Brennan JM et al. on behalf of the DEcIDE AVR Research Team. Early anticoagulation of bioprosthetic aortic valves in older patients: Results from the Society of Thoracic Surgeons Adult Cardiac Surgery National Database. J Am Coll Cardiol 2012 Sep 11; 60:971.