Early Anticoagulation of Bioprosthetic Aortic Valves in Older Patients: Results From the Society of Thoracic Surgeons Adult Cardiac Surgery National Database

Study Questions:

What are the risks and benefits of short-term anticoagulation in patients undergoing aortic valve replacement with a bioprosthesis?


Between 2004 and 2006, a cohort of 25,656 patients ≥65 years underwent aortic valve replacement with a bioprosthesis at 797 hospitals within the Society of Thoracic Surgeons Adult Cardiac Surgery Database. The associated 3-month incidences of death or readmission for embolic (cerebrovascular accident, transient ischemic attack, and noncerebral arterial thromboembolism) or bleeding events were compared with propensity methods across discharge anticoagulation strategies.


In this cohort (median age 77 years), the three most common discharge anticoagulation strategies included aspirin-only (49%), warfarin-only (12%), and warfarin plus aspirin (23%). Among those receiving aspirin-only, 3-month adverse events were low (death 3.0%, embolic events 1.0%, bleeding events 1.0%). Relative to aspirin-only, those treated with warfarin plus aspirin had a lower adjusted risk of death (relative risk [RR], 0.80; 95% confidence interval [CI], 0.66-0.96) and embolic event (RR, 0.52; 95% CI, 0.35-0.76), but a higher risk of bleeding (RR, 2.80; 95% CI, 2.18-3.60). Relative to aspirin-only, warfarin-only patients had a similar risk of death (RR, 1.01; 95% CI, 0.80-1.27), embolic events (RR, 0.95; 95% CI, 0.61-1.47), and bleeding (RR, 1.23; 95% CI, 0.85-1.79). These results were generally consistent across patient subgroups.


Death and embolic events were relatively rare in the first 3 months after bioprosthetic aortic valve replacement. Compared with aspirin-only, aspirin plus warfarin was associated with a reduced risk of death and embolic events, but at the cost of an increased bleeding risk.


Patients undergoing aortic valve replacement with a bioprosthesis have an elevated early risk of thromboembolic events; however, the risks and benefits of short-term anticoagulation have been debated with limited evidence. As evidenced by data in this study, the most common strategy early (and later) after bioprosthetic aortic valve replacement is to recommend aspirin only. Perhaps not surprisingly, the use of warfarin with or without aspirin resulted in both fewer thromboembolic events and more hemorrhagic events; there was a slightly lower risk of death with combined warfarin plus aspirin. Consideration probably should be given to the use of short-term therapy with combined warfarin plus aspirin after bioprosthetic aortic valve replacement, specifically among patients thought to be at low risk of bleeding.

Keywords: Bioprosthesis

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