Clinical effectiveness of anticoagulation therapy among older patients with heart failure and without atrial fibrillation: findings from the ADHERE registry linked to Medicare claims.

Background: Patients with heart failure are at higher risk for thromboembolic events, even in the absence of atrial fibrillation, but the effect of anticoagulation therapy on outcomes is uncertain.
Methods and Results: With data from a clinical registry linked to Medicare claims, we estimated the adjusted associations between anticoagulation and 1-year outcomes with the use of inverse probability of treatment weighting. Eligible patients had an ejection fraction ≤35%, had no concurrent atrial fibrillation, were alive at discharge, and had not received anticoagulation therapy before admission. Of 13,217 patients in 276 hospitals, 1,140 (8.6%) received anticoagulation therapy at discharge. Unadjusted rates of thromboembolic events and major adverse cardiovascular events did not differ by receipt of anticoagulation therapy. Patients discharged on anticoagulation therapy had lower unadjusted rates of all-cause mortality (27.2% vs 32.3%; P < .001) and readmission for heart failure (29.4% vs 35.4%; P < .001) and higher rates of bleeding events (5.2% vs 2.8%; P < .001). After adjustment for probability of treatment and discharge medications, there were no differences in all-cause mortality (hazard ratio 0.92; 95% confidence interval 0.80-1.06) or readmission for heart failure (0.91, 0.81-1.02), but patients receiving anticoagulation therapy were at higher risk for bleeding events (2.09, 1.47-2.97).
Conclusions: Anticoagulation therapy at discharge is infrequent among older patients with heart failure and without atrial fibrillation. There were no statistically significant propensity-weighted associations between anticoagulation therapy and 1-year outcomes, except for a higher risk of bleeding.
(Copyright © 2013 Elsevier Inc. All rights reserved.)