Background
Patients with atrial fibrillation (AF) are prone to cardiovascular events and anticoagulation-related
bleeding complications. We hypothesized that patients with anemia are at increased risk for these outcomes.
Methods
We performed a post hoc analysis of the ARISTOTLE trial, which included
N
18,000 patients with AF
randomized to warfarin (target international normalized ratio, 2.0-3.0) or apixaban 5 mg twice daily. Multivariable Cox
regression analysis was used to determine if anemia (defined as hemoglobin
b
13.0 in men and
b
12.0 g/dL in women) was
associated with future stroke, major bleeding, or mortality.
Results
Anemia was present at baseline in 12.6% of the ARISTOTLE population. Patients with anemia were older, had
higher mean CHADS
2
and HAS-BLED scores, and were more likely to have experienced previous bleeding events. Anemia was
associated with major bleeding (adjusted hazard ratio [HR], 1.92; 95% CI, 1.62-2.28;
P
b
.0001) and all-cause mortality
(adjusted HR, 1.68; 95% CI, 1.46-1.93;
P
b
.0001) but not stroke or systemic embolism (adjusted HR, 0.92; 95% CI, 0.70-
1.21). The benefits of apixaban compared with warfarin on the rates of stroke, mortality, and bleeding events were consistent
in patients with and without anemia.
Conclusions
Chronic anemia is associated with a higher incidence of bleeding complications and mortality, but not of
stroke, in anticoagulated patients with AF. Apixaban is an attractive anticoagulant for stroke prevention in patients with AF
with or without anemia. (Am Heart J 2017;185:140-9.)