Background: Patients with atrial fibrillation (AF) who also have heart failure have a worse outcome but the diagnosis of heart failure is often missed.
Aim: To compare the effects of warfarin and ximelagatran on morbidity and mortality in patients with AF with and without markers of heart failure.
Methods and results: Data for 7329 patients from two randomised controlled trials were merged. Treatment with loop diuretics or the presence of left ventricular dysfunction, were used as markers of possible heart failure. The 3555 (49%) patients with markers of heart failure had higher composite event rates on warfarin (10.81% per year [py] [95% CI 9.59 to 12.13]) compared to the 3774 (51%) patients without markers of heart failure (4.18% py [95% CI 3.44 to 5.01]). The composite event rate was lower on ximelagatran overall (6.18% py [95% CI 5.51 to 6.89] versus 7.34% py [95% CI 6.63 to 8.10] on warfarin; P=0.0219 for the difference) with similar effects in each trial and in patients with and without markers of heart failure, mainly due to fewer heart-failure events (hazard ratio 0.69 [95% CI 0.54 to 0.87]; P<0.001).
Conclusions: Patients with markers of heart failure, even if the diagnosis is not well established, are at increased risk of thromboembolic events and might be targeted for more effective antithrombotic therapy. This might include patients in sinus rhythm as well as AF.