Chronic heart failure (CHF) is characterized by higher rates of atrial fibrillation (AF) and endothelial dysfunction (ED). First line anticoagulant therapy in AF is represented by direct oral anticoagulants (DOACs); several patients, however, are still treated with vitamin-K inhibitors. The use of DOACs is associated in previous studies with an improved vascular function. We therefore sought to evaluate possible changes in endothelial function assessed by flow-mediated dilation (FMD) in patients with CHF and AF shifting from warfarin to DOACs.
Forty-three consecutive outpatients were enrolled in the study. FMD was assessed at baseline and after 4 months. Patients were compared according to AC therapy.
After the first measurement of FMD, 18 patients “switched” to DOACs because of poor compliance to warfarin therapy or time in therapeutic range, 19 patients continued to use DOACs, 6 warfarin. “Switched” patients to DOACs therapy showed an improved FMD (19.0 ± 6.6% vs 3.8 ± 1.3%, p < 0.0001); C-reactive protein (CRP) levels decreased in "switched" patients from 1.4 ± 0.5 to 1.0 ± 0.7 mg/dl (p < 0.05). FMD and CRP changes were not significant in patients who did not changed anticoagulant therapy. In switched patients, changes in CRP levels were proportional to FMD changes (r = -0.50, p < 0.05). Shifting from warfarin to DOACs was significantly correlated to improved FMD levels even at multivariable analysis (p < 0.05).
Switch from warfarin to DOACs in patents with CHF and AF was associated in an observational non randomized study with an improved endothelial function. Changes in FMD values were related to changes in CRP levels.

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