Antithrombotic therapy in heart failure patients with and without atrial fibrillation: update and future challenges

Atrial fibrillation (AF) and heart failure (HF) often coexist, and patients with AF and HF have a higher risk of thromboembolic events and overall mortality compared with those with AF without HF. Additionally, the prevalence of AF increases with the severity of HF. The use of vitamin K antagonists is more unstable in patients with concomitant AF and HF, which is an independent risk factor for reduced time under therapeutic range. More recently, non-vitamin K antagonists oral anticoagulants (NOACs) have emerged as therapeutic alternatives for stroke prevention in patients with non-valvular AF, as they have been shown to be at least as efficacious and safe, with less intracranial bleeding events, compared with vitamin K antagonists. The subgroup analyses of the NOAC trials in patients with AF and HF show that the efficacy and safety of these agents are likely to be similar to those observed in patients with AF and no HF. However, many gaps in evidence exist, since HF has not been consistently defined nor used as an endpoint in these trials. In patients with HF and sinus rhythm, the risk of stroke and other thrombotic events is high, and the use of warfarin has not, to date, been shown to confer outcome benefit. The benefit of the NOAC, rivaroxaban, is being investigated in HF without AF in the ongoing COMMANDER-HF trial. This review aims to provide an insightful perspective on the use of antithrombotic treatments in patients with both AF and HF, and in patients with HF and sinus rhythm, with particular attention to the NOACs, and provides background for therapeutic, outcome and trial improvement.