Reasons for and consequences of oral anticoagulant underuse in atrial fibrillation with heart failure.

OBJECTIVE

Atrial fibrillation (AF) is common in patients with heart failure (HF), and oral anticoagulants (OAC) are indicated. The aim was to assess prevalence of, predictors of and consequences of OAC non-use.

METHODS

We included patients with AF, HF and no previous valve replacement from the Swedish Heart Failure Registry. High and low CHA2DS2-VASc and HAS-BLED scores were defined as above/below median. Multivariable logistic regressions were used to assess the associations between baseline characteristics and OAC use and between CHA2DS2-VASc and HAS-BLED scores and OAC use. Multivariable Cox regressions were used to assess associations between CHA2DS2-VASc and HAS-BLED scores, OAC use and two composite outcomes: all-cause death/stroke and all-cause death/major bleeding.

RESULTS

Of 21 865 patients, only 12 659 (58%) received OAC. Selected predictors of OAC non-use were treatment with platelet inhibitors, less use of HF treatments, paroxysmal AF, history of bleeding, no previous stroke, planned follow-up in primary care, older age, living alone, lower income and variables associated with more severe HF. For each 1-unit increase in CHA2DS2-VASc and HAS-BLED, the ORs (95% CI) of OAC use were 1.24 (1.21-1.27) and 0.32 (0.30-0.33), and the HRs for death/stroke were 1.08 (1.06-1.10) and for death/major bleeding 1.18 (1.15-1.21), respectively. For high versus low CHA2DS2-VASc and HAS-BLED, the ORs of OAC use were 1.23 (1.15-1.32) and 0.20 (0.19-0.21), and the HRs for death/stroke were 1.25 (1.19-1.30) and for death/major bleeding 1.28 (1.21-1.34), respectively.

CONCLUSIONS

Patients with AF and concomitant HF do not receive OAC on rational grounds. Bleeding risk inappropriately affects decision-making more than stroke risk.