Overestimation of risk of bleeding leads to underuse of oral anticoagulants in frail elderly heart failure patients with atrial fibrillation (AF) despite their increased risk of stroke, a study in Heart has concluded.

The authors of this study set out to assess the use of oral anticoagulants in patients with heart failure, specifically the prevalence, predictors and consequences of non-use.

Patients from the Swedish Heart Failure Registry with AF and heart failure but with no history of valve replacement were studied.

The authors assessed the associations between baseline patient characteristics and oral anticoagulant use and between CHA2DS2-VASc and HAS-BLED scores and oral anticoagulant use. They also assessed associations between CHA2DS2-VASc and HAS-BLED scores, oral anticoagulant use and two composite outcomes: all-cause death/stroke and all-cause death/major bleeding.

Of 21,865 patients, only 12, 659 (58%) received oral anticoagulants. Mean age was 74 (± 10) years in those patients who received anticoagulants and 79 (± 10) years in those who did not. The predictors for non-use of oral anticoagulants were: treatment with platelet inhibitors, less use of heart failure treatments, paroxysmal AF, history of bleeding, comorbidities, no previous stroke, planned follow-up in primary care, older age, living alone, lower income and variables associated with more severe heart failure.

After adjusting for potential confounders, for each unit increase in CHA2DS2-VASc and HAS-BLED, the odds ratio (OR) of oral anticoagulant use was OR 1.24 (95% CI: 1.21-1.27) and OR 0.32 (95% CI: 0.30-0.33) respectively, and the hazard ratio (HR) for death/stroke was HR 1.08 (95% CI: 1.06-1.10) and for death/major bleeding HR 1.18 (95% CI: 1.15-1.21), respectively.

For high vs low CHA2DS2-VASc and HAS-BLED, the OR of oral anticoagulant use was 1.23 (95% CI: 1.15-1.32) and 0.20 (95% CI: 0.19-0.21), respectively, and the HR for death/stroke 1.25 (95% CI: 1.19-1.30) and for death/major bleeding 1.28 (95% CI: 1.21-1.34), respectively.

AF can be a common occurrence in patients with heart failure whether as a consequence of another underlying cardiac pathology or as a cause of impaired cardiac function. Guidelines give clear direction on the use of oral anticoagulation to reduce the risk of thromboembolic complications.

The authors noted that frailty status, underestimation of thrombotic risk and overestimation of bleeding risk were major determinants of oral anticoagulant underuse which suggests a generalised fear of oral anticoagulants in frailer patients despite their greater stroke risk.

They stated: ‘The fear for oral anticoagulant use in frailer patients was confirmed in our analysis, with lower use with more severe heart failure.

‘We also reported older age being considered as an independent predictor of oral anticoagulant non-use although stroke risk is much higher in the elderly than in the general population.’

The authors concluded: ‘Patients with AF and concomitant heart failure do not receive oral anticoagulants on rational grounds. Bleeding risk inappropriately affects decision-making more than stroke risk.’

Dr Peter Savill

Savarese G, Sartipy U, Friberg L et al. Reasons for and consequences of oral anticoagulant underuse in atrial fibrillation with heart failure. Heart Epub ahead of print: 25 January 2018. doi: 10.1136/heartjnl-2017-312720