Patients with paroxysmal atrial fibrillation (AF) eligible for anticoagulation are still less likely to receive anticoagulants than those with persistent or permanent AF, a UK study has found.¹

Both national and European guidelines recommend that anticoagulants are offered to all patients with AF at increased risk of stroke, irrespective of the type of AF.

The use of scoring systems such as CHADS₂ and CHA₂DS₂-VASc along with the availability of novel anticoagulant drugs has, to a degree, simplified the approach to anticoagulation in AF. As a result more patients at risk of thromboembolic events should now be receiving the correct evidence-based treatment, namely anticoagulation. 

Researchers from the University of Birmingham set out to investigate whether patients in the UK with paroxysmal AF were less likely to be treated with anticoagulants than those with persistent or permanent AF and to examine trends in treatment between 2000 and 2015.1 They performed 16 sequential cross-sectional analyses on data from 648 practices contributing to The Health Improvement Network database for this period. All patients with a diagnosis of AF aged ≥ 35 years and registered for at least a year were included in the study. The outcome was treatment with anticoagulants.

The proportion of patients with AF who had a diagnosis of paroxysmal AF increased from 7.4% (95% CI: 7.0-7.8%) in 2000 to 14.0% (95% CI: 13.7-14.3%) in 2015. Among patients with a CHADS2 score ≥ 1, between 2000 and 2015 the proportion prescribed anticoagulants increased from 18.8% (95% CI: 16.4-21.4%) to 56.2% (95% CI: 55.0-57.3%) in patients with paroxysmal AF and from 34.2% (95% CI: 33.3-35.0%) to 69.4% (95% CI: 68.9-69.8%) in patients with persistent/permanent AF.

The relative risk (RR) for the treatment of patients with paroxysmal AF compared with patients with persistent/permanent AF increased from RR 0.48 (95% CI: 0.42-0.55) to RR 0.76 (95% CI: 0.74-0.77). Adjusting for age, sex and the presence or absence of contraindications had little effect on the results.

In the year 2000, eligible patients with paroxysmal AF were half as likely to be treated with anticoagulants as patients with persistent or permanent AF. This rather startling statistic has improved to some degree over time but even in 2015 patients with paroxysmal AF eligible for anticoagulation were still almost 20% less likely to have these drugs prescribed than those patients with persistent or permanent AF.

The study authors conclude: ‘Patients with paroxysmal AF are less likely to be treated with anticoagulants than patients with persistent or permanent AF. This difference is not explained by differences in patient demographics, stroke risk or contraindications.’

They state: ‘ESC guideline-adherent antithrombotic management is associated with significantly better outcomes, including those related to mortality, thromboembolism, stroke and TIA.

‘Current treatment practice does not appear to closely follow published treatment guidelines, which most likely results in elevated levels of preventable ischaemic stroke among patients with paroxysmal AF, even more so than in the wider AF population, leading to greater morbidity, mortality and overall cost to healthcare systems.’

They add that further research is needed to establish whether the difference in treatment between patients with paroxysmal AF and those with other types of AF is the result of lower levels of treatment initiation or whether patients with paroxysmal AF are more likely to stop their treatment.

Clearly although things are improving there is still some way to go to ensure that patients with paroxysmal AF are appropriately anticoagulated and thus benefit from the corresponding reduction in risk of thromboembolic disease.