Hospitalized patients with atrial fibrillation compared to those included in recent trials on novel oral anticoagulants: a population-based study

Abstract

Background: Nonvalvular atrial fibrillation is associated with a substantial risk of stroke. Novel oral anticoagulants (NOACs) with predictable anticoagulant effect and no need for routine coagulation monitoring have recently shown good results when compared with warfarin in phase III clinical trials.

Objective: To describe clinical features and pharmacological treatments of a population-based cohort of patients with nonvalvular atrial fibrillation and ascertain whether they are comparable with those included in the three main phase III clinical trials on NOACs.

Results: Of the 2,862,264 subjects considered for this study 13,360 patients (0.47%) were recently discharged from the hospital with a diagnosis of nonvalvular atrial fibrillation. Mean age was 76.3 (SD 10.7), 49.8% were men and 64.6% were ≥75 years of age. 50% of patients were treated with warfarin and 44.1% with antiplatelet agents. The proportion of patients on antiplatelet therapy increased with age up to a rate of 54.3% in subjects ≥85 years. 92.9% of the studied cohort was on polypharmacy (mean 8 drugs/patient). Around 20% of the entire cohort was treated with amiodarone, a drug potentially interfering with NOACs, and 3.6% from a subgroup analysis had renal failure, which is an exclusion criterion in trials on NOACs.

Conclusion: In patients recently discharged from the hospital with the diagnosis of nonvalvular AF, warfarin use decreases and aspirin treatment increases with patients' age. These patients are older, more frequently female, and on multiple medications. The benefit of NOACs in these subjects needs to be confirmed in phase IV clinical studies.