Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The prevalence in the UK is 3.3%. Atrial fibrillation leads to an increased risk of stroke. Treatment with anticoagulants substantially reduces risk of stroke but are also associated with an increased risk of bleeding and especially intracranial haemorrhages which are the most feared complication. There are two classes of anticoagulant treatments : (i) vitamin K antagonist (VKA) and (ii) non-vitamin K antagonist oral anticoagulant (NOAC). Anticoagulant treatments are recommended in most patients at risk of strokes except in those with low risk of strokes. Despite this evidence, underuse or premature termination of anticoagulant treatments is still common. The risk of falls or actual falls are the most common reasons for discontinuing anticoagulants.
Our research aims are to evaluate whether the risk of stroke should outweigh the risk of bleeding in atrial fibrillation patients that are at risk of falls or that experienced a fall, in a UK setting
The objective of this retrospective longitudinal cohort study is primarily designed to determine safety and efficacy of anticoagulants (Vitamin-K antagonist (VKA), non-vitamin K antagonist oral anticoagulant (NOAC), anti-platelet and no treatment) in atrial fibrillation patients who are at risk of falls or with history of falls. The primary safety outcome will be major bleeding and the primary efficacy outcome will be ischaemic stroke/systemic embolism .
Patients with a diagnosis of atrial fibrillation (in Clinical Practice Research Datalink or Hospital Episode Statistics) between January 2006 and December 2020 will be selected. They will be further defined at risk of falls or with history of falls according to the Steffel et al. 2016 study. The main exposure variable will be the type of anticoagulation treatment (VKA, NOAC, antiplatelet, no anticoagulation treatment). Analyses will be both descriptive and comparative. Cox regression models will be used to adjust for confounding, the exposure will be treated as a time varying covariate.
This intended public health benefit will be that based on this study, the most appropriate anticoagulant treatment for patients suffering from atrial fibrillation and at-risk of falls or with history of falls will be identified. There is currently a lack of evidence and guidance (from the international atrial fibrillation guidelines) on what is the most appropriate treatment for these patients. It will provide clear guidance to physicians, providers, and health policy makers, and ultimately for the benefits of the patients and the healthcare system. Prescribing the most appropriate anticoagulant treatment may improve safety (less bleeding events) and improve efficacy (less stroke). These improvement may also translate into economic savings for the healthcare system.
Ischemic stroke, haemorrhagic stroke, systemic embolism, ischemic stroke/systemic embolism, major bleeding, intracranial haemorrhage, myocardial infarction, cardiovascular mortality, extracranial bleeding, net clinical benefit, number needed to treat for net effect (NNTnet)
Thibaut Galvain - Chief Investigator - Johnson & Johnson Medical SAS
Thibaut Galvain - Corresponding Applicant - Johnson & Johnson Medical SAS
Gabriela Czanner - Collaborator - Liverpool John Moores University
Gregory Lip - Collaborator - University of Liverpool
SARAH DONEGAN - Collaborator - University of Liverpool
HES Admitted Patient Care;ONS Death Registration Data