Non-valvular atrial fibrillation (NVAF) is a heart rhythm disturbance which increases the risk of adverse outcomes such as strokes. Treatment with oral anticoagulant drugs (OAC) such as warfarin may reduce this risk in individuals with NVAF, however these drugs also increase the risk of bleeding. Guidelines on therapeutic management after a NVAF diagnosis are therefore based on a balance between the benefits (stroke prevention) and risks (bleeding) of treatment. If an individual with NVAF suffers a first bleed while on OAC treatment, the balance between benefits and risks may be altered therefore prescribers must re-evaluate their treatment decisions; there is a lack of evidence and guidelines to inform these decisions in this situation.
The study will identify individuals with NVAF, suffering a first bleed on OACs and follow them to identify what treatment decisions are made in the 6 months following the bleed and identify whether certain treatment decisions are made for certain types of individual. The study will then compare the frequency of adverse outcomes occurring while under each treatment. The information generated by this study will help to inform treatment decisions in individuals with NVAF after their first bleed and could lead to the development of treatment guidelines.
The objective of this study is to generate evidence on drug utilisation choices for individuals with NVAF following a first clinically relevant bleed while on an oral anticoagulant (OAC), and to determine the association between therapeutic choices and subsequent adverse patient outcomes. The study will use a retrospective cohort design and utilise CPRD and linked HES data. The population will be stratified according to the availability of novel oral anticoagulants (NOACs) in England and, in the period during which NOACs are available, in terms of the specific OAC used at the time of the first bleed. In each of the stratified populations, drug utilisation in the 6 months following the first bleed will be described in terms of restarting, switching and discontinuing treatment. In the period prior to NOAC availability, the association between patient characteristics and different drug utilisation choices will be explored using multivariate logistic regression and the association between drug utilisation following the first bleed and adverse patient outcomes (bleeding, stroke, thromboembolic events, death) will be explored using Cox regression, adjusting for differences in underlying patient characteristics.
Clinically relevant bleeding • Death • Stroke • Thromboembolic events
Sreeram Ramagopalan - Chief Investigator - London School Of Economics & Political Science
Cormac Sammon - Corresponding Applicant - PHMR Associates Limited ( UK )
Alexander Cohen - Collaborator - King's College London (KCL)
Caritey Benoît-Damien - Collaborator - Bristol-Myers Squibb Pharmaceuticals Limited - UK ( BMS )
Cinira Lefevre - Collaborator - Bristol Myers Squibb - Europe ( BMS )
Donna Fountain - Collaborator - PHMR Associates Limited ( UK )
Gillian Stynes - Collaborator - Bristol-Myers Squibb Pharmaceuticals Limited - UK ( BMS )
Matthew Lumley - Collaborator - Pfizer Ltd - UK
Mihail Samnaliev - Collaborator - PHMR Associates Limited ( UK )
Nathan Hill - Collaborator - Bristol-Myers Squibb Pharmaceuticals Limited - UK ( BMS )
Sharada Weir - Collaborator - Maverex Ltd
HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation