OC 53.1 - Risk factors for Major Bleeding in Patients Anticoagulated with Factor Xa Inhibitors (FXai): An English Observational Study in the UK Clinical setting (AXIOM UK)

Tuesday, June 25, 2024

09:30 – 09:45 ICT

Room: Ballroom B3

Presenting Author(s)

Alexander Cohen, MSc, MD, FRACP, FESC, FRCP

Consultant Vascular Physician
Guy's and St Thomas' Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom

Co-Author(s)

CE

Chaozer Er

Consultant Physician
Woodlands Health, Singapore
Singapore, Singapore
JM

Jil Billy Mamza

Real World Evidence Lead
AstraZeneca, Medical and Scientific Affairs, Biopharmaceuticals Medical, London, UK
London, England, United Kingdom
GH

Gao He

Real World Evidence Manager
AstraZeneca, Medical and Scientific Affairs, Biopharmaceuticals Medical, London, UK
London, England, United Kingdom
KH

Kamran Hussain

Medical Affairs Manager
AstraZeneca, Medical and Scientific Affairs, Biopharmaceuticals Medical, London, UK
London, England, United Kingdom
NS

Nikki Stamp

Medical Affairs Lead
AstraZeneca, Medical and Scientific Affairs, Biopharmaceuticals Medical, London UK
London, England, United Kingdom
SC

Satarupa Choudhuri

Consultant Haematologist
The Northern Care Alliance NHS Foundation, Manchester, UK
Manchester, England, United Kingdom

Background: Many studies investigating risk factors for bleeding in anticoagulated patients were based on vitamin K antagonist therapy and defined major bleeding (MB) as bleeding-related hospitalisations, rather than the International Society on Thrombosis and Haemostasis (ISTH) definition of MB. In many countries anticoagulation with Factor Xa inhibitors (FXai) (e.g rivaroxaban and apixaban) are dominant therapies.

Aims: To describe independent risk factors for -ISTH-defined incident MB in England following the initial use of FXai (low-molecular-weight heparin or direct oral anticoagulants).

Methods: A retrospective observational cohort analysis of new users of FXai, with therapeutic indications such as atrial fibrillation (AF), venous thromboembolism (VTE), and/or non-mechanical cardiac-valve replacement, and/or adult congenital heart disease (ACHD) were included. MB was defined by ISTH criteria. Sub-distribution hazard ratios (sHR) with 95% confidence intervals (CI) were estimated from Fine and Gray regression models accounting for competing risks.

Results: There were 240,357 new users of FXai; average age 71 years, 56% male, average BMI 29 kg/m2 and 88% of patients used an oral FXai. The most common indication was AF, followed by VTE, non-mechanical cardiac valve replacement and ACHD. There were 3,873 ISTH-defined MB. We recognised 44 significant independent variables associated with MB; 40 associated with increased risk and 4 with deceased risk of MB (Table). The 8 strongest risk factors with sHR >2 were major trauma (14.8), peptic ulcer disease (5.7), oral contraceptives (3.7), urolithiasis (2.5), minor trauma (2.40), portal hypertension (2.3), history of recent major bleeding (2.3) and age ≥80 (2.2).

Conclusion(s): These 44 factors should help identify anticoagulated patients at risk of MB. Many new factors such as ethnicity, antidepressants, dementia, hormonal therapy and nephrolithiasis are described. Awareness of these factors could reduce the impact of bleeding by facilitating risk mitigation and assist in determining anticoagulation treatment intensity and duration.