Outcomes for Older Patients Taking Anti-Platelet Therapy Presenting to the Emergency Department with Injury

Title: Outcomes for Older Patients Taking Anti-Platelet Therapy Presenting to the Emergency Department with Injury: A Prospective Observational Cohort Study

Abstract

Introduction

Older patients taking anti-platelet agents (APA) frequently present to the emergency department with injury. In the UK, almost half of patients admitted following injury are aged ≥65 years, and anti-platelet therapy is used in approximately 40% of older adults. The clinical impact of APA use on bleeding outcomes remains uncertain, with conflicting evidence and limited prospective data.

Methods

We conducted a prospective observational cohort study at Oxford University Hospitals NHS Foundation Trust between 8 February 2024 and 23 July 2025. Consecutive patients aged ≥65 years presenting within 24 hours of injury were recruited. Patients taking one or more APA at the time of injury were compared with contemporaneous patients not taking anti-platelet therapy. Patients receiving anticoagulants, non-steroidal anti-inflammatory drugs, those with inherited bleeding disorders, or inter-hospital transfers were excluded. The primary outcome was clinically relevant bleeding (major and non-major), defined according to International Society on Thrombosis and Haemostasis criteria.

Results

One hundred and ten patients were enrolled (58 taking APA; 51 not taking APA). Injury severity score (ISS) was low in both groups (median ISS 1 [IQR 1–2]). Clinically relevant major bleeding occurred in 10/58 (17.2%) APA-treated patients and 5/52 (9.6%) non-APA patients, with no statistically significant difference between groups (p=0.28). Among patients with clinically relevant major bleeding, intracranial haemorrhage accounted for most events in both groups and was more frequent among those taking APA (7/10 vs 2/5), although numbers were small and no formal comparison was performed. Clinically relevant non-major bleeding occurred in 8/58 (13.8%) and 8/52 (15.4%), respectively (p=1.00). Admission physiology was similar: median systolic blood pressure 145 (IQR 129–160) vs 150 (IQR 132–165) mmHg (p=0.68) and median heart rate 79 (IQR 79–83) vs 81 (IQR 72–92) bpm (p=0.21). Routine laboratory measures, including haemoglobin, platelet count, prothrombin time, and activated partial thromboplastin time, were comparable between groups.

Conclusion

In older patients presenting with injury, anti-platelet therapy was associated with a numerically higher but not statistically significant increase in clinically relevant bleeding, despite minor injury severity and similar admission physiology and routine haemostatic parameters.