Outcomes for Older Patients Taking Anti-Platelet Therapy Presenting to the Emergency Department with Injury
Abstract
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.
Comments
Poster
Hi, really great poster! Do you have a feel for whether you think APA would result in more likelihood of bleeding given a large enough sample size? My assumption prior to reading your poster would be definitely yes but you mention similar clotting profiles amongst both arms of the data set?
Also do you think that if GI bleeding was taken into account that your results might change?
Reply
Thank you for your questions, Overall, I think APA may result in increased bleed rates if the sample size were larger, as you mention. As part of this prospective study, we took an additional 20ml research sample of blood from each patient to allow for detailed comparisons of how APA affects platelet aggregation in response to different agonists such as adenosine diphosphate (ADP) or arachidonic acid (AA). This has not been presented as the analysis had not been completed by the abstract submission deadline unfortunately, but we have some interesting results which should be released this year. This is why the study was prospective, although it could have been a larger retrospective study looking purely at clinical outcomes. I am not familiar with the GI bleeding group, but this could be investigated both retrospectively and prospectively. Thank you.
well done
well done
Thank you
Thank you for reviewing the poster.
Head injury/ anticoagulants/ antiplarelets
Great poster!
I wonder what you think about patients with falls and AF , At what frequency of falls we should not offer them anticoagulants or even anti platelets .
Is any aniplatelet more involved in high bleeding risk than other? Sorry if your work did not cover this question.
Thank you
Reply
Thank you for reviewing the poster and for your interesting questions. The decision-making around anti-platelets/anti-coagulants is very interesting and tricky — particularly understanding how patients are counselled and what timing would be appropriate to re-discuss this with patients following APA or anticoagulant effects. Complex, for sure.
Of those taking an APA in our study, 31 took aspirin (ASA) alone, 25 took clopidogrel (clopi) alone, and two received dual APA (ASA + clopi, n = 1; ASA + ticagrelor, n = 1). However, the numbers are too small to draw meaningful statistical inferences. Thank you.
Very interesting
Nice piece of work. What was the spread of aspirin vs clopidogrel/prasugrel/ticagrelol?
Reply
Thank you for question. Of those taking an APA in our study, 31 took aspirin (ASA) alone, 25 took clopidogrel (clopi) alone, and two received dual APA (ASA + clopi, n = 1; ASA + ticagrelor, n = 1). However, the numbers are too small to draw meaningful statistical inferences. Thank you.