Oral Blood Thinners for Hip Fracture

(HIP PRO Pilot Trial)

Recruiting at 2 trial locations

Overseen By Jessica Duong, PhD

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: University of Calgary

Must not be taking: Blood thinners

Disqualifiers: Delayed presentation, Cancer, Bleeding disorder, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 2

Duration: 5 weeks

250 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to identify the best oral blood thinner for preventing blood clots in individuals who have undergone hip fracture surgery. It compares two medications: acetylsalicylic acid (ASA, also known as Aspirin) and Rivaroxaban (an anticoagulant). The objective is to determine which drug is safer and more effective at preventing blood clots in the legs and lungs post-surgery. Suitable candidates for this trial are those aged 50 or older with a recent hip fracture requiring surgery. As a Phase 2 trial, the research focuses on assessing the treatment's effectiveness in an initial, smaller group of participants.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it does exclude patients who have been on certain blood thinners like Warfarin, DOACs, or chronic aspirin use in the three months before the hip fracture. It's best to discuss your current medications with the trial team to see if they affect your eligibility.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that both Rivaroxaban and Aspirin (ASA) have been studied for safety in treating blood clots after hip fractures.

Studies found Rivaroxaban effective in preventing blood clots in veins after hip surgery, though it carries a small risk of bleeding. In one study, major blood clots were rare, occurring in only about 0.6% of patients, while about 1% experienced some type of blood clot.

Aspirin has also been used to prevent blood clots. Research indicates it can lower the risk of clots without a high risk of bleeding, though it might increase the need for blood transfusions during surgery in some cases. Overall, Aspirin has been found safe and helpful in reducing blood clot risks after surgery.

Both treatments have been used safely in other situations. This trial aims to determine which is better for preventing clots after hip fractures. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments for hip fractures because they offer new approaches to blood clot prevention after surgery. Unlike traditional treatments that often rely on higher doses of blood thinners like warfarin or heparin, acetylsalicylic acid (ASA) 81mg and rivaroxaban 10mg are being tested for their effectiveness in lower doses. ASA is well-known for its safety profile and ease of use, while rivaroxaban provides a different mechanism of action by directly inhibiting Factor Xa, a key player in blood clot formation. These treatments have the potential to reduce the risk of clots with fewer side effects and more convenience for patients.

What evidence suggests that this trial's treatments could be effective for preventing blood clots after hip fracture surgery?

This trial will compare the effectiveness of Rivaroxaban and acetylsalicylic acid (ASA) in preventing blood clots after hip fracture surgery. Research has shown that Rivaroxaban significantly lowers the risk of venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), compared to treatments like enoxaparin. One study found that only 0.57% of patients taking Rivaroxaban experienced a blood clot, compared to 1.14% with standard care.

For acetylsalicylic acid (ASA or Aspirin), another treatment option in this trial, the evidence is mixed. Some studies suggest it can help prevent blood clots in patients undergoing hip surgery, but it might not be as effective as other blood thinners. Considering the benefits and risks of each treatment option is important when deciding to join this trial. ^{3 4 5 6 7}

Who Is on the Research Team?

Prism Schneider, MD

Principal Investigator

University of Calgary

Are You a Good Fit for This Trial?

This trial is for adults aged 50 or older who have a hip fracture that needs surgery and got to the hospital within 24 hours of injury. They can be on low-dose anti-platelet therapy like aspirin. People with cancer-related fractures, those who can't follow up, took lots of blood thinners post-injury, or have certain bleeding/clotting disorders can't join.

Inclusion Criteria

I am currently taking a single anti-platelet medication.

Signed informed consent or surrogate consent to participate in study

I am 50 or older and need surgery for a hip fracture that happened within the last day.

Exclusion Criteria

I am under 50 years old.

I have been on blood thinners like Warfarin or aspirin for the last three months before my hip fracture.

I have a fracture around my hip replacement.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to receive either rivaroxaban 10 mg daily or ASA 81 mg daily for 35 days post hip fracture surgery

5 weeks

Daily medication administration

Follow-up

Participants are monitored for safety and effectiveness, including VTE and bleeding complications, with assessments at various intervals

12 weeks

2-week, 4-week, 6-week, and 12-week follow-up visits

Long-term Follow-up

Participants are monitored for mortality and healthcare costs over a 12-month period

12 months

What Are the Treatments Tested in This Trial?

Interventions

• Acetylsalicylic acid (ASA) 81mg Oral Tablet
• Rivaroxaban 10mg

Trial Overview The study compares oral blood thinners Rivaroxaban (10mg) and ASA (81mg) in preventing blood clots after hip fracture surgery. It aims to find out which one is safer and more effective using TEG technology to monitor clotting ability.

How Is the Trial Designed?

Group I: acetylsalicylic acid (ASA) 81mg daily Experimental Treatment 1 Intervention

acetylsalicylic acid (ASA) 81mg daily for 35 days post hip fracture surgery

Group II: Rivaroxaban 10mg Experimental Treatment 1 Intervention

Rivaroxaban 10mg daily for 35 days post hip fracture surgery

Who Is Running the Clinical Trial?

University of Calgary

Lead Sponsor

Trials

827

Recruited

902,000+

Canadian Institutes of Health Research (CIHR)

Collaborator

Trials

1,417

Recruited

26,550,000+

Published Research Related to This Trial

In a study of 479 patients undergoing hip or knee arthroplasty, rivaroxaban, used after enoxaparin for VTE prevention, showed zero cases of symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), death, stroke, or myocardial infarction during treatment, indicating high efficacy and safety.

The modified thromboprophylaxis regimen resulted in only one major bleeding episode (0.2%) and nine non-major bleeding episodes (1.9%), suggesting that this approach minimizes bleeding risks while effectively preventing VTE.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy and safety of rivaroxaban thromboprophylaxis after arthroplasty of the hip or knee: retrospective cohort study. Loganathan, V., Hua, A., Patel, S., et al.[2023]

In a study of 32 patients undergoing total knee arthroplasty, both aspirin (300 mg) and rivaroxaban (10 mg) were found to be equally effective in preventing venous thromboembolism (VTE) without significant differences in complications or outcomes.

There were no notable differences in safety profiles or side effects between the two medications, suggesting that both can be safely used for VTE prevention after knee surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Venous thromboembolism prophylaxis after total knee arthroplasty (TKA): aspirin vs. rivaroxaban. Colleoni, JL., Ribeiro, FN., Mos, PAC., et al.[2022]

In a study of 766 patients undergoing joint arthroplasty, no major bleeding events were associated with the use of rivaroxaban for thromboprophylaxis when combined with peripheral nerve blocks.

While some minor bleeding occurred, particularly at the surgical site after starting rivaroxaban, the overall data suggests that using nerve blocks in conjunction with rivaroxaban does not increase the risk of major bleeding.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Combination of Superficial and Deep Blocks with Rivaroxaban. Chelly, JE., Metais, B., Schilling, D., et al.[2015]

Rivaroxaban (Xarelto) is a highly effective oral anticoagulant that significantly reduces the risk of venous thromboembolism after hip or knee replacement surgery, outperforming subcutaneous enoxaparin without increasing major bleeding risks, based on data from four large clinical trials (RECORD).

This medication is user-friendly, requiring only one 10 mg tablet per day and eliminating the need for regular blood monitoring or dose adjustments, making it a convenient alternative to traditional anticoagulants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Rivaroxaban (Xarelto): new anticoagulant inhibitor of factor Xa]. Scheen, AJ.[2015]

A systematic review of 5 studies involving 5179 patients suggested that aspirin (ASA) may lower the risk of post-operative arterial thrombosis (AT) compared to anticoagulants, but this finding was not statistically significant.

Conversely, aspirin treatment was associated with a higher tendency for post-operative venous thromboembolism (VTE) compared to anticoagulants, indicating a potential risk that needs further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A systematic review on the effect of aspirin in the prevention of post-operative arterial thrombosis in patients undergoing total hip and total knee arthroplasty. Lussana, F., Squizzato, A., Permunian, ET., et al.[2018]

In a comparison of prophylactic regimens for joint replacement surgery from the ORTHO-TEP registry, rivaroxaban demonstrated superior efficacy and fewer side effects compared to low-molecular-weight heparin.

The study's findings align with previous randomized trials, emphasizing the importance of including consecutive patients in the registry to enhance the generalizability of the results.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-molecular-weight heparin versus rivaroxaban in orthopedic surgery. Bergqvist, D.[2013]

Rivaroxaban has been shown to be more effective than enoxaparin in preventing venous thromboembolism (VTE) in orthopedic patients, based on a comprehensive study involving 12,729 patients in the RECORD program.

The safety profile of rivaroxaban is excellent, with no significant increase in major bleeding events compared to enoxaparin, making it a promising option for VTE prophylaxis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Therapeutic potential of rivaroxaban in the prevention of venous thromboembolism following hip and knee replacement surgery: a review of clinical trial data. Kwong, LM.[2022]

In a study of 40 patients undergoing total knee arthroplasty, both aspirin (300 mg/day) and rivaroxaban (10 mg/day) were found to be equally effective in preventing venous thromboembolism (VTE), with no cases of deep vein thrombosis or pulmonary embolism reported.

Both medications were safe, showing no significant increase in wound complications or bleeding, indicating that either could be a suitable option for VTE prophylaxis after knee surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Aspirin versus Rivaroxaban to Prevent Venous Thromboembolism after Total Knee Arthroplasty: A Double-blinded, Randomized Controlled Trial. Hongnaparak, T., Janejaturanon, J., Iamthanaporn, K., et al.[2022]

In a study of 390 patients after hip fracture surgery, extended prophylaxis with aspirin for 21 days was found to be as effective as rivaroxaban in preventing venous thromboembolism (VTE), with VTE rates of 6.6% for aspirin and 5.7% for rivaroxaban, showing no significant difference (P=0.83).

Both aspirin and rivaroxaban had low rates of major bleeding complications, with 1.0% in the aspirin group and 0.5% in the rivaroxaban group, indicating that aspirin is a safe and effective alternative for extended thromboprophylaxis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the Efficacy and Safety of Aspirin and Rivaroxaban Following Enoxaparin Treatment for Prevention of Venous Thromboembolism after Hip Fracture Surgery. Huang, Q., Xing, SX., Zeng, Y., et al.[2023]

Rivaroxaban, a new oral antithrombotic drug, effectively inhibits thrombin generation and shows a predictable pharmacokinetic profile, making it well tolerated in patients.

In clinical studies involving patients undergoing total hip or knee surgery, rivaroxaban demonstrated superior antithrombotic efficacy compared to enoxaparin, with comparable safety and no adverse effects on liver function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rivaroxaban, a new, oral, direct factor Xa inhibitor for thromboprophylaxis after major joint arthroplasty. Borris, LC.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10589573/

The efficacy and safety of aspirin in preventing venous ... Our updated meta-analysis showed that aspirin was inferior to when compared with other anticoagulants in VTE-related orthopedic major surgery.

2. nature.com nature.com/articles/s41598-025-88493-4

Effectiveness of aspirin in preventing deep vein thrombosis ... Aspirin is an effective prophylaxis for venous thromboembolism in ambulatory patients with femoral neck fracture undergoing hip arthroplasty.

3. cda-amc.ca cda-amc.ca/sites/default/files/pdf/htis/2020/RC1304%20ASA%20for%20VTE%20Final.pdf

Acetylsalicylic Acid for Venous Thromboembolism ... The results of meta-analysis of nine RCTs in one SR14 showed that there was no significant difference in the risk of PE between patients ...

4. scholars.uthscsa.edu scholars.uthscsa.edu/en/publications/aspirin-in-prevention-of-venous-thromboembolism-following-hip-fra/

Aspirin in prevention of venous thromboembolism following ... The purpose of this study is to assess the effectiveness of aspirin to other agents in preventing VTE and mortality following hip fracture surgery.

5. academic.oup.com academic.oup.com/eurheartjsupp/article/26/Supplement_1/i102/7646229

Prevention of thromboembolism after a fracture: is aspirin ... Estimates suggest the occurrence of fatal PE in hospitalized patients between 0.1% and 0.8% after elective general surgery, up to 3% after ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7044955/

Aspirin and fracture risk: a systematic review ... Aspirin use was associated with a 17% lower odds for any fracture (OR 0.83, 95% CI 0.70 to 0.99; I2=71%; six studies; n=511 390). Aspirin was ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S088354032301135X

Safety of Early Surgery in Hip Fracture Patients Taking ... Aspirin has been considered a risk factor for increased blood loss and blood transfusion requirements in hip fracture surgery in some previous studies [37,45], ...