A Phase 2 interventional study of Rivaroxaban 10mg and acetylsalicylic acid (ASA) 81mg Oral Tablet in Hip Fractures, sponsored by University of Calgary. Recruiting at 3 sites in Canada. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2025-01-14.
Sponsored by University of Calgary · Phase 2, Interventional, and Treatment
As our Canadian population ages, hip fractures in these older adults are becoming very common. The best treatment for the majority of these injuries is urgent treatment with surgery. However, the hip fracture itself, the surgery required, and the immobility following these injuries are all risk factors for developing blood clots in the legs (deep vein thrombosis or DVT) and blood clots in the lungs (pulmonary embolism or PE). These complications are a common cause of death in patients with hip fractures and often result in prolonged medical treatment and hospital stays.
Patients with hip fractures who require surgery are traditionally given injectable blood thinners to help prevent blood clots; however, these medications are costly, may not be tolerated well, and can be difficult to take, as prescribed. Oral blood thinning medications are being used more commonly, but it is unknown which of these medications is the most effective in preventing blood clots in patients after a hip fracture.
Thrombelastography (TEG) technology uses a small sample of blood to evaluate a person's clotting ability. Our research has used TEG technology to evaluate blood clotting risk after hip fracture surgery and the investigators have found that platelets may play an important role in abnormal blood clotting after a hip fracture. The investigators have also shown that acetylsalicylic acid (ASA or Aspirin) may help reduce the abnormal platelet hyperactivity associated with blood clotting. This medication warrants investigation for blood clot prevention after hip fracture.
The investigators propose to directly compare different oral medication regimens after hip fracture surgery, in order to determine which is safest and most effective in preventing blood clots. Our multi-disciplinary research team includes physicians, surgeons, and scientists with experience evaluating different medications for blood clot prevention. Our results will help determine the best medical treatment for preventing DVT and PE, which will benefit patients with hip fractures worldwide.
Background:
With over 30,000 hip fractures in Canada annually, these injuries are an epidemic. Venous thromboembolism (VTE) events are common following hip fracture surgery (HFS) and include life-threatening pulmonary embolism (PE; a leading cause of preventable mortality) and debilitating deep vein thromboses (DVTs; second most common complication). Thromboprophylaxis reduces VTE, but the optimal medication remains unknown.
Low molecular weight heparin (LMWH) has been the mainstay, but adherence is poor: only 1 in 5 patients adhere after HFS, limiting its effectiveness. Meta-analyses support that direct oral anticoagulants (DOACs) are as effective as LMWH in prevention of VTE, but the data are limited by borderline effect sizes, small sample sizes, and inconsistent outcomes. Our survey found that surgeons report safety concerns and are reluctant to use DOACs due to post-operative bleeding risk.
Our research demonstrates platelet-dominant hypercoagulability using serial thrombelastography (TEG), reduced platelet activity with aspirin (ASA) use, and maybe increasing comfort with prescribing ASA post-HFS. Randomized controlled trials (RCTs) comparing LMWH and ASA post-injury are limited by non-standardized therapy duration, asymptomatic DVT inclusion, and patient heterogeneity. ASA has been favourably compared to DOACs and LMWH in arthroplasty RCTs examining oral thromboprophylaxis following total hip and total knee arthroplasty. Continued morbidity and mortality, patient and surgeon preference, and our network meta-analysis support the need for comparison between DOAC and ASA for VTE prevention after HFS. Based on our research, our resent network meta-analysis supporting oral thromboprophylaxis, along with patient preference for oral medications, there is a need for comparison between DOAC and ASA for prevention of VTE to reduce the continued morbidity and mortality that ensues following HFS.
Specific Aims:
(3) Methods:
This is a multi-centre double-blind pilot trial consisting of consecutive eligible patients 50 years or older requiring HFS who will be randomized (1:1) via web-based randomization to rivaroxaban 10 mg daily for 35 days or ASA 81 mg daily for 35 days, with 90-day follow-up. The primary feasibility outcome measure is an estimate of the mean monthly recruitment rate over 12 months across participating sites, including 95% confidence intervals, with a priori feasibility criteria determining progression to the full trial. Secondary feasibility outcomes are consent and retention rates, and drug adherence.
Secondary clinical outcomes will include symptomatic VTE, major bleeding, clinically relevant non-major bleeding, and 90-day mortality (independently and blindly adjudicated). Intention-to-treat analysis will be used, and subgroup analysis will compare age, sex, gender, and surgical type. Additional patient-reported (the Cumulated Ambulation Score and Clinical Frailty Scale), value-based (direct and indirect costs) and translational (coagulation) outcomes will be included.
2,261 studies on the registry are indexed under Fractures, Bone; 325 are open to participants now.
This study's planned enrollment of 250 is above the median of 69 across 1,482 interventional studies indexed under Fractures, Bone.
Browse Fractures, Bone studies →University of Calgary is the lead sponsor of 686 studies on the registry; 189 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 2 (20%) have results posted.
Counted across the registry records on this site, refreshed daily.
Patients aged 50 years or older with an acute hip fracture (presentation to hospital within 24 hours of injury) that requires surgical treatment will be approached for inclusion in the study:
Exclusion Criteria:
Rivaroxaban 10mg daily for 35 days post hip fracture surgery
Drug: Rivaroxaban 10mg
acetylsalicylic acid (ASA) 81mg daily for 35 days post hip fracture surgery
Drug: acetylsalicylic acid (ASA) 81mg Oral Tablet
Rivaroxaban 10mg daily for 35 days post hip fracture surgery
Also known as: Rivaroxaban
acetylsalicylic acid (ASA) 81mg daily for 35 days post hip fracture surgery
Also known as: Aspirin
Recruitment Rate
Mean number of participants recruited per centre per month, calculated based on the total recruitment
Time frame: 12 months
Treatment fidelity
Adherence to study medication and pilot trial protocol
Time frame: 12 months
Retention rate
Participant completion of the pilot trial protocol
Time frame: 12 months
Consent rates
Consent rates for eligible participants who are approached, including reasons for non-consent
Time frame: 12 months
Trial implementation barriers Questionnaire
Trial implementation barriers will be assessed using an implementation barrier questionnaire developed for this study. The questionnaire will include questions about barriers and challenges related to the following: data capture, study management, study team infrastructure, participant-specific, site-specific, intervention, and study design. The implementation barriers will be summarized at the end of the study.
Time frame: 12 months
Healthcare cost
Direct and indirect healthcare costs including number of hospital admissions, and number of visits to healthcare providers.
Time frame: 12 months
Venous thromboembolism events
Number of venous thromboembolism events
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge, 2-week, 4-week, 6-week, 12-week
Arterial thromboembolism events
Number of arterial thromboembolism events
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge, 2-week, 4-week, 6-week, 12-week
Bleeding complications
Major bleeding, clinically relevant non-major bleeding
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge, 2-week, 4-week, 6-week, 12-week
Mortality
Mortality within 90 days after hip fracture surgery
Time frame: 90 days
Frailty
Frailty is measured by Clinical Frailty Scale. A valid tool for evaluating these patients' frailty levels. The score ranges from 1 to 9. The higher scores mean better frailty (worse outcome).
Time frame: Baseline
Complete Blood Counts
Complete Blood Counts
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge
Partial thromboplastin time
Partial thromboplastin time
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge
activated partial thromboplastin time
activated partial thromboplastin time
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge
Cumulated Ambulation Score
A valid tool for evaluating these patients' basic mobility. The score ranges from 0 to 6. The higher scores mean better mobility.
Time frame: Baseline and 2 weeks follow up
Study Medication Adherence
Adherence to study medications
Time frame: Baseline, Post-operative day 1, Post-operative day 2, Post-operative day 3, Post-operative day 4, Post-operative day 5, Post-operative day 6, or until hospital discharge, 2-week, 4-week, 6-week, 12-week
Plan to share: No
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