Heparin for Hand Amputation

Overseen By Linda M Zhu

Age: Any Age

Sex: Any

Trial Phase: Phase 4

Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Must not be taking: Anticoagulants

Disqualifiers: Coagulopathy, Acute ulcers, Shock, 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

Approved in 5 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 5 days

What You Need to Know Before You Apply

What is the purpose of this trial?

This clinical trial tests whether intravenous heparin, a blood thinner, improves the success of reattaching fingers or parts of the hand after traumatic amputation. Researchers aim to determine if heparin leads to better outcomes compared to standard care without it. The trial will also examine possible side effects, such as bleeding or bruising. Individuals who have experienced such an amputation and are not on certain blood-thinning medications might be suitable candidates for this study. As a Phase 4 trial, this research seeks to understand how this FDA-approved and effective treatment benefits more patients.

Will I have to stop taking my current medications?

If you are taking anticoagulants (blood thinners) like Coumadin, Eliquis, Pradaxa, or Plavix, you cannot participate in this trial. The protocol does not specify about other medications, so it's best to discuss with the trial team.

What is the safety track record for intravenous unfractionated heparin?

Research has shown that intravenous unfractionated heparin is generally well-tolerated for preventing blood clots. Studies have found it to be as effective and safe as other treatments for conditions like pulmonary embolism, a blockage in the lungs. However, like any medication, it can have side effects.

The most common side effects of heparin include bleeding, a low number of blood cells called platelets (thrombocytopenia), and thinning of the bones (osteopenia). Patients receiving heparin should be monitored for these side effects, especially bleeding. Intravenous unfractionated heparin is widely used in hospitals and is approved for other conditions, which provides reassurance about its safety. ^{1 2 3 4 5}

Why are researchers enthusiastic about this study treatment?

Researchers are excited about using intravenous unfractionated heparin for hand amputation because it offers a potentially more precise anticoagulation method compared to the standard subcutaneous heparin injections. Unlike the standard regimen, this treatment tailors the dosage based on the patient's blood clotting response, aiming for a specific activated partial thromboplastin time (APTT). This targeted approach might improve blood flow and healing after surgery, which could be crucial for the success of reattaching a hand.

What evidence suggests that intravenous unfractionated heparin is effective for improving replantation success in traumatic digital amputation?

Research has shown that intravenous unfractionated heparin, which participants in this trial may receive, has been effectively used for many years to prevent blood clots. One study demonstrated that heparin increased the success rate of reattaching or repairing severed fingers. Maintaining blood flow in reattached fingers is crucial for their survival. Although some studies suggest that other types of heparin might slightly outperform in preventing blood clots, unfractionated heparin remains a well-known choice. In summary, strong evidence supports its use in improving outcomes for procedures like finger reattachment. ^{1 2 6 7 8}

Who Is on the Research Team?

Bruno Mastropasqua, MD FRCSC

Principal Investigator

Université de Montréal

Are You a Good Fit for This Trial?

This trial is for individuals who have undergone hand replantation or revascularization at the Centre hospitalier de l'Université de Montréal. It's not for those with amputations above the wrist, on certain blood thinners, with degloving injuries, or conditions that make heparin use unsafe like bleeding disorders and severe liver damage.

Inclusion Criteria

All replantation and revascularization patients who are accepted into the CEVARMU program at the Centre hospitalier de l'Université de Montréal

Exclusion Criteria

I cannot take heparin due to a health condition like bleeding disorders or severe liver damage.

I am taking blood thinners other than aspirin.

I have had an amputation above my wrist.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants receive intravenous unfractionated heparin or sham comparator for 5 days following digital replantation/revascularization

5 days

Daily monitoring for dosage adjustments

Follow-up

Participants are monitored for replantation/revascularization success and heparin-related complications

Up to 14 days

Regular in-person assessments

What Are the Treatments Tested in This Trial?

Interventions

• Intravenous unfractionated heparin
• Sham

Trial Overview The study tests if intravenous unfractionated heparin improves the success of surgically reattached fingers after trauma. Participants are divided into two groups: one receiving a therapeutic dose of heparin and another without it to compare outcomes at discharge.

How Is the Trial Designed?

Group I: Intravenous unfractionated heparin Experimental Treatment 1 Intervention

Administration of intravenous unfractionated heparin according to the Centre hospitalier de l'Université de Montréal (CHUM) deep vein thrombosis (DVT) protocol for 5 days after vascular anastomosis. A bolus will be administered intraoperatively based on the patient's weight. Dosages will be adjusted according to the activated partial thromboplastin time (aim for an APTT of 50-70), which will be measured 6 hours after the start of the protocol and after every dosage adjustment or every morning at 6 a.m. if no adjustments were made in the last 6 hours.

Group II: Control Placebo Group 1 Intervention

No administration of intravenous unfractionated heparin. These patients receive 5000 IU BID of heparin subcutaneously, as a standard post-operative protocol for all in-patients. The control group receives sham bolus intraoperatively of normal saline and a post-operative normal saline infusion at a fixed dose through an infusion pump to mimic IV heparin infusion.

Intravenous unfractionated heparin is already approved in European Union, United States, Canada, Japan, China for the following indications:

Approved in European Union as Heparin Sodium for:

• Prevention of thromboembolic disorders
• Treatment of deep vein thrombosis
• Treatment of pulmonary embolism
• Prevention of clotting in extracorporeal circulation during cardiac surgery

Approved in United States as Heparin Sodium for:

• Prevention and treatment of deep vein thrombosis and pulmonary embolism
• Prevention of clotting in extracorporeal circulation during cardiac surgery
• Anticoagulant therapy in acute and chronic consumption coagulopathies

Approved in Canada as Heparin Sodium for:

• Prevention and treatment of thromboembolic disorders
• Prevention of clotting in extracorporeal circulation during cardiac surgery

Approved in Japan as Heparin Sodium for:

• Prevention and treatment of deep vein thrombosis and pulmonary embolism
• Prevention of clotting in extracorporeal circulation during cardiac surgery

Approved in China as Heparin Sodium for:

• Prevention and treatment of thromboembolic disorders
• Prevention of clotting in extracorporeal circulation during cardiac surgery

Who Is Running the Clinical Trial?

Centre hospitalier de l'Université de Montréal (CHUM)

Lead Sponsor

Trials

389

Recruited

143,000+

Published Research Related to This Trial

In a study of 45 patients who underwent embolectomy, only 37.6% of activated partial thromboplastin time (APTT) tests were within the therapeutic range, indicating that many patients were not adequately anticoagulated with intravenous unfractionated heparin (UFH).

The authors suggest that subcutaneous low molecular weight heparin (LMWH) could be a more effective and user-friendly alternative to UFH, especially given the challenges in maintaining therapeutic levels with UFH in busy clinical settings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Audit of anticoagulation after embolectomy for acute ischaemia. Robinson, T., Hunter, I., Wathes, R., et al.[2021]

In a study of 210 patients with peripheral occlusive arterial disease, enoxaparin demonstrated superior efficacy compared to unfractionated heparin (UFH), with a significantly lower rate of thromboembolic complications during endovascular interventions (10.5% vs. 2.5%).

The use of enoxaparin also resulted in quicker achievement of therapeutic anti-factor Xa levels, with 63.7% of patients reaching these levels within 15 minutes, compared to only 39.1% in the UFH group, indicating a faster onset of action.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of enoxaparin and unfractionated heparin in endovascular interventions for the treatment of peripheral arterial occlusive disease: a randomized controlled trial. Duschek, N., Vafaie, M., Skrinjar, E., et al.[2023]

Unfractionated heparin (UFH) is the standard anticoagulant used during cardiopulmonary bypass (CPB), but it can lead to the development of heparin-dependent antibodies in 25% to 50% of patients, which may cause heparin-induced thrombocytopenia (HIT) in 1% to 3% of cases, resulting in serious complications.

For patients with a history of HIT or positive antibody titers requiring urgent cardiac surgery, alternative anticoagulants like lepirudin or bivalirudin are recommended, as well as the use of platelet antagonists to mitigate the risk of thromboembolic events.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Anticoagulation management and cardiac surgery in patients with heparin-induced thrombocytopenia. Riess, FC.[2019]

Unfractionated heparin (UFH) has been used for over 50 years to treat and prevent thrombosis, but its variable composition and unpredictable pharmacokinetics limit its effectiveness and complicate monitoring.

Newer anticoagulants, such as low-molecular-weight heparins and direct thrombin inhibitors, offer more predictable effects and eliminate the risk of heparin-induced thrombocytopenia (HIT), making them preferable alternatives to UFH.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Challenges in variation and responsiveness of unfractionated heparin. Francis, JL., Groce, JB.[2019]

In a study of 213 peripheral angioplasty procedures, 9.2% of patients experienced in-hospital major complications, including major bleeding and the need for repeat revascularization, highlighting the risks associated with using unfractionated heparin as the primary anticoagulant.

Higher doses of heparin were linked to a trend of increased complications, suggesting that careful dosing is crucial, and ongoing research is exploring the use of direct thrombin inhibitors like bivalirudin as a potentially safer alternative.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

In-hospital complications of peripheral vascular interventions using unfractionated heparin as the primary anticoagulant. Shammas, NW., Lemke, JH., Dippel, EJ., et al.[2006]

A machine learning algorithm was developed to predict activated partial thromboplastin time (aPTT) after administering unfractionated heparin (UFH), potentially improving the dosing process which currently takes over 36 hours to optimize.

The best-performing model achieved a root mean square error of 31.35 in predicting aPTT, demonstrating its effectiveness in a cohort of 3019 patient episodes across five hospitals, marking a significant advancement in the management of UFH therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predicting Therapeutic Response to Unfractionated Heparin Therapy: Machine Learning Approach. Abdel-Hafez, A., Scott, IA., Falconer, N., et al.[2022]

In a study of 200 patients with non-ST-elevation acute coronary syndrome, those receiving unfractionated heparin in dextrose 5% in water (UFH-D5W) achieved therapeutic anti-factor Xa levels within 24 hours 92% of the time, compared to only 67% for those receiving unfractionated heparin in normal saline (UFH-NS).

UFH-NS was associated with a significantly lower likelihood of achieving and maintaining therapeutic anticoagulation, requiring more adjustments to the infusion rate, indicating that UFH-D5W is the more effective preparation for anticoagulation in these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effectiveness of Unfractionated Heparin in Normal Saline versus Dextrose for Achieving and Maintaining Therapeutic Anti-Factor Xa Levels in Patients with Non-ST-Elevation Acute Coronary Syndrome. Jacques, AC., Lougheed, C., Macdonald, E., et al.[2021]

In a randomized control trial involving 30 patients with acute deep vein thrombosis, low molecular weight heparin (LMWH) showed faster improvement in pain and swelling compared to unfractionated heparin (UFH), although the differences were not statistically significant.

LMWH was associated with a normal bleeding profile and significantly shorter hospital stays, with no reported mortality, while UFH had complications including prolonged bleeding and three patient deaths.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of unfractionated heparin vs low molecular weight heparin in the treatment of acute deep vein thrombosis. Naz, R., Naz, S., Mehboob, M., et al.[2009]

Low molecular weight heparins (LMWHs) offer significant advantages over unfractionated heparin (UFH) for treating venous thromboembolism (VTE) and acute coronary syndromes, including better bioavailability, longer half-life, and predictable anticoagulant effects, allowing for less frequent dosing without the need for monitoring.

UFH is associated with risks such as bleeding and heparin-induced thrombocytopenia, while LMWHs reduce these risks and improve patient convenience, highlighting the shift towards LMWHs in clinical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perspectives on antithrombotic agents: from unfractionated heparin to new antithrombotics. Agnelli, G., Sonaglia, F.[2005]

A pharmacokinetic-pharmacodynamic (PKPD) model for unfractionated heparin (UFH) was developed using data from 64 children undergoing cardiac procedures, showing that fat-free mass (FFM) significantly influences drug clearance.

While the model accurately described UFH effects in the studied population, it overpredicted activated partial thromboplastin time (aPTT) responses when simulating lower UFH doses, suggesting a potential nonlinear relationship in heparin's pharmacokinetics and pharmacodynamics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development of a population pharmacokinetic-pharmacodynamic model of a single bolus dose of unfractionated heparin in paediatric patients. Al-Sallami, H., Newall, F., Monagle, P., et al.[2021]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7389147/

Primary prophylaxis for venous thromboembolism in people ... There was no evidence of a benefit of heparin compared with placebo for this outcome, regardless of the level of amputation. ... Subcutaneous fondaparinux versus ...

2. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/30907817/

A Randomized Controlled Trial Involving Three Groups A total of 88 patients (101 fingers) following digital amputation and subsequent repair by anastomosis of both arteries and veins were randomly allocated ...

3. researchgate.net researchgate.net/publication/8618767_Heparin_and_Low-Molecular-Weight_Heparin_Therapy_for_Venous_Thromboembolism_Will_Unfractionated_Heparin_Survive

Heparin and Low-Molecular-Weight Heparin Therapy for ... Unfractionated heparin by continuous intravenous infusion has provided an effective therapy for more than half a century, but the need to ...

4. researchgate.net researchgate.net/publication/372698244_Low-molecular-weight_heparin_is_superior_to_unfractionated_heparin_in_lowering_the_risk_of_venous_thromboembolism_after_traumatic_lower_extremity_amputation

Low-molecular-weight heparin is superior to unfractionated ... Low-molecular-weight heparin is superior to unfractionated heparin in lowering the risk of venous thromboembolism after traumatic lower extremity amputation.

5. scielo.br scielo.br/j/acb/a/6nJxGSgjQbNQhd6vFqgQ6ZS/?lang=en

Prophylaxis of deep-vein thrombosis after lower extremity ... DVT was documented in the operated limb in 9.75% in patients treated with enoxaparin and in 11.76% in patients treated with UH (p=0.92) and there was one ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT04725201

NCT04725201 | Prospective Study on the Role of ... The purpose of this study is to determine the effectiveness of therapeutic dose intravenous heparin at improving replantation/revascularization success and its ...

7. journalofethics.ama-assn.org journalofethics.ama-assn.org/article/complications-anticoagulation-heparin/2005-04

Complications of Anticoagulation with Heparin | Journal of Ethics Thrombocytopenia, bleeding events, and osteopenia are the 3 most common drug-related problems associated with heparin and LMWH therapy. These side effects often ...

8. researchgate.net researchgate.net/publication/352853975_Postoperative_Digit_and_Hand_Replantation_Protocols_A_Review_of_the_Literature

Postoperative Digit and Hand Replantation Protocols Survival rates for digital replantation now range from 57 to 90%, with outcomes potentially influenced by patient comorbidities, mechanism of injury, level of ...