Circadian Variation in Anti-Factor Xa (Anti-FXa) ActivityNCT07856641
Circadian Variation of Anti-Factor Xa in Hospitalized Trauma Patients
An observational study of Circadian Variation in Anti-Factor Xa (Anti-FXa) Activity, run by The University of Texas Health Science Center, Houston at 1 site in United States.
Trial summary
The purpose of this study is to determine whether a circadian rhythm exists in anti-FXa levels and AT3 activity in hospitalized trauma patients receiving low-molecular-weight heparin (LMWH) chemoprophylaxis Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Circadian Variation in Anti-Factor Xa (Anti-FXa) Activity
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 26 Aug 2026to 26 Mar 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study will be conducted at HCA Houston Northwest Medical Center and will include adult trauma patients admitted to the Trauma ICU and Trauma Surgical Floor
Who may be able to join
- Inpatient admission for acute traumatic injury ≥72 hours
- Prescribed LMWH subcutaneous for VTE chemoprophylaxis
Who cannot join
- Pregnancy
- Brain hemorrhage or non-survivable injury
- Chronic Kidney disease ≥ 3b estimated Glomerular Filtration Rate (eGFR) less than 30 interferes with coagulation
- Chronic liver failure
- •-Acute stimulant use of cocaine and methamphetamine
- Active VTE or ongoing anticoagulation at admission
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- History of coagulopathy or inherited bleeding disorders
- Chronic alcohol as defined as a documented diagnosis of alcohol use disorder or alcohol consumption exceeding established risk thresholds (men >14 drinks/week; women >7 drinks/week) within the prior 3-6 months
- Unmanaged psychiatric conditions as defined as diagnosed psychiatric disorder with evidence of inadequate or no active treatment or documented poor symptom control
- Neurologic injury involving hypothalamic or circadian regulatory centers
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
HCA Houston Northwest Medical Center
Houston, Texas, 77090
Evaline W Kihara, MSN, APRN, AGACNP-BC, CCRN, (713) 500-6362, Evaline.W.Kihara@uth.tmc.edu
Nikhil Padhye, (713) 500-2035, Nikhil.S.Padhye@uth.tmc.edu
About this study
The purpose of this study is to determine whether a circadian rhythm exists in anti-FXa levels and AT3 activity in hospitalized trauma patients receiving low-molecular-weight heparin (LMWH) chemoprophylaxis
- Keywords
- Blood thinner, circadian rhythm, Venous thromboembolism (VTE)
- Medical subject headings
- Motor Activity, Venous Thromboembolism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Hospitalized Trauma Patients Receiving LMWH Chemoprophylaxis | Hospitalized trauma patients receiving low-molecular-weight heparin (LMWH) chemoprophylaxis as part of routine clinical care. Participants will have anti-FXa levels and antithrombin III (AT3) activity measured at predefined time points to evaluate potential circadian variation in these measures. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in anti-factor Xa (anti-FXa) levels
Measured: 4 hours after the 3rd LMWH dose (T0), then every 6 hours (T6, T12, T18)
Change in Antithrombin III (AT3) activity
Measured: 4 hours after the 3rd LMWH dose (T0), then every 6 hours (T6, T12, T18)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Oct 2026
- Study start26 Aug 2026
- Primary completion26 Aug 2027 (estimated)
- Study completion26 Mar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Circadian Variation in Anti-Factor Xa (Anti-FXa) ActivityStudies of the same condition, open and under way.
- More trials run by The University of Texas Health Science Center, HoustonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Collaborators
- Sigma Theta Tau International Grant; Jerold B. Katz Endowment Fund
- Responsible party
- Principal investigator, Evaline Kihara, The University of Texas Health Science Center, Houston
- Investigators
- Evaline W Kihara, MSN, APRN, AGACNP-BC, CCRN, Principal investigator, The University of Texas Health Science Center, HoustonShiree Berry, MD, Study director, HCA Houston NW Medical center- Trauma Medical Director
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07856641
- Sponsor's protocol ID
- HSC-SN-25-0184
- Status last verified
- Sep 2026
- First submitted
- 28 Sep 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Circadian Variation of Anti-Factor Xa in Hospitalized Trauma Patients
- ClinicalTrials.gov ID
- NCT07856641
- Acronym / sponsor ID
- HSC-SN-25-0184
- Keywords
- Blood thinner, circadian rhythm, Venous thromboembolism (VTE)
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- The University of Texas Health Science Center, HoustonUniversity, hospital or other
- Collaborators
- Sigma Theta Tau International Grant; Jerold B. Katz Endowment Fund
- Study start
- 26 Aug 2026 (actual)
- Primary completion
- 26 Aug 2027 (estimated)
- Study completion
- 26 Mar 2028 (estimated)
- First posted
- 2 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine whether a circadian rhythm exists in anti-FXa levels and AT3 activity in hospitalized trauma patients receiving low-molecular-weight heparin (LMWH) chemoprophylaxis
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Hospitalized Trauma Patients Receiving LMWH Chemoprophylaxis | – | –Hospitalized trauma patients receiving low-molecular-weight heparin (LMWH) chemoprophylaxis as part of routine clinical care. Participants will have anti-FXa levels and antithrombin III (AT3) activity measured at predefined time points to evaluate potential circadian variation in these measures. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study will be conducted at HCA Houston Northwest Medical Center and will include adult trauma patients admitted to the Trauma ICU and Trauma Surgical Floor
Key inclusion criteria (2 listed)
- Inpatient admission for acute traumatic injury ≥72 hours
- Prescribed LMWH subcutaneous for VTE chemoprophylaxis
Key exclusion criteria (10 listed)
- Pregnancy
- Brain hemorrhage or non-survivable injury
- Chronic Kidney disease ≥ 3b estimated Glomerular Filtration Rate (eGFR) less than 30 interferes with coagulation
- Chronic liver failure
- •-Acute stimulant use of cocaine and methamphetamine
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in anti-factor Xa (anti-FXa) levels
Time frame: 4 hours after the 3rd LMWH dose (T0), then every 6 hours (T6, T12, T18)
Change in Antithrombin III (AT3) activity
Time frame: 4 hours after the 3rd LMWH dose (T0), then every 6 hours (T6, T12, T18)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Evaline W Kihara, MSN, APRN, AGACNP-BC, CCRN principal investigator
The University of Texas Health Science Center, Houston
Shiree Berry, MD study director
HCA Houston NW Medical center- Trauma Medical Director
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Circadian Variation in Anti-Factor Xa (Anti-FXa) Activity, run by The University of Texas Health Science Center, Houston at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Evaline W Kihara, MSN, APRN, AGACNP-BC, CCRN ((713) 500-6362, Evaline.W.Kihara@uth.tmc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in anti-factor Xa (anti-FXa) levels (time frame: 4 hours after the 3rd LMWH dose (T0), then every 6 hours (T6, T12, T18)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026.