Aortic StenosisATOMNCT04234841
Avr Thrombosis OutcoMe Study
An observational study of Aortic Stenosis, run by East and North Hertfordshire NHS Trust at 1 site in United Kingdom.
Trial summary
This study aims to utilise novel biomarkers assessing thrombosis and thrombolysis (through a blood test), to identify patients undergoing either surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) who are at risk of thrombosis, and relate this to clinical thrombotic and… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Aortic Stenosis
- What is being tested?
- Blood test
- How many people
- 750 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Feb 2020to Jan 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All patients undergoing surgical bioprosthetic aortic valve replacement and transcatheter aortic valve implantation
Who may be able to join
- Male and female patients aged 18 years or over.
- Patients diagnosed with aortic valve disease, undergoing surgical or transcatheter AVR and free of exclusion criteria below.
- The patient is willing and able to understand the Patient Information Sheet and provide informed consent.
- The patient agrees to comply with the study protocol, including phlebotomy and imaging as required at pre-specified time points.
Who cannot join
- Inability to provide valid informed consent.
- Male and female patients aged < 18 years of age.
- The patient has, in the opinion of the investigator, significant neurological, hepatic, renal, endocrine, cardiovascular, gastrointestinal, pulmonary, haemorrhagic, metabolic or other disease likely to confound the study requirements or analyses.
- The patient has a history of substance abuse or demonstrates signs or clinical features of active substance abuse or active psychiatric disease that may result in non-compliance with visits or inability to obtain venous access.
- Alcohol consumption above recommended safe levels (i.e. more than 14 units per week owing to the potential effects of high alcohol levels on platelet reactivity).
- Any illness deemed significant by the investigator during the four (4) weeks preceding the screening period of the study such as sepsis.
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- Any major bleeding diathesis or blood dyscrasia (platelets < 70 x 109/l, Hb < 8 g/dl, INR > 1.4, APTT > x 2 UNL, leucocyte count < 3.5 x 109/l, neutrophil count < 1 x 109/l).
- Currently enrolled in an investigational device or drug trial.
- Active or disseminated malignancy at the time of recruitment.
- Additionally, for those patients taking part in the additional 4D CT angiography substudy:
- Any contraindications to CT angiography: renal failure (Cr>250 μmol/L or eGFR<30 mL/min) due to the additional risk of contrast medium nephrotoxicity; or allergy to iodine.
- Women of childbearing age who have not had a hysterectomy and/or who may be breastfeeding.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
East and North Hertfordshire NHS Trust
Stevenage, Hertforshire, SG1 4AB
Diana A Gorog, MD,PhD,FRCP, 01707247512, d.gorog@imperial.ac.uk
About this study
Official title: Can Thrombosis and Fibrinolysis Markers in Patients Undergoing Aortic Valve Replacement Predict Outcome
This study aims to utilise novel biomarkers assessing thrombosis and thrombolysis (through a blood test), to identify patients undergoing either surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) who are at risk of thrombosis, and relate this to clinical thrombotic and thromboembolic adverse events and subclinical valve thrombosis, and identify the timeframe of greatest risk for valve thrombosis.
Read the detailed description
Recent studies have highlighted the risk of peri-operative thrombosis in patients undergoing aortic valve replacement (AVR) and the subsequent risk of subclinical valve thrombosis in bioprosthetic AVR. The risk is significantly greater with transcatheter aortic valve implantation (TAVI) than surgical aortic valve replacement (SAVR), and can lead to stroke and other neurological events including death, and early valve failure secondary to restricted leaflet mobility.
Whilst oral anticoagulation (OAC) can reduce thrombosis, OAC has been shown to significantly and unacceptably increase the risk of bleeding when applied to all-comers undergoing TAVI. It would therefore be desirable to identify which patients are at increased thrombosis risk so these can be targeted with antithrombotic medications, whilst avoiding unnecessary bleeding risk in low risk patients.
In this study will aim to identify those patients at greatest risk of thrombosis using novel biomarkers (assessing thrombosis and thrombolysis), and note whether these tests are able to predict adverse events.
The tests for thrombosis and thrombolysis will involve a blood draw, which will be taken at various time points in the study to signal the time point of greatest thrombogenicity, which may be dependent on anti-platelet and anticoagulant therapy that the patient is prescribed.
Adverse events include MACCE (myocardial infarction, stroke, TIA (transient ischaemic attack) and death), systemic embolism, clinical and subclinical valve thrombosis, valve restriction and bleeding.
4D CT, echocardiography and clinical reviews will be performed at regular time points in the study to identify adverse events. The follow-up for each patent will be 5 years.
- Conditions
- Aortic Stenosis
- Being tested
- Blood test
- Keywords
- TAVI, SAVR
- Medical subject headings
- Aortic Valve Stenosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood testDiagnostic test
Blood test
| Study group | Role | What they receive |
|---|---|---|
| Surgical Aortic Valve Replacement (SAVR) | This cohort includes patients who will be undergoing surgical aortic valve replacement Receives: Diagnostic Test: Blood test | |
| Transcatheter Aortic Valve Implantation (TAVI) | This cohort includes patients who will be undergoing Transcatheter Aortic Valve Implantation Receives: Diagnostic Test: Blood test |
What is being measured
The primary outcome is the main question the study is designed to answer.
MACCE
Myocardial infarction, Stroke, Transient Ischaemic Attack (TIA), death
Measured: 5 years (total duration of study)
Bleeding
BARC
Measured: 5 years (total duration of study)
Systemic embolism
Measured: 5 years (total duration of study)
Secondary outcomes (2)
Subclinical valve thrombosis
Measured: 5 years (total duration of study)
New/worsening AF
Measured: 5 years (total duration of study)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Jan 2020
- Study start1 Feb 2020
- Primary completionJan 2028 (estimated)
- Study completionJan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Aortic StenosisStudies of the same condition, open and under way.
- 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
- 750 participants (estimated)
Sponsor and investigators
- Lead sponsor
- East and North Hertfordshire NHS Trust
- Sponsor type
- Other government
- Collaborators
- Royal Brompton & Harefield NHS Foundation Trust
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04234841
- Sponsor's protocol ID
- RD2019-11
- Acronym
- ATOM
- Status last verified
- Jul 2026
- First submitted
- 16 Jan 2020
- Last updated
- 15 Jul 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 15 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Can Thrombosis and Fibrinolysis Markers in Patients Undergoing Aortic Valve Replacement Predict Outcome
- ClinicalTrials.gov ID
- NCT04234841
- Acronym / sponsor ID
- ATOM / RD2019-11
- Conditions
- Aortic Stenosis
- Keywords
- TAVI, SAVR
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 750 participants (estimated)
- Lead sponsor
- East and North Hertfordshire NHS TrustOther government
- Collaborators
- Royal Brompton & Harefield NHS Foundation Trust
- Study start
- 1 Feb 2020 (actual)
- Primary completion
- Jan 2028 (estimated)
- Study completion
- Jan 2028 (estimated)
- First posted
- 21 Jan 2020 (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.
This study aims to utilise novel biomarkers assessing thrombosis and thrombolysis (through a blood test), to identify patients undergoing either surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) who are at risk of thrombosis, and relate this to clinical thrombotic and thromboembolic adverse events and subclinical valve thrombosis, and identify the timeframe of greatest risk for valve thrombosis.
Detailed description
Recent studies have highlighted the risk of peri-operative thrombosis in patients undergoing aortic valve replacement (AVR) and the subsequent risk of subclinical valve thrombosis in bioprosthetic AVR. The risk is significantly greater with transcatheter aortic valve implantation (TAVI) than surgical aortic valve replacement (SAVR), and can lead to stroke and other neurological events including death, and early valve failure secondary to restricted leaflet mobility.
Whilst oral anticoagulation (OAC) can reduce thrombosis, OAC has been shown to significantly and unacceptably increase the risk of bleeding when applied to all-comers undergoing TAVI. It would therefore be desirable to identify which patients are at increased thrombosis risk so these can be targeted with antithrombotic medications, whilst avoiding unnecessary bleeding risk in low risk patients.
In this study will aim to identify those patients at greatest risk of thrombosis using novel biomarkers (assessing thrombosis and thrombolysis), and note whether these tests are able to predict adverse events.
The tests for thrombosis and thrombolysis will involve a blood draw, which will be taken at various time points in the study to signal the time point of greatest thrombogenicity, which may be dependent on anti-platelet and anticoagulant therapy that the patient is prescribed.
Adverse events include MACCE (myocardial infarction, stroke, TIA (transient ischaemic attack) and death), systemic embolism, clinical and subclinical valve thrombosis, valve restriction and bleeding.
4D CT, echocardiography and clinical reviews will be performed at regular time points in the study to identify adverse events. The follow-up for each patent will be 5 years.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Surgical Aortic Valve Replacement (SAVR) | – | Diagnostic Test: Blood testThis cohort includes patients who will be undergoing surgical aortic valve replacement |
| Transcatheter Aortic Valve Implantation (TAVI) | – | Diagnostic Test: Blood testThis cohort includes patients who will be undergoing Transcatheter Aortic Valve Implantation |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All patients undergoing surgical bioprosthetic aortic valve replacement and transcatheter aortic valve implantation
Key inclusion criteria (4 listed)
- Male and female patients aged 18 years or over.
- Patients diagnosed with aortic valve disease, undergoing surgical or transcatheter AVR and free of exclusion criteria below.
- The patient is willing and able to understand the Patient Information Sheet and provide informed consent.
- The patient agrees to comply with the study protocol, including phlebotomy and imaging as required at pre-specified time points.
Key exclusion criteria (12 listed)
- Inability to provide valid informed consent.
- Male and female patients aged < 18 years of age.
- The patient has, in the opinion of the investigator, significant neurological, hepatic, renal, endocrine, cardiovascular, gastrointestinal, pulmonary, haemorrhagic, metabolic or other disease likely to confound the study requirements or analyses.
- The patient has a history of substance abuse or demonstrates signs or clinical features of active substance abuse or active psychiatric disease that may result in non-compliance with visits or inability to obtain venous access.
- Alcohol consumption above recommended safe levels (i.e. more than 14 units per week owing to the potential effects of high alcohol levels on platelet reactivity).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Blood testBlood test | Diagnostic test | Surgical Aortic Valve Replacement (SAVR), Transcatheter Aortic Valve Implantation (TAVI) |
Primary outcome
MACCE
Time frame: 5 years (total duration of study)
Myocardial infarction, Stroke, Transient Ischaemic Attack (TIA), death
Bleeding
Time frame: 5 years (total duration of study)
BARC
Systemic embolism
Time frame: 5 years (total duration of study)
2 secondary outcomes
Subclinical valve thrombosis
Time frame: 5 years (total duration of study)
New/worsening AF
Time frame: 5 years (total duration of study)
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 15 Jul 2026.
- Individual participant dataSharing planned: No
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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.
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 Aortic Stenosis, run by East and North Hertfordshire NHS Trust at 1 site in United Kingdom.
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 4 inclusion and 12 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 15 Jul 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 Kingdom. 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 Diana A Gorog, MD,PhD,FRCP (01707247512, d.gorog@imperial.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
MACCE (time frame: 5 years (total duration of study)). The study lists 3 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 15 Jul 2026.