Aortic StenosisGUT-TAVINCT07052071
Impact of Transcatheter Aortic Valve Implantation (TAVI) on the Gut Microbiota in Patients With Aortic Valve Stenosis
An observational study of Aortic Stenosis and Gut Microbiome, run by Hippocration General Hospital at 1 site in Greece.
Trial summary
This study investigates the impact of transcatheter aortic valve implantation (TAVI) on the composition and function of the gut microbiota in patients with severe aortic valve stenosis. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Aortic Stenosis, Gut Microbiome, Gut Microbiota
- What is being tested?
- TAVI
- Type of treatment
- Surgery or procedure
- How many people
- 40 participants
- Where
- 1 siteGreece
- Study dates
- 1 Sep 2025to 1 Nov 2027
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study will include 40 patients undergoing clinically indicated TAVI at the Hemodynamic Laboratory of the "Hippokration" General Hospital of Athens. This sample size is considered sufficient based on the limited available literature. Interim analysis will be conducted after the first 10 patients have completed the study to reassess and, if necessary, adjust the final sample size. Written informed consent is a prerequisite for inclusion.
Who may be able to join
- Aortic stenosis suitable for TAVI
Who cannot join
- Patients will be excluded if they present any condition or intervention that may independently affect gut microbiota composition. These include:
- Use of antibiotics, systemic corticosteroids, antivirals, probiotics, bile acid sequestrants, or new medications within one month prior to enrollment.
- History of inflammatory bowel disease.
- End-stage renal disease requiring dialysis.
- End-stage chronic liver disease.
- Acute infection. Patients with aortic stenosis due to rheumatic fever or infectious endocarditis will be excluded.
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- Active cancer under treatment.
- Psychiatric illness impairing ability to consent.
- Substance or alcohol abuse.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Greece1 site, 1 recruiting
- Recruiting
Hippokration General Hospital of Athens
Athens
Konstantinos Tsioufis, +302132088099, grammateia@acardio-ekpa.gr
About this study
This study investigates the impact of transcatheter aortic valve implantation (TAVI) on the composition and function of the gut microbiota in patients with severe aortic valve stenosis. The improvement in haemodynamics following TAVI may positively influence gut microbial balance by increasing splanchnic perfusion and reducing intestinal congestion. A total of 40 patients undergoing TAVI at the "Hippokration" General Hospital of Athens will be enrolled, with the aim of analysing stool and blood samples before and after the procedure. The primary endpoint is the change in gut microbiota composition two months post-TAVI, assessed via 16S rRNA sequencing. Secondary endpoints include changes in serum TMAO levels and their association with the severity of aortic stenosis and post-procedural valve haemodynamics. Data will be collected at two timepoints (1 month up to 1 day pre-TAVI and 3 to 4 months post-TAVI), along with dietary questionnaires to account for potential confounding factors. This observational study aims to highlight the potential relationship between cardiac function and the gut microbiome, offering new perspectives for targeted therapeutic strategies in cardiovascular disease.
Read the detailed description
Hypothesis The interaction between transcatheter aortic valve implantation (TAVI) and the gut microbiota represents an emerging field of investigation with potential clinical implications. Beyond restoring haemodynamic function, TAVI may influence the composition and function of the gut microbiome through several mechanisms. Improved cardiac output following TAVI enhances splanchnic perfusion, potentially reducing mucosal oedema and congestion, which may restore intestinal permeability and lead to favourable changes in microbiome composition.
Study Objective To evaluate changes in the gut microbiota following TAVI in patients with severe aortic valve stenosis.
Study Timeline and Data Collection Phase 1: Screening and Baseline Data Collection (1 month to 24 hours before TAVI, T1) Participants will be assessed for eligibility based on inclusion/exclusion criteria. Informed consent will be obtained, and participants will agree to telephone follow-up.
Collected data will include:
- Demographics and anthropometrics: sex, age, weight, height, BMI
- Social history: smoking, alcohol, substance use
- Medical history: comorbidities including hypertension, diabetes, dyslipidaemia, vascular disease, heart failure, stroke, TIA, embolism, PE
- Echocardiography parameters
- Venous Blood Sample (T1):
Collected up to 24 hours before TAVI for the following markers: TMAO, Complete blood count, Liver enzymes (SGOT, SGPT, ALP, γ-GT), Renal function (urea, creatinine), Electrolytes (K⁺, Na⁺, Ca²⁺, Mg²⁺), NT-proBNP, hsCRP, eGFR using the Cockcroft-Gault equation.
- Stool Sample \& Dietary Assessment (T1): Participants will collect a stool sample using a standardised kit for 16S rRNA sequencing. A food frequency questionnaire will be completed to account for dietary influences on microbiota. This questionnaire will be repeated at each sample collection.
Sample Collection Procedure:
Participants will follow hygiene protocols and use provided containers for stool collection. Samples will be labeled with study ID, sample sequence (A or B), date of collection, and procedure type, and will be returned to the hospital promptly. No identifiable information will be recorded on the specimen.
Phase 2: Follow-Up (3-4 months after TAVI, T2) All assessments will be repeated 3 months post-procedure. If antibiotics were taken within this period, the follow-up assessment will be delayed by 1 month (i.e., 4 months post-TAVI).
Timepoint Comparisons:
T1 vs T2: Assess the impact of TAVI on gut microbiota.
- Conditions
- Aortic Stenosis, Gut Microbiome, Gut Microbiota, TAVI, TAVI(Transcatheter Aortic Valve Implantation)
- Being tested
- TAVI
- Keywords
- TAVI
- 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.
TAVIProcedure or surgery
Transcatheter Aortic Valve Implantation (TAVI) is a minimally invasive method for replacing the aortic valve in patients with severe aortic stenosis. The procedure involves the placement of a bioprosthetic valve within the patient's degenerated aortic valve via a catheter.
| Study group | Role | What they receive |
|---|---|---|
| TAVI | Not described Receives: Procedure: TAVI |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in gut microbiota composition (via 16S rRNA sequencing)
Measured: 3 months post TAVI
Secondary outcomes (3)
Change in serum trimethylamine N-oxide (TMAO) levels
Measured: 3 months post TAVI
Correlation of microbiota changes with severity of aortic stenosis at baseline
Measured: 3 months post TAVI
Correlation of microbiota changes with haemodynamic parameters
Measured: 3 months post TAVI
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jul 2025
- Study start1 Sep 2025
- Primary completion1 Sep 2027 (estimated)
- Study completion1 Nov 2027 (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
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hippocration General Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Konstantinos Tsioufis, Hippocration General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07052071
- Sponsor's protocol ID
- GUT-TAVI
- Acronym
- GUT-TAVI
- Status last verified
- Nov 2025
- First submitted
- 26 Jun 2025
- Last updated
- 18 Nov 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 18 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Transcatheter Aortic Valve Implantation (TAVI) on the Gut Microbiota in Patients With Aortic Valve Stenosis
- ClinicalTrials.gov ID
- NCT07052071
- Acronym / sponsor ID
- GUT-TAVI / GUT-TAVI
- Conditions
- Aortic Stenosis, Gut Microbiome, Gut Microbiota, TAVI, TAVI(Transcatheter Aortic Valve Implantation)
- Keywords
- TAVI
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Hippocration General HospitalUniversity, hospital or other
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- 1 Sep 2027 (estimated)
- Study completion
- 1 Nov 2027 (estimated)
- First posted
- 4 Jul 2025 (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 investigates the impact of transcatheter aortic valve implantation (TAVI) on the composition and function of the gut microbiota in patients with severe aortic valve stenosis. The improvement in haemodynamics following TAVI may positively influence gut microbial balance by increasing splanchnic perfusion and reducing intestinal congestion. A total of 40 patients undergoing TAVI at the "Hippokration" General Hospital of Athens will be enrolled, with the aim of analysing stool and blood samples before and after the procedure. The primary endpoint is the change in gut microbiota composition two months post-TAVI, assessed via 16S rRNA sequencing. Secondary endpoints include changes in serum TMAO levels and their association with the severity of aortic stenosis and post-procedural valve haemodynamics. Data will be collected at two timepoints (1 month up to 1 day pre-TAVI and 3 to 4 months post-TAVI), along with dietary questionnaires to account for potential confounding factors. This observational study aims to highlight the potential relationship between cardiac function and the gut microbiome, offering new perspectives for targeted therapeutic strategies in cardiovascular disease.
Detailed description
Hypothesis The interaction between transcatheter aortic valve implantation (TAVI) and the gut microbiota represents an emerging field of investigation with potential clinical implications. Beyond restoring haemodynamic function, TAVI may influence the composition and function of the gut microbiome through several mechanisms. Improved cardiac output following TAVI enhances splanchnic perfusion, potentially reducing mucosal oedema and congestion, which may restore intestinal permeability and lead to favourable changes in microbiome composition.
Study Objective To evaluate changes in the gut microbiota following TAVI in patients with severe aortic valve stenosis.
Study Timeline and Data Collection Phase 1: Screening and Baseline Data Collection (1 month to 24 hours before TAVI, T1) Participants will be assessed for eligibility based on inclusion/exclusion criteria. Informed consent will be obtained, and participants will agree to telephone follow-up.
Collected data will include:
- Demographics and anthropometrics: sex, age, weight, height, BMI
- Social history: smoking, alcohol, substance use
- Medical history: comorbidities including hypertension, diabetes, dyslipidaemia, vascular disease, heart failure, stroke, TIA, embolism, PE
- Echocardiography parameters
- Venous Blood Sample (T1):
Collected up to 24 hours before TAVI for the following markers: TMAO, Complete blood count, Liver enzymes (SGOT, SGPT, ALP, γ-GT), Renal function (urea, creatinine), Electrolytes (K⁺, Na⁺, Ca²⁺, Mg²⁺), NT-proBNP, hsCRP, eGFR using the Cockcroft-Gault equation.
- Stool Sample \& Dietary Assessment (T1): Participants will collect a stool sample using a standardised kit for 16S rRNA sequencing. A food frequency questionnaire will be completed to account for dietary influences on microbiota. This questionnaire will be repeated at each sample collection.
Sample Collection Procedure:
Participants will follow hygiene protocols and use provided containers for stool collection. Samples will be labeled with study ID, sample sequence (A or B), date of collection, and procedure type, and will be returned to the hospital promptly. No identifiable information will be recorded on the specimen.
Phase 2: Follow-Up (3-4 months after TAVI, T2) All assessments will be repeated 3 months post-procedure. If antibiotics were taken within this period, the follow-up assessment will be delayed by 1 month (i.e., 4 months post-TAVI).
Timepoint Comparisons:
T1 vs T2: Assess the impact of TAVI on gut microbiota.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| TAVI | – | Procedure: TAVI |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study will include 40 patients undergoing clinically indicated TAVI at the Hemodynamic Laboratory of the "Hippokration" General Hospital of Athens. This sample size is considered sufficient based on the limited available literature. Interim analysis will be conducted after the first 10 patients have completed the study to reassess and, if necessary, adjust the final sample size. Written informed consent is a prerequisite for inclusion.
Key inclusion criteria (1 listed)
- Aortic stenosis suitable for TAVI
Key exclusion criteria (9 listed)
- Patients will be excluded if they present any condition or intervention that may independently affect gut microbiota composition. These include:
- Use of antibiotics, systemic corticosteroids, antivirals, probiotics, bile acid sequestrants, or new medications within one month prior to enrollment.
- History of inflammatory bowel disease.
- End-stage renal disease requiring dialysis.
- End-stage chronic liver disease.
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 |
|---|---|---|
| TAVITranscatheter Aortic Valve Implantation (TAVI) is a minimally invasive method for replacing the aortic valve in patients with severe aortic stenosis. The procedure involves the placement of a bioprosthetic valve within the patient's degenerated aortic valve via a catheter. | Procedure or surgery | TAVI |
Primary outcome
Change in gut microbiota composition (via 16S rRNA sequencing)
Time frame: 3 months post TAVI
3 secondary outcomes
Change in serum trimethylamine N-oxide (TMAO) levels
Time frame: 3 months post TAVI
Correlation of microbiota changes with severity of aortic stenosis at baseline
Time frame: 3 months post TAVI
Correlation of microbiota changes with haemodynamic parameters
Time frame: 3 months post TAVI
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 18 Nov 2025.
- Individual participant dataSharing planned: Undecided
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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 and Gut Microbiome, run by Hippocration General Hospital at 1 site in Greece.
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 1 inclusion and 9 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 18 Nov 2025. 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 Greece. 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 Konstantinos Tsioufis (+302132088099, grammateia@acardio-ekpa.gr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in gut microbiota composition (via 16S rRNA sequencing) (time frame: 3 months post TAVI). 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 18 Nov 2025.