Impact of Transcatheter Aortic Valve Implantation (TAVI) on the Gut Microbiota in Patients With Aortic Valve Stenosis

NCT ID: NCT07052071

Last Updated: 2025-11-18

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 40 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-09-01
• Study Completion Date: 2027-11-01

Brief 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. 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.

Conditions

Aortic Stenosis; Gut Microbiome; Gut Microbiota; TAVI; TAVI(Transcatheter Aortic Valve Implantation)

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

TAVI

TAVI

Intervention Type: PROCEDURE

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.

Interventions

TAVI

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.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• Aortic stenosis suitable for TAVI

Exclusion Criteria

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.
• Active cancer under treatment.
• Psychiatric illness impairing ability to consent.
• Substance or alcohol abuse.

• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hippocration General Hospital

OTHER

Sponsor Role: lead

Responsible Party

Konstantinos Tsioufis

Professor of Cardiology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Hippokration General Hospital of Athens

Athens, , Greece

Site Status: RECRUITING

Countries

Greece

Central Contacts

Konstantinos Tsioufis

Role: CONTACT

grammateia@acardio-ekpa.gr

+302132088099

Facility Contacts

Konstantinos Tsioufis

Role: primary

grammateia@acardio-ekpa.gr

+302132088099

Other Identifiers

GUT-TAVI

Identifier Type: -

Identifier Source: org_study_id