Aortic StenosisMICROTAVINCT07614100
Cerebral Microembolization During Transcatheter Aortic Valve Implantation: Comparing Balloon-expandable and Self-expanding Valves
A study testing Balloon-expandable transcatheter aortic valve and Self-expanding transcatheter aortic valve in people with Aortic Stenosis, run by Ivan Zeljkovic at 2 sites in Croatia.
Trial summary
This study will compare the amount of cerebral microembolization during transcatheter aortic valve implantation (TAVI) between two commonly used types of transcatheter aortic valves: balloon-expandable valves and self-expanding valves. 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?
- Balloon-expandable transcatheter aortic valve and Self-expanding transcatheter aortic valve
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 2 sitesCroatia
- Study dates
- 1 Jun 2026to 1 Feb 2027
- Phase
- Interventional
- 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
Who may be able to join
- Age 18 years or older
- Severe symptomatic aortic valve stenosis
- Clinical indication for transcatheter aortic valve implantation
- Feasibility of transcranial Doppler ultrasound monitoring
- Signed written informed consent
Who cannot join
- Recent stroke or transient ischemic attack
- Significant cerebrovascular disease preventing reliable transcranial Doppler -assessment
- Previous aortic valve implantation
- Active endocarditis
- Pregnancy or breastfeeding
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Croatia2 sites
Sisters of Charity Hospital Zagreb
Zagreb, 10000
UH Dubrava
Zagreb, 10000
About this study
Official title: Cerebral Microembolization During Transcatheter Aortic Valve Implantation: A Randomized Study Comparing Balloon-expandable and Self-expanding Valves
This study will compare the amount of cerebral microembolization during transcatheter aortic valve implantation (TAVI) between two commonly used types of transcatheter aortic valves: balloon-expandable valves and self-expanding valves.
Cerebral microembolization refers to small particles or material that may travel to the brain during the procedure. These signals can be detected using transcranial Doppler ultrasound, a non-invasive method for monitoring blood flow in the brain. Although clinically apparent stroke after TAVI is relatively uncommon, small silent brain lesions may occur, and their mechanisms are not fully understood.
Read more
Adult patients with severe symptomatic aortic valve stenosis who are scheduled for TAVI will be included. Participants will be randomly assigned to receive either a balloon-expandable or a self-expanding valve, both of which are established and routinely used treatment options. Transcranial Doppler monitoring will be performed before, during, and after the procedure to record the number of microembolic signals. The study will also record neurological events and procedural characteristics, such as procedure duration and the need for balloon dilatation.
The aim of the study is to determine whether the type of valve is associated with a different burden of cerebral microembolization during TAVI. The results may help improve understanding of procedural factors related to cerebral embolization and may support future strategies for reducing neurological risk in patients undergoing TAVI.
Read the detailed description
This is a prospective, randomized, parallel-group clinical study designed to compare cerebral microembolization during transcatheter aortic valve implantation between balloon-expandable and self-expanding transcatheter aortic valves.
The study will be conducted at University Hospital Dubrava and Sisters of Charity Hospital (Zagreb) with an expected duration of one year. Adult patients aged 18 years or older with severe symptomatic aortic valve stenosis and an indication for transcatheter aortic valve implantation will be considered for participation.
Eligible participants will be randomized using a computer-generated randomization sequence into one of two study groups according to the type of implanted valve: a balloon-expandable valve or a self-expanding valve. Both valve types represent standard, widely accepted therapeutic options in contemporary clinical practice. The study does not introduce a new or insufficiently tested technology, and participation will not change the standard course of treatment or expose patients to additional risk beyond that normally associated with the procedure.
All participants will undergo a standard TAVI procedure with periprocedural anticoagulation according to current clinical guidelines. Cerebral microembolization will be assessed using transcranial Doppler ultrasound. Monitoring will be performed immediately before the procedure, during the procedure, and after the procedure. The presence and number of microembolic signals will be recorded, including analysis across specific procedural phases such as instrumentation, valvuloplasty, valve implantation, and the post-implantation period.
The primary outcome will be the difference in the change in the number of microembolic signals between the balloon-expandable and self-expanding valve groups. Secondary outcomes will include the change in microembolic signal burden within each group, the distribution of microembolic signals across procedural phases, the occurrence of new microembolic signals after the procedure, the incidence of clinical neurological events, and the association between procedural characteristics and microembolic signal burden.
Collected data will include demographic and clinical characteristics, such as age, sex, and comorbidities, as well as procedural data including procedure duration, vascular access route, need for predilatation or postdilatation, and procedural complications. Data will be analyzed using appropriate statistical methods for between-group and within-group comparisons, depending on data distribution.
- Conditions
- Aortic Stenosis
- Being tested
- Balloon-expandable transcatheter aortic valve, Self-expanding transcatheter aortic valve
- Keywords
- Transcatheter Aortic Valve Replacement, Aortic Valve Stenosis, Microembolism
- 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.
Balloon-expandable transcatheter aortic valveDevice
A balloon-expandable transcatheter aortic valve will be implanted during a standard transcatheter aortic valve implantation procedure in participants randomized to this intervention arm. This valve type is an established and routinely used treatment option for severe symptomatic aortic valve stenosis. Cerebral microembolization will be monitored using transcranial Doppler ultrasound before, during, and after the procedure.
Self-expanding transcatheter aortic valveDevice
A self-expanding transcatheter aortic valve will be implanted during a standard transcatheter aortic valve implantation procedure in participants randomized to this intervention arm. This valve type is an established and routinely used treatment option for severe symptomatic aortic valve stenosis. Cerebral microembolization will be monitored using transcranial Doppler ultrasound before, during, and after the procedure.
| Study group | Role | What they receive |
|---|---|---|
| Balloon-Expandable Valve | Active comparator | Participants in this arm will undergo transcatheter aortic valve implantation using a balloon-expandable transcatheter aortic valve. This valve type is a standard and routinely used treatment option for patients with severe symptomatic aortic valve stenosis. Cerebral microembolization will be assessed by transcranial Doppler ultrasound before, during, and after the procedure. Receives: Device: Balloon-expandable transcatheter aortic valve |
| Self-Expanding Valve | Active comparator | articipants in this arm will undergo transcatheter aortic valve implantation using a self-expanding transcatheter aortic valve. This valve type is a standard and routinely used treatment option for patients with severe symptomatic aortic valve stenosis. Cerebral microembolization will be assessed by transcranial Doppler ultrasound before, during, and after the procedure. Receives: Device: Self-expanding transcatheter aortic valve |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Number of Cerebral Microembolic Signals During TAVI
he primary outcome is the difference between study groups in the change in the number of cerebral microembolic signals detected by transcranial Doppler ultrasound before, during, and after transcatheter aortic valve implantation. The comparison will be made between participants receiving balloon-expandable valves and those receiving self-expanding valves.
Measured: Before, during, and immediately after the TAVI procedure
Secondary outcomes (5)
Number of Cerebral Microembolic Signals Within Each Study Group
Change in the number of cerebral microembolic signals detected by transcranial Doppler ultrasound before, during, and after TAVI will be assessed separately within each valve group.
Measured: Before, during, and immediately after the TAVI procedure
Distribution of Cerebral Microembolic Signals by Procedural Phase
The number of cerebral microembolic signals will be analyzed according to procedural phase, including instrumentation, valvuloplasty, valve implantation, and the post-implantation period.
Measured: During the TAVI procedure and immediately after valve implantation
Occurrence of New Cerebral Microembolic Signals After TAVI
he occurrence and number of new cerebral microembolic signals detected after completion of the TAVI procedure will be recorded and compared between the study groups.
Measured: Immediately after the TAVI procedure
Incidence of Clinical Neurological Events
The association between procedural characteristics, including procedure duration, vascular access route, predilatation, postdilatation, and procedural complications, and the number of cerebral microembolic signals will be assessed.
Measured: Periprocedural
Correlation Between Procedure Duration and Cerebral Microembolic Signal Burden
The correlation between procedure duration, measured in minutes, and cerebral microembolic signal burden, measured as the number of cerebral microembolic signals detected by transcranial Doppler monitoring, will be assessed.
Measured: Periprocedural
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 May 2026
- Study start1 Jun 2026 (estimated)
- Primary completion30 Jan 2027 (estimated)
- Study completion1 Feb 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ivan Zeljkovic
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital Dubrava, Sisters of Mercy University Hospital
- Responsible party
- Sponsor-investigator, Ivan Zeljkovic, University Hospital Dubrava
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07614100
- Sponsor's protocol ID
- 2026/0423-10
- Acronym
- MICROTAVI
- Status last verified
- May 2026
- First submitted
- 16 May 2026
- Last updated
- 29 May 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 29 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cerebral Microembolization During Transcatheter Aortic Valve Implantation: A Randomized Study Comparing Balloon-expandable and Self-expanding Valves
- ClinicalTrials.gov ID
- NCT07614100
- Acronym / sponsor ID
- MICROTAVI / 2026/0423-10
- Conditions
- Aortic Stenosis
- Keywords
- Transcatheter Aortic Valve Replacement, Aortic Valve Stenosis, Microembolism
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Ivan ZeljkovicUniversity, hospital or other
- Collaborators
- University Hospital Dubrava, Sisters of Mercy University Hospital
- Study start
- 1 Jun 2026 (estimated)
- Primary completion
- 30 Jan 2027 (estimated)
- Study completion
- 1 Feb 2027 (estimated)
- First posted
- 29 May 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.
This study will compare the amount of cerebral microembolization during transcatheter aortic valve implantation (TAVI) between two commonly used types of transcatheter aortic valves: balloon-expandable valves and self-expanding valves.
Cerebral microembolization refers to small particles or material that may travel to the brain during the procedure. These signals can be detected using transcranial Doppler ultrasound, a non-invasive method for monitoring blood flow in the brain. Although clinically apparent stroke after TAVI is relatively uncommon, small silent brain lesions may occur, and their mechanisms are not fully understood.
Adult patients with severe symptomatic aortic valve stenosis who are scheduled for TAVI will be included. Participants will be randomly assigned to receive either a balloon-expandable or a self-expanding valve, both of which are established and routinely used treatment options. Transcranial Doppler monitoring will be performed before, during, and after the procedure to record the number of microembolic signals. The study will also record neurological events and procedural characteristics, such as procedure duration and the need for balloon dilatation.
The aim of the study is to determine whether the type of valve is associated with a different burden of cerebral microembolization during TAVI. The results may help improve understanding of procedural factors related to cerebral embolization and may support future strategies for reducing neurological risk in patients undergoing TAVI.
Detailed description
This is a prospective, randomized, parallel-group clinical study designed to compare cerebral microembolization during transcatheter aortic valve implantation between balloon-expandable and self-expanding transcatheter aortic valves.
The study will be conducted at University Hospital Dubrava and Sisters of Charity Hospital (Zagreb) with an expected duration of one year. Adult patients aged 18 years or older with severe symptomatic aortic valve stenosis and an indication for transcatheter aortic valve implantation will be considered for participation.
Eligible participants will be randomized using a computer-generated randomization sequence into one of two study groups according to the type of implanted valve: a balloon-expandable valve or a self-expanding valve. Both valve types represent standard, widely accepted therapeutic options in contemporary clinical practice. The study does not introduce a new or insufficiently tested technology, and participation will not change the standard course of treatment or expose patients to additional risk beyond that normally associated with the procedure.
All participants will undergo a standard TAVI procedure with periprocedural anticoagulation according to current clinical guidelines. Cerebral microembolization will be assessed using transcranial Doppler ultrasound. Monitoring will be performed immediately before the procedure, during the procedure, and after the procedure. The presence and number of microembolic signals will be recorded, including analysis across specific procedural phases such as instrumentation, valvuloplasty, valve implantation, and the post-implantation period.
The primary outcome will be the difference in the change in the number of microembolic signals between the balloon-expandable and self-expanding valve groups. Secondary outcomes will include the change in microembolic signal burden within each group, the distribution of microembolic signals across procedural phases, the occurrence of new microembolic signals after the procedure, the incidence of clinical neurological events, and the association between procedural characteristics and microembolic signal burden.
Collected data will include demographic and clinical characteristics, such as age, sex, and comorbidities, as well as procedural data including procedure duration, vascular access route, need for predilatation or postdilatation, and procedural complications. Data will be analyzed using appropriate statistical methods for between-group and within-group comparisons, depending on data distribution.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Balloon-Expandable Valve | Active comparator | Device: Balloon-expandable transcatheter aortic valveParticipants in this arm will undergo transcatheter aortic valve implantation using a balloon-expandable transcatheter aortic valve. This valve type is a standard and routinely used treatment option for patients with severe symptomatic aortic valve stenosis. Cerebral microembolization will be assessed by transcranial Doppler ultrasound before, during, and after the procedure. |
| Self-Expanding Valve | Active comparator | Device: Self-expanding transcatheter aortic valvearticipants in this arm will undergo transcatheter aortic valve implantation using a self-expanding transcatheter aortic valve. This valve type is a standard and routinely used treatment option for patients with severe symptomatic aortic valve stenosis. Cerebral microembolization will be assessed by transcranial Doppler ultrasound before, during, and after the procedure. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age 18 years or older
- Severe symptomatic aortic valve stenosis
- Clinical indication for transcatheter aortic valve implantation
- Feasibility of transcranial Doppler ultrasound monitoring
- Signed written informed consent
Key exclusion criteria (5 listed)
- Recent stroke or transient ischemic attack
- Significant cerebrovascular disease preventing reliable transcranial Doppler -assessment
- Previous aortic valve implantation
- Active endocarditis
- Pregnancy or breastfeeding
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 |
|---|---|---|
| Balloon-expandable transcatheter aortic valveA balloon-expandable transcatheter aortic valve will be implanted during a standard transcatheter aortic valve implantation procedure in participants randomized to this intervention arm. This valve type is an established and routinely used treatment option for severe symptomatic aortic valve stenosis. Cerebral microembolization will be monitored using transcranial Doppler ultrasound before, during, and after the procedure. | Device | Balloon-Expandable Valve |
| Self-expanding transcatheter aortic valveA self-expanding transcatheter aortic valve will be implanted during a standard transcatheter aortic valve implantation procedure in participants randomized to this intervention arm. This valve type is an established and routinely used treatment option for severe symptomatic aortic valve stenosis. Cerebral microembolization will be monitored using transcranial Doppler ultrasound before, during, and after the procedure. | Device | Self-Expanding Valve |
Primary outcome
Change in Number of Cerebral Microembolic Signals During TAVI
Time frame: Before, during, and immediately after the TAVI procedure
he primary outcome is the difference between study groups in the change in the number of cerebral microembolic signals detected by transcranial Doppler ultrasound before, during, and after transcatheter aortic valve implantation. The comparison will be made between participants receiving balloon-expandable valves and those receiving self-expanding valves.
5 secondary outcomes
Number of Cerebral Microembolic Signals Within Each Study Group
Time frame: Before, during, and immediately after the TAVI procedure
Distribution of Cerebral Microembolic Signals by Procedural Phase
Time frame: During the TAVI procedure and immediately after valve implantation
Occurrence of New Cerebral Microembolic Signals After TAVI
Time frame: Immediately after the TAVI procedure
Incidence of Clinical Neurological Events
Time frame: Periprocedural
Correlation Between Procedure Duration and Cerebral Microembolic Signal Burden
Time frame: Periprocedural
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 29 May 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.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Balloon-expandable transcatheter aortic valve and Self-expanding transcatheter aortic valve in people with Aortic Stenosis, run by Ivan Zeljkovic at 2 sites in Croatia.
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 5 inclusion and 5 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: opening soon, as of the sponsor's last update on 29 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Croatia. 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 Zeljković, PhD,MD (+385917823289, ivanzeljkov@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Number of Cerebral Microembolic Signals During TAVI (time frame: Before, during, and immediately after the TAVI procedure). 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 29 May 2026.