Aortic StenosisPhase 4ATLASNCT06818006
Application of TAVI at Experienced Interventional Cardiac Centers Without On-site Cardiac Surgery (ATLAS Study)
A Phase 4 study testing Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight and Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight in people with Aortic Stenosis and Severe Aortic Stenosis, run by University of Alberta at 2 sites in Canada.
Trial summary
The purpose of this study is to see if having the Transcatheter Aortic Valve Replacement (TAVR) procedure done in a hospital with onsite cardiac surgery available or not, makes a difference on participant outcomes. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Aortic Stenosis, Severe Aortic Stenosis
- What is being tested?
- Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight and Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 600 participants
- Where
- 2 sitesCanada
- Study dates
- 1 Aug 2026to Dec 2030
- Phase
- Phase 4
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
- Severe symptomatic AS reviewed and accepted for Transfemoral (TF) TAVI by an established Heart Team
- Obtained informed consent
Who cannot join
- Ambiguous aortic annular sizing on CT measurement deemed to increase the risk of valve embolization
- Hostile aortic root on CT for TAVI implantation defined by, but not limited to:
- High risk LVOT with a dimension significantly smaller than the annulus and/or extensive calcification
- Features that increase the risk of coronary artery occlusion including inadequate coronary artery height and/or shallow coronary sinuses in the setting of a significant coronary artery territory at risk (accounting for prior CABG)
- High risk STJ anatomy defined by inadequate height and/or diameter and/or excessive calcification
- Vascular anatomy with increased risk of ascending aorta trauma (i.e. combinations of existing ascending aortic aneurysm, and/or unfolded aorta and/or extensive tortuosity and/or excessive iliofemoral calcification)
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- GFR <15, excluding patients on dialysis
- Life expectancy less than 3 years
- Any factor precluding 1-year follow-up
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Canada2 sites
Royal Alexandra Hospital
Edmonton, Alberta, T5H 3V9
Ben Dr. Tyrrell, MD, 780 906 7704, Ben.tyrrell@albertahealthservices.ca
Ben Tyrrell, MD
Mazankowski Heart Insitute
Edmonton, Alberta, T6G 2B7
Robert C Dr. Welsh, MD, 780 407 2685, Robert.Welsh@albertahealthservices.ca
Robert.Welsh@albertahealthservices.ca
About this study
Official title: Application of TAVI at Experienced Interventional Cardiac Centers Without On-site Cardiac Surgery
The purpose of this study is to see if having the Transcatheter Aortic Valve Replacement (TAVR) procedure done in a hospital with onsite cardiac surgery available or not, makes a difference on participant outcomes. Current standard of care is to have this procedure done in a hospital with onsite cardiac surgery available.
Hypothesis
The investigators hypothesize that the TAVR in experienced interventional cardiac centers without on-site cardiac surgery will be safe and effective. Although this is happening clinically in select regions internationally, this change in the clinical application of TAVI requires a rigorous assessment of safety with a robust randomized trial and multicenter international collaboration.
Read the detailed description
Primary Objectives:
The primary efficacy objective is to determine whether a Transcatheter Aortic Valve Implantation (TAVI) procedure performed by experienced operators in centers without on-site cardiac surgery is non-inferior to a TAVI procedure performed by experienced operators in centers with on-site cardiac surgery in terms of all-cause death, myocardial infarction, stroke and hospitalization for heart failure. The primary safety objective is to demonstrate that mortality associated with periprocedural complications actionable by emergent cardiac surgery (ECS) did not differ between study arms.
Research method/Procedures
ATLAS is an all-comer, prospective, randomized, multicenter, open label trial with blinded adjudicated evaluation of outcomes. The ATLAS study will involve centers without on-site cardiac surgery, but with experienced operators already performing TAVI. Participants will be recruited after Heart Team discussion and approval for TAVI. The eligibility of each participant will be confirmed by an established multidisciplinary Heart Team. Once approved for TAVI, dedicated review of the ATLAS study inclusion and exclusion criteria will occur. Study patients meeting inclusion and having no exclusion criteria will be randomized in a 2:1 fashion to TAVI performed in the experimental or standard of care arm stratified by two groups: 1) inoperable/high risk and 2) intermediate/low risk.
Randomization:
EXPERIMENTAL ARM: TAVI WITHOUT ON-SITE SURGERY After randomization, the participant will be scheduled to undergo TAVI by experienced operators with appropriately trained cardiac catheterization staff. CONTROL ARM: TAVI WITH ON-SITE SURGERY After randomization, the patient will be scheduled to undergo TAVI by experienced operators with appropriately trained cardiac catheterization staff at an established TAVI center with on-site cardiac surgery
Schedule of events:
- Pre-eligibility screening 2. Inclusion/Exclusion criteria review 3. Randomization 4. 1-month post randomization 5. 3-months post randomization 6. TAVI procedure hospitalization 7. 1-month visit after TAVI 8. 12-month visit after TAVI 9. Final follow-up visit - 12-month post TAVI in control arm and equivalent median time post randomization in the intervention arm
- Conditions
- Aortic Stenosis, Severe Aortic Stenosis
- Being tested
- Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight, Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight
- Keywords
- Aortic Stenosis, TAVR, TAVI, Sever aortic stenosis
- 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.
Transcatheter Aortic Valve Replacement (TAVR) with surgical oversightProcedure or surgery
Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight
Transcatheter Aortic Valve Replacement (TAVR) without surgical oversightProcedure or surgery
Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight
| Study group | Role | What they receive |
|---|---|---|
| Experimental Arm | Active comparator | EXPERIMENTAL ARM: TAVI WITHOUT ON-SITE SURGERY After randomization, the participant will be scheduled to undergo TAVI by experienced operators with appropriately trained cardiac catheterization staff. Receives: Procedure: Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight |
| Control Arms | Active comparator | CONTROL ARM: TAVI WITH ON-SITE SURGERY After randomization, the patient will be scheduled to undergo TAVI by experienced operators with appropriately trained cardiac catheterization staff at an established TAVI center with on-site cardiac surgery Receives: Procedure: Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of an Emergent CardiacSurgery (ECS) event: Ventricular
Primary Safety Outcome: Occurrence of an ECS event: Ventricular Valve Embolization, Aortic Annular Rupture, Ventricular Perforation requiring ECS or Ascending Aortic Dissection requiring ECS. Composite Endpoint of Primary Efficacy and Safety (Net clinical benefit)
Multiple measurement will result in an outcome of ECS (Emergent Cardiac Surgery).
Measured: From enrolment to the end of 90 day follow up
Death
Primary Efficacy Outcome: Composite of All Cause death from randomization.
Measured: From enrolment to the end of 90 day follow up
Myocardial Infarction
Primary Efficacy Outcome: Composite of All Cause myocardial infarction (MI) from randomization.
Measured: From enrolment to the end of 90 day follow up
Stroke
Primary Efficacy Outcome: Composite of All Cause Stroke, from randomization.
Measured: From enrolment to the end of 90 day follow up
Heart Failure Hospitalization
Primary Efficacy Outcome: Composite of All Cause Heart Failure Hospitalization from randomization.
Measured: From enrolment to the end of 90 day follow up
Secondary outcomes (17)
Individual components of primary efficacy outcome
Secondary Efficacy Outcome: Individual components of primary efficacy outcome
Measured: From enrolment to the end of 90 day follow up
Hospitalization for cardiovascular cause
Secondary Efficacy Outcome: Hospitalization for cardiovascular cause
Measured: From enrolment to the end of 90 day follow up
Permanent Pace Maker (PPM)
Secondary Efficacy Outcome: Need for Permanent Pace Maker (PPM) during study period
Measured: From enrolment to the end of 90 day follow up
Urgent percutaneous coronary revascularization
Secondary Efficacy Outcome: Need for urgent percutaneous coronary revascularization
Measured: From enrolment to the end of 90 day follow up
Acute kidney injury
Secondary Efficacy Outcome: Acute kidney injury requiring dialysis
Measured: From enrolment to the end of 90 day follow up
Procedural wait time
Secondary Efficacy Outcome: Procedural wait time from randomization to implantation date
Measured: From enrolment to the end of 90 day follow up
Length of hospital stay
Secondary Efficacy Outcome: Length of hospital stay (specific to TAVI implantation) hospitalization)
Measured: From enrolment to the end of 90 day follow up
Total days of hospitalization
Secondary Efficacy Outcome: Total days of hospitalization from randomization to end of study follow up
Measured: From enrolment to the end of 90 day follow up
Health economics analysis- Adverse Events
Monitoring and analyzing of adverse events (AEs) weight and height will be combined to report BMI in kg/m^2).
Measured: From enrolment to the end of 90 day follow up
Health economics analysis- Long-term Outcomes
Evaluation of the long-term effects of interventions on health and economic outcomes.
Measured: From enrolment to the end of 90 day follow up
Health economics analysis- Healthcare Resource Utilization
Evaluation of the use of healthcare services, such as hospital admissions, outpatient visits, and medication usage.
Measured: From enrolment to the end of 90 day follow up
Health economics analysis- Patient-Reported Outcomes (PROs
direct reports from patients about their health condition and treatment effects.
Measured: From enrolment to the end of 90 day follow up
Quality of Life
Secondary Efficacy Outcome: Quality of Life Baseline, 90 days post randomization, one year post randomization measured with Toronto Aortic Stenosis Quality of Life Questionnaire
Measured: From enrolment to the end of 90 day follow up
Emergent balloon aortic valvuloplasty
Secondary Efficacy Outcome: Need for emergent balloon aortic valvuloplasty prior to TAVI implantation required because of patent deterioration or emergent
Measured: From enrolment to the end of 90 day follow up
Major Bleeding
Secondary Efficacy Outcome: Major (type 2-4) bleeding (VARC). Multiple measurement to determine type of bleed.
Measured: From enrolment to the end of 90 day follow up
Minor Bleeding
Secondary Efficacy Outcome: Minor (type 1) bleeding (VARC). Multiple measurement to determine type of bleed.
Measured: From enrolment to the end of 90 day follow up
Secondary Efficacy Outcomes
Secondary Efficacy Outcome: Major vascular complication (VARC)
-Major or Minor vascular com
Multiple measure to determine the vascular complications outcomes
Measured: From enrolment to the end of 90 day follow up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Feb 2025
- Study start1 Aug 2026 (estimated)
- Primary completionDec 2030 (estimated)
- Study completionDec 2030 (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 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- strategy study of two processes with path way of care
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 600 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Alberta
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06818006
- Sponsor's protocol ID
- ATLAS-0000829-1
- Acronym
- ATLAS
- Status last verified
- Jun 2026
- First submitted
- 15 Jan 2025
- Last updated
- 2 Jun 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided