Application of TAVI at Experienced Interventional Cardiac Centers Without On-site Cardiac Surgery (ATLAS Study) (ATLAS)

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Aortic Stenosis; Severe Aortic Stenosis
• Intervention / Treatment: Procedure: Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight; Procedure: Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight

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:

1. 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

• Study Type: Interventional
• Enrollment (Estimated): 600
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Dr. Robert Welsh C Welsh, MD; Phone Number: 780 407 2685; Email: Robert.Welsh@albertahealthservices.ca

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T5H 3V9
      • Royal Alexandra Hospital
      • Contact: Ben Dr. Tyrrell, MD; Phone Number: 780 906 7704; Email: Ben.tyrrell@albertahealthservices.ca
      • Principal Investigator: Ben Tyrrell, MD
    • Edmonton, Alberta, Canada, T6G 2B7
      • Mazankowski Heart Insitute
      • Contact: Robert C Dr. Welsh, MD; Phone Number: 780 407 2685; Email: Robert.Welsh@albertahealthservices.ca
      • Contact: Email: Robert.Welsh@albertahealthservices.ca
      • Principal Investigator: Robert C Welsh, MD
      • Sub-Investigator: Ben Tyrrell, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Severe symptomatic AS reviewed and accepted for Transfemoral (TF) TAVI by an established Heart Team
• Obtained informed consent

Exclusion Criteria:

• 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)
• GFR <15, excluding patients on dialysis
• Life expectancy less than 3 years
• Any factor precluding 1-year follow-up

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Experimental Arm; 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.	Procedure: Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight; Transcatheter Aortic Valve Replacement (TAVR) without surgical oversight
Active Comparator: Control Arms; 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	Procedure: Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight; Transcatheter Aortic Valve Replacement (TAVR) with surgical oversight

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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).	From enrolment to the end of 90 day follow up
Death	Primary Efficacy Outcome: Composite of All Cause death from randomization.	From enrolment to the end of 90 day follow up
Myocardial Infarction	Primary Efficacy Outcome: Composite of All Cause myocardial infarction (MI) from randomization.	From enrolment to the end of 90 day follow up
Stroke	Primary Efficacy Outcome: Composite of All Cause Stroke, from randomization.	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.	From enrolment to the end of 90 day follow up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Individual components of primary efficacy outcome	Secondary Efficacy Outcome: Individual components of primary efficacy outcome	From enrolment to the end of 90 day follow up
Hospitalization for cardiovascular cause	Secondary Efficacy Outcome: Hospitalization for cardiovascular cause	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	From enrolment to the end of 90 day follow up
Urgent percutaneous coronary revascularization	Secondary Efficacy Outcome: Need for urgent percutaneous coronary revascularization	From enrolment to the end of 90 day follow up
Acute kidney injury	Secondary Efficacy Outcome: Acute kidney injury requiring dialysis	From enrolment to the end of 90 day follow up
Procedural wait time	Secondary Efficacy Outcome: Procedural wait time from randomization to implantation date	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)	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	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).	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.	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.	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.	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	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	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.	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.	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	From enrolment to the end of 90 day follow up

Collaborators and Investigators

• Sponsor: University of Alberta

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): December 1, 2030
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: January 15, 2025
• First Submitted That Met QC Criteria: February 7, 2025
• First Posted (Actual): February 10, 2025

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Aortic Stenosis; TAVI; TAVR; Sever aortic stenosis
• Additional Relevant MeSH Terms: Aortic Valve Disease; Cardiovascular Diseases; Heart Diseases; Heart Valve Diseases; Ventricular Outflow Obstruction; Aortic Valve Stenosis; Surgical Procedures, Operative; Cardiovascular Surgical Procedures; Cardiac Surgical Procedures; Thoracic Surgical Procedures; Prosthesis Implantation; Heart Valve Prosthesis Implantation; Transcatheter Aortic Valve Replacement
• Other Study ID Numbers: ATLAS-0000829-1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No