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Aortic StenosisPhase 3ACASA-TAVINCT05035277

AntiCoagulation Versus AcetylSalicylic Acid After Transcatheter Aortic Valve Implantation

A Phase 3 study testing Acetylsalicylic acid, Apixaban and Rivaroxaban in people with Aortic Stenosis, run by Oslo University Hospital at 3 sites in Norway.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

ACASA-TAVI is a pragmatic randomized controlled trial assessing the value of anticoagulation therapy versus the standard antiplatelet therapy after transcatheter aortic valve implantation in patients with aortic stenosis. Read more about this study

Who is it for?
Ages 65 to 80 years
Conditions the study is for
Aortic Stenosis
What is being tested?
Acetylsalicylic acid, Apixaban and Rivaroxaban
Could I receive a placebo?
No, everyone receives an active treatment
How many people
360 participants
Where
3 sitesNorway
Study dates
4 Dec 2021to 5 Jun 2026
Phase
Phase 3
Are there results?
None posted in the registry

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 65 to 80 years
  • All sexes
  • No healthy volunteers
  • Older adult

Who may be able to join

  • Successful trans-catheter aortic valve implantation in patients aged >65 and <80 years old at the time of the procedure.

Who cannot join

  • Strict indication for anticoagulation or anti-platelet drugs
  • Strict contraindication for anticoagulation or anti-platelet drugs
  • Overt cognitive failure
  • Failure to obtain written informed consent
  • Concomitant use of inducers or inhibitors of CYP3A4 or P-glycoprotein

Trial locations and contacts

3 sites in 1 country.

Norway3 sites
  • Haukeland University Hospital

    Bergen, 5021

  • Oslo Univesity Hospital - Ullevål

    Oslo, Oslo, 0424

  • Oslo University Hospital - Rikshospitalet

    Oslo, 0772

Other trials in Norway

About this study

ACASA-TAVI is a pragmatic randomized controlled trial assessing the value of anticoagulation therapy versus the standard antiplatelet therapy after transcatheter aortic valve implantation in patients with aortic stenosis. The trial will assess the efficacy of direct oral anticoagulation (DOAC) therapy compared to the standard single antiplatelet therapy to prevent degeneration of the valve and its safety in co-primary endpoints with blinded endpoint adjudication. The effect of DOAC therapy on hard clinical outcomes will be assessed during long-term follow-up.

Read the detailed description

Aortic stenosis is a highly prevalent valvular disease and an important cause of morbidity and mortality in the elderly population. Transcatheter aortic valve implantation (TAVI) is an effective intervention in patients with severe aortic stenosis and low surgical risk. The procedure is highly effective, safe, and widely implemented. Current recommendations support transcatheter treatment of younger patients, including patients from 65 years of age with low surgical risk. This practice increases the importance of long-term valve maintenance.

Observational data have suggested that early signs of valve degeneration (i.e. hypo-attenuated leaflet thickening/thrombosis/reduced leaflet motion) are associated with an increased risk of embolic events. This is an increasing problem with emerging indications in younger populations. Because both ischemic and bleeding complications after TAVI can be life-threatening, it is important to establish the optimal anti-thrombotic treatment regime. Use of oral anticoagulation after implantation for bioprosthetic valves have been associated with resolved valve degeneration and possible favourable clinical effects.

The current practice guidelines recommend that oral anticoagulation may be considered for 3 months after open surgical bioprosthetic valve implantation. Patients with an independent indication for oral anticoagulation (i.e. atrial fibrillation or venous thromboembolism) are recommended to continue this treatment lifelong, but there is no recommendation for oral anticoagulation following TAVI in patients without other indications. In patients without indication for oral anticoagulation, the use of double anti-platelet therapy for 3-6 months following TAVI is recommended. However, single anti-platelet therapy with acetylsalicylic acid (ASA) without clopidogrel has been reported to improve bleeding outcomes and a composite of bleeding and ischemic outcomes. The effect of on oral anticoagulation-based treatment strategy compared to the standard single anti-platelet treatment strategy for valve maintenance after TAVI is unknown.

Increased anti-thrombotic treatment intensity may come at the cost of increased bleeding risk. Dual anti-platelet therapy and combination therapy with anticoagulation and anti-platelet therapy have both been associated with unfavourable outcomes. Combined anti-platelet and anti-coagulation treatment has been shown to reduce valve degeneration at the cost of increased bleeding. Conversely, single anti-platelet therapy and anti-coagulation with a direct oral anti-coagulant (DOAC) have been associated with similar bleeding risk. Bleeding rates in patients treated with anti-coagulation after TAVI have been reported to be slightly higher than in patients treated with ASA after TAVI, but patients with conventional indications for anti-coagulation have higher baseline bleeding risk than those without such indications. Therefore, the risk of bleeding in patients treated with DOAC or ASA following TAVI may be similar, but no randomized trials have been performed.

ACASA-TAVI will include 360 patients > 65 years and < 80 years of age who have undergone successful TAVI and have no conventional indication for DOAC in a prospective randomized open-label blinded-endpoint (PROBE) study. The intervention arm will be 12 month therapy with an anti-Xa type DOAC (without antiplatelet therapy) and the active control arm will be standard dose ASA. After 12 months, the intervention group will be switched to ASA maintenance. All patients will undergo clinical assessment, cardiac CT and echocardiography at 12 months with blinded endpoint adjudication by an independent committee.

Outcome measures will comply with the Valve Academic Research Consortium 3 (VARC-3) consensus, and are described in detail in the protocol. The co-primary endpoints at 12 months, hypo-attenuated leaflet thickening (HALT) and safety composite, must both be met for the trial to declare success.

The effect of the DOAC therapy on long-term major adverse cardiovascular events (MACE) will be assessed after 5 years and 10 years.

Conditions
Aortic Stenosis
Being tested
Acetylsalicylic acid, Apixaban, Rivaroxaban, Edoxaban
Keywords
Transcatheter Aortic Valve Implantation, Transcatheter Aortic Valve Replacement, Antithrombotic therapy, Anticoagulation therapy, Antiplatelet therapy
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.

  • Acetylsalicylic acidDrug

    Also called B01A C06

    Acetylsalicylic acid 75 mg once daily is the current standard-of-care in TAVI patients without other indications for anticoagulation therapy.

  • ApixabanDrug

    Also called B01A F02

    Standard dose apixaban will be one of the options for the patients in the experimental arm.

  • RivaroxabanDrug

    Also called B01A F01

    Standard dose rivaroxaban will be one of the options for the patients in the experimental arm.

  • EdoxabanDrug

    Also called B01A F03

    Standard dose edoxaban will be one of the options for the patients in the experimental arm.

Study groups in NCT05035277
Study groupRoleWhat they receive
Acetylsalicylic acidActive comparatorPatients in the active control arm will receive 75 mg acetylsalicylic acid once daily indefinitely.
Receives: Drug: Acetylsalicylic acid
Direct oral anticoagulation (DOAC)ExperimentalPatients in the experimental arm will receive an anti Xa-type DOAC (apixaban, rivaroxaban or edoxaban) in approved therapeutic dose for 12 months. The choice of DOAC agent will be made by the treating clinician after discussion with the patient. After 12 months, these patients will abort DOAC therapy. Acetylsalicylic acid, 75 mg once daily will be started after DOAC discontinuation and continued indefinitely.
Receives: Drug: Apixaban; Drug: Rivaroxaban; Drug: Edoxaban

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Hypo-attenuated leaflet thickening

    First co-primary endpoint. The presence of hypo-attenuated leaflet thickening on dedicated cardiac CT after 12 months will be registered by a blinded expert reader. Intention-to-treat, superiority.

    Measured: 12 months

  2. Safety composite - Incidence of Treatment Emergent Adverse Clinical Outcome

    Second co-primary outcome. Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction or stroke) and all-cause mortality. Per-protocol, non-inferiority.

    Measured: 12 months

  3. Major adverse cardiovascular events (MACE)

    Primary outcome during long-term follow-up. The rate of the composite of Cardiac death, Aortic valve re-intervention, Stroke, Myocardial infarction, Heart failure hospitalization and Major, life-threatening, or disabling bleeding.

    Measured: 5 years

  4. Major adverse cardiovascular events (MACE)

    Primary outcome during long-term follow-up. The rate of the composite of Cardiac death, Aortic valve re-intervention, Stroke, Myocardial infarction, Heart failure hospitalization and Major, life-threatening, or disabling bleeding.

    Measured: 10 years

Secondary outcomes (10)
  1. Clinical efficacy

    First hierarchical secondary outcome. Composite of of Freedom from all-cause mortality, Freedom from all stroke, Freedom from hospitalization for procedure- or valve-related causes, Freedom from KCCQ overall summary score <45 or decline from baseline of >10 points. Intention-to-treat, superiority.

    Measured: 12 months

  2. Safety composite, superiority

    Second hierarchical secondary outcome. Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction or stroke) and all-cause mortality. Same endpoint as second co-primary outcome, but intention-to-treat, superiority.

    Measured: 12 months

  3. Thromboembolic events

    Third hierarchical secondary outcome. Composite of myocardial infarction or stroke of any cause. Intention-to-treat population.

    Measured: 12 months

  4. Bleeding events

    Fourth hierarchical secondary outcome. Bleeding events according to VARC-3 definitions. Intention-to-treat population.

    Measured: 12 months

  5. All-cause mortality

    Fifth hierarchical secondary outcome. Intention-to-treat population.

    Measured: 12 months

  6. The number of adverse events

    First secondary safety endpoint. Safety population.

    Measured: 12 months

  7. The number of serious adverse events

    Second secondary safety endpoint. Safety population.

    Measured: 12 months

  8. Life-threatening or disabling bleeding

    Third secondary safety endpoint. Safety population. VARC-3 definition.

    Measured: 12 months

  9. Major bleeding

    Fourth secondary safety endpoint. Safety population. VARC-3 definition.

    Measured: 12 months

  10. Minor bleeding

    Fifth secondary safety endpoint. Safety population. VARC-3 definition.

    Measured: 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Sep 2021
  2. Study start4 Dec 2021
  3. Primary completion5 Jun 2026
  4. Study completion5 Jun 2026

Resources

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 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Parallel group prospective randomized open blinded endpoint (PROBE) trial
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
360 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05035277
Sponsor's protocol ID
247400
Other IDs
2021-001554-61
Acronym
ACASA-TAVI
Status last verified
Jun 2026
First submitted
19 Aug 2021
Last updated
9 Jun 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: The application to share IPD is pending with the ethical committee.

Publications

  • VARC-3 WRITING COMMITTEE; Genereux P, Piazza N, Alu MC, Nazif T, Hahn RT, Pibarot P, Bax JJ, Leipsic JA, Blanke P, Blackstone EH, Finn MT, Kapadia S, Linke A, Mack MJ, Makkar R, Mehran R, Popma JJ, Reardon M, Rodes-Cabau J, Van Mieghem NM, Webb JG, Cohen DJ, Leon MB. Valve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research. Eur Heart J. 2021 May 14;42(19):1825-1857. doi: 10.1093/eurheartj/ehaa799.

    PubMed 33871579
  • Dodgson CS, Herstad J, Klove SF, Flygel M, Akhavi M, Hoie S, Beitnes JO, Eek CH, Broch K, Cunen C, Gullestad L, Aaberge L, Lunde K, Bendz B, Lie OH. Anticoagulation Monotherapy vs Antiplatelet Monotherapy After Transcatheter Aortic Valve Implant: The ACASA-TAVI Randomized Clinical Trial. JAMA. 2026 Aug 30. doi: 10.1001/jama.2026.17036. Online ahead of print.

    PubMed 42669043
  • Dodgson CS, Beitnes JO, Klove SF, Herstad J, Opdahl A, Undseth R, Eek CH, Broch K, Gullestad L, Aaberge L, Lunde K, Bendz B, Lie OH. An investigator-sponsored pragmatic randomized controlled trial of AntiCoagulation vs AcetylSalicylic Acid after Transcatheter Aortic Valve Implantation: Rationale and design of ACASA-TAVI. Am Heart J. 2023 Nov;265:225-232. doi: 10.1016/j.ahj.2023.08.010. Epub 2023 Aug 25.

    PubMed 37634655

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Acetylsalicylic acid, Apixaban and Rivaroxaban in people with Aortic Stenosis, run by Oslo University Hospital at 3 sites in Norway.

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 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: finished, as of the sponsor's last update on 9 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in Norway. 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.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Hypo-attenuated leaflet thickening (time frame: 12 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05035277, which also lists 3 linked publications.

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 9 Jun 2026.

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