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Atrial FibrillationNCT05147792

The CONFORM Pivotal Trial

A study testing CLAAS and WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder in people with Atrial Fibrillation and Stroke, run by Conformal Medical, Inc at 94 sites in 6 countries.

Suspended

Paused. Enrolment is on hold for now and may resume.

Official record
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Trial summary

The CLAAS® device will be evaluated for safety and efficacy by establishing its performance is non-inferior to the commercially available WATCHMAN® and Amulet™ left atrial appendage closure devices in patients with non-valvular atrial fibrillation. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Atrial Fibrillation, Stroke
What is being tested?
CLAAS and WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
1,600 participants
Where
94 sitesin 6 countries
Study dates
26 May 2022to Dec 2031
Phase
Interventional
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 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Male or non-pregnant female aged ≥18 years
  • Documented non-valvular AF (paroxysmal, persistent, or permanent)
  • High risk of stroke or systemic embolism, defined as CHA2DS2-VASc score of ≥ 3
  • Has an appropriate rationale to seek a non-pharmacologic alternative to long-term oral anticoagulation
  • Deemed by the site investigator to be suitable for short term oral anticoagulation therapy but deemed less favorable for long-term oral anticoagulation therapy.
  • Deemed appropriate for LAA closure by the site investigator and a clinician not a part of the procedural team using a shared decision-making process in accordance with standard of care
  • Able to comply with the protocol-specified medication regimen and follow-up evaluations
  • The subject (or legally authorized representative, where allowed) has been informed of the nature of the study, agrees to its provisions, and has provided written informed consent approved by the appropriate institutional review board (IRB)/Regional Ethics Board (REB)/Ethics Committee (EC).

Who cannot join

  • Pregnant or nursing patients and those who plan pregnancy in the period up to one year following the index procedure. Female patients of childbearing potential must have a negative pregnancy test (per site standard test) within 7 days prior to index procedure.
  • Anatomic conditions that would prevent performance of an LAA occlusion procedure (e.g., atrial septal defect (ASD) requiring closure, high-risk patent foramen ovale (PFO) requiring closure, a highly mobile inter-atrial septal aneurysm precluding a safe TSP, presence of a PFO/ASD closure device, history of surgical ASD repair or history of surgical LAAO closure)
  • Atrial fibrillation that is defined by a single occurrence or that is transient or reversible (e.g., secondary thyroid disorders, acute alcohol intoxication, trauma, recent major surgical procedures)
  • A medical condition (other than atrial fibrillation) that mandates long-term oral anticoagulation (e.g., history of unprovoked deep vein thrombosis or pulmonary embolism, or prosthetic mechanical heart valve)
  • History of bleeding diathesis or coagulopathy, or patients in whom antiplatelet and/or anticoagulant therapy is contraindicated
  • Documented active systemic infection
Show all 30Show fewer
  • Symptomatic carotid artery disease (defined as >50% stenosis with symptoms of ipsilateral transient or visual TIA evidenced by amaurosis fugax, ipsilateral hemispheric TIAs or ipsilateral stroke); if subject has a history of carotid stent or endarterectomy the subject is eligible if there is <50% stenosis noted at the site of prior treatment
  • Recent (within 30 days of index procedure) or planned (within 60 days post-procedure) cardiac or major non-cardiac interventional or surgical procedure
  • Recent (within 30 days of index procedure) stroke or transient ischemic attack
  • Recent (within 30 days of index procedure) myocardial infarction
  • Vascular access precluding delivery of implant with catheter-based system
  • Severe heart failure (New York Heart Association Class IV)
  • Prior cardiac transplant, history of mitral valve replacement or transcatheter mitral valve intervention, or any prosthetic mechanical valve implant
  • Renal insufficiency, defined as estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 (by the Modification of Diet in Renal Disease equation)
  • Platelet count <75,000 cells/mm3 or >700,000 cells/mm3, or white blood cell count <3,000 cells/mm3
  • Known allergy, hypersensitivity or contraindication to aspirin, heparin, or that would preclude any P2Y12 inhibitor therapy, or to device materials (e.g., nickel, titanium), or the subject has contrast sensitivity that cannot be adequately pre-medicated
  • Actively enrolled or plans to enroll in a concurrent clinical study in which the active treatment arm may confound the results of this trial
  • Unable to undergo general anesthesia
  • Known other medical illness or known history of substance abuse that may cause non-compliance with the protocol or protocol-specified medication regimen, confound the data interpretation, or is associated with a life expectancy of less than 5 years
  • A condition which precludes adequate transesophageal echocardiographic assessment
  • Echo exclusion criteria:
  • Left atrial appendage anatomy which cannot accommodate a commercially available control device or the CLAAS Implant per manufacturer IFU (e.g., the anatomy and sizing must be appropriate for both the investigational (CLAAS) and a commercially available device in order to be enrolled in the trial)
  • Intracardiac thrombus or dense spontaneous echo contrast consistent with thrombus, as visualized by TEE
  • Left ventricular ejection fraction (LVEF) <30%
  • Moderate or large pericardial effusion >10 mm or symptomatic pericardial effusion, signs or symptoms of acute or chronic pericarditis, or evidence of tamponade physiology
  • Atrial septal defect that warrants closure
  • High risk patent foramen ovale (PFO), defined as an atrial septal aneurysm (excursion >15 mm or length > 15 mm) or large shunt (early [within 3 beats] and/or substantial passage of bubbles, e.g., >20)
  • Moderate or severe mitral valve stenosis (mitral valve area <1.5 cm2)
  • Complex atheroma with mobile plaque of the descending aorta and/or aortic arch
  • Evidence of cardiac tumor

Trial locations and contacts

94 sites in 6 countries.

94 sites in 6 countries

United States79 sites

  • Albany Medical Center / Capital Cardiology Associates

    Albany, New York, 12208

  • New Mexico Heart Institute

    Albuquerque, New Mexico, 87102

  • Mission Hospital

    Asheville, North Carolina, 28801

  • Piedmont Health Institute

    Atlanta, Georgia, 30309

  • Emory University

    Atlanta, Georgia, 30342

  • Northside Hospital, Inc

    Atlanta, Georgia, 30342

  • Medstar Union Memorial Hospital

    Baltimore, Maryland, 21218

  • Johns Hopkins University

    Baltimore, Maryland, 21287

  • Grandview Medical Center

    Birmingham, Alabama, 35243

  • Hartford Health Care St. Vincent's Medical Center

    Bridgeport, Connecticut, 06606

  • Deborah Heart and Lung

    Browns Mills, New Jersey, 08015

  • University of Buffalo / Kaleida Health

    Buffalo, New York, 14203

  • Lahey Hospital & Medical Centeer

    Burlington, Massachusetts, 01805

  • Erlanger Health System

    Chattanooga, Tennessee, 37403

  • TriHealth

    Cincinnati, Ohio, 45242

  • Prisma Health

    Columbia, South Carolina, 29203

  • Ohio Health Research Institute

    Columbus, Ohio, 43214

  • Henry Ford St. John Hospital

    Detroit, Michigan, 48236

  • Corewell Health

    Grand Rapids, Michigan, 49503

  • Bellin Health

    Green Bay, Wisconsin, 54301

  • Hackensack University Medical Center

    Hackensack, New Jersey, 07601

  • Cooper University - Heart House

    Haddon Heights, New Jersey, 08104

  • Terrebone - Cardiovascular Institute of the South

    Houma, Louisiana, 70360

  • Houston Methodist

    Houston, Texas, 77030

  • Memorial Hermann Memorial City Medical Center

    Houston, Texas, 77094

  • Ascension St. Vincent - Carmel, IN

    Indianapolis, Indiana, 46260

  • University of Iowa

    Iowa City, Iowa, 52242

  • Ascension St. Vincent's Jacksonville

    Jacksonville, Florida, 32204

  • St. Bernard's Medical Center

    Jonesboro, Arkansas, 72401

  • University of Kansas Medical Center

    Kansas City, Kansas, 66160

  • Saint Luke's Hospital of Kansas City

    Kansas City, Missouri, 64111

  • Tennova Healthcare - Turkey Creek Medical Center

    Knoxville, Tennessee, 37934

  • Largo Medical Center

    Largo, Florida, 33770

  • South Denver Cardiology Associates

    Littleton, Colorado, 80120

  • Loma Linda University Health

    Loma Linda, California, 92354

  • Catholic Medical Center

    Manchester, New Hampshire, 03102

  • M Health Fairview St. John's Hospital

    Maplewood, Minnesota, 55109

  • WellStar Kennestone Hospital

    Marietta, Georgia, 30062

  • UPMC Harrisburg

    Mechanicsburg, Pennsylvania, 17050

  • Baptist Hospital of Miami

    Miami, Florida, 33176

  • West Virginia University

    Morgantown, West Virginia, 26506

  • HCA Grand Strand

    Myrtle Beach, South Carolina, 29572

  • Midwest Cardiovascular Institute

    Naperville, Illinois, 60540

  • Vanderbilt University Medical Center

    Nashville, Tennessee, 37232

  • Mount Sinai Hospital

    New York, New York, 10029

  • Sentara Norfolk

    Norfolk, Virginia, 23507

  • Trident Medical Center

    North Charleston, South Carolina, 29406

  • CHI Health / CommonSpirit Research Institute

    Omaha, Nebraska, 68124

  • University of Nebraska Medical Center

    Omaha, Nebraska, 68198

  • AdventHealth Orlando

    Orlando, Florida, 32803

  • Kansas City Cardiac Arrhythmia Research, LLC

    Overland, Missouri, 66211

  • Huntington Hospital

    Pasadena, California, 91105

  • Baptist Health Care - Pensacola

    Pensacola, Florida, 32503

  • Banner University Medical Center Phoenix

    Phoenix, Arizona, 85006

  • Abrazo Arizona Heart Hospital

    Phoenix, Arizona, 85016

  • Arizona Heart Arrhythmia Associates

    Phoenix, Arizona, 85018

  • Baylor Scott & White Research Institute

    Plano, Texas, 75093

  • Lifespan Health System

    Providence, Rhode Island, 02903

  • Virginia Commonwealth University

    Richmond, Virginia, 23219

  • Chippenham Hospital

    Richmond, Virginia, 23225

  • Carilion Clinic

    Roanoke, Virginia, 24014

  • CentraCare Heart and Vascular Center

    Saint Cloud, Minnesota, 56303

  • Pacific Heart Institute

    Santa Monica, California, 90405

  • Sarasota Memorial Health Care System

    Sarasota, Florida, 34239

  • HonorHealth

    Scottsdale, Arizona, 85258

  • Virginia Mason Medical Center

    Seattle, Washington, 98101

  • Henry Ford Providence Southfield Hospital

    Southfield, Michigan, 48075

  • Baystate Medical Center

    Springfield, Massachusetts, 01199

  • AdventHealth Tampa

    Tampa, Florida, 33613

  • USF - Tampa General Hospital

    Tampa, Florida, 33620

  • ProMedica Toledo Hospital

    Toledo, Ohio, 43606

  • Pima Heart & Vascular

    Tucson, Arizona, 85719

  • North Mississippi Medical Center

    Tupelo, Mississippi, 38801

  • CHRISTUS Health

    Tyler, Texas, 75701

  • Community Memorial Hospital Ventura

    Ventura, California, 93003

  • MedStar Washington Hospital Center

    Washington D.C., District of Columbia, 20010

  • Lexington Medical Center

    West Columbia, South Carolina, 29169

  • Cardiovascular Research Institute of Kansas

    Wichita, Kansas, 67226

  • Lankenau Heart Institute

    Wynnewood, Pennsylvania, 19096

Other trials in United States

France5 sites

  • CHU de Bordeaux

    Bordeaux, 33604

  • CHU La Timone, Marseille

    Marseille, 13005

  • Institut Cardiovasculaire Paris Sud

    Massy, 91300

  • CHU de Toulouse

    Toulouse, 31059

  • Clinique Pasteur, Toulouse

    Toulouse, 31076

Other trials in France

Georgia4 sites

  • Chapidze Heart Disease Center

    Tbilisi

  • Israeli-Georgian Medical Research Clinic Helsicore

    Tbilisi

  • Tbilisi Heart and Vascular Clinic

    Tbilisi

  • Tbilisi Heart Center

    Tbilisi

Other trials in Georgia

Germany3 sites

  • Elisabeth Krankenhaus

    Essen, 45138

  • Cardiovasculäres Centrum Frankfurt

    Frankfurt, 60389

  • Asklepios Klinik-Altona

    Hamburg, 22763

Other trials in Germany

Uzbekistan2 sites

  • Republican Specialized Center for Surgery named after V. Vakhidov

    Chilanzar, Tashkent, 100115

  • AKFA Medline

    Olmazor, Tashkent, 100211

Other trials in Uzbekistan

Czechia1 site

  • Nemocnice Na Homolce

    Prague, 150 00

Other trials in Czechia

About this study

Official title: An Evaluation of the Safety and Effectiveness of the Conformal CLAAS System for Left Atrial Appendage Occlusion

The CLAAS® device will be evaluated for safety and efficacy by establishing its performance is non-inferior to the commercially available WATCHMAN® and Amulet™ left atrial appendage closure devices in patients with non-valvular atrial fibrillation. Patients who are eligible for the trial will be randomized to receive either the CLAAS device or the WATCHMAN or Amulet™ devices and will be followed for 5 years after device implant.

Being tested
CLAAS, WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder
Medical subject headings
Atrial Fibrillation, Stroke

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • CLAASDevice

    CLAAS

  • WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluderDevice

    WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder

Study groups in NCT05147792
Study groupRoleWhat they receive
CLAASExperimentalTranscatheter left atrial occluder
Receives: Device: CLAAS
WATCHMAN / AmuletActive comparatorTranscatheter left atrial occluder
Receives: Device: WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder

What is being measured

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

  1. Procedure-related complications, all-cause death, major bleeding

    The primary safety endpoint is a composite of 1) major procedure-related complications including a) cardiac perforation, b) pericardial effusion requiring drainage, c) ischemic stroke, d) device embolization, and e) major vascular complications, or 2) major bleeding, or 3) all-cause death

    Measured: 12 months

  2. Ischemic stroke and systemic embolism

    The primary effectiveness endpoint is a composite of ischemic stroke and systemic embolism through 18 months.

    Measured: 18 months

Secondary outcomes (6)

  1. Procedure-related complications, all-cause death, major bleeding

    All elements of the Primary Safety Endpoint will be reported descriptively for all subjects through 5 years: a composite of 1) major procedure-related complications including a) cardiac perforation, b) pericardial effusion requiring drainage, c) ischemic stroke, d) device embolization, and e) major vascular complications, or 2) major bleeding, or 3) all-cause death

    Measured: 5 years

  2. Device Success

    A secondary performance and efficacy endpoint is Device Success, defined as LAAO device deployed and implanted in correct position

    Measured: Procedure

  3. Technical success

    A secondary performance and efficacy endpoint is Technical Success, defined as Device Success, complete closure or peri-device residual leak ≤5 mm in width on TEE, as evaluated by independent imaging core lab without device-related complications [evaluated post-procedure].

    Measured: 45 days

  4. Procedure success

    A secondary performance and efficacy endpoint is Procedure Success, defined as Technical Success without in-hospital major procedure-related complications (excluding minor device embolization) evaluated at hospitalization or at 7 days whichever is first.

    Measured: 7 Days

  5. Embolic Events

    A secondary performance and efficacy endpoint is Embolic Events, defined as ischemic stroke as defined by NeuroARC (29) and systemic thromboembolism characterized as any thromboemboli in the arterial system.

    Measured: 12 Months, 18 Months

  6. Closure Success

    A secondary performance and efficacy endpoint is Closure Success at 12 months based upon each of the following criteria: a) demonstration of peri-device leak </=5 mm, and b) demonstration of peri-device leak </=3 mm

    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 posted7 Dec 2021
  2. Study start26 May 2022
  3. Primary completionJun 2028 (estimated)
  4. Study completionDec 2031 (estimated)

Why it stopped: Enrollment has been temporarily suspended out of an abundance of caution and in close consultation with trial leadership and regulatory bodies to review overall study data thoroughly following a serious adverse event.

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 N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
1,600 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05147792
Sponsor's protocol ID
21-101
Status last verified
Aug 2026
First submitted
24 Nov 2021
Last updated
25 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing CLAAS and WATCHMAN left atrial appendage closure device / Amulet left atrial appendage occluder in people with Atrial Fibrillation and Stroke, run by Conformal Medical, Inc at 94 sites in 6 countries.

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 8 inclusion and 30 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: paused, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 94 sites in United States, France, Georgia, Germany, Uzbekistan and 1 more country. 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?

Results are not available in the source record.

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?

Procedure-related complications, all-cause death, major bleeding (time frame: 12 months). The study lists 2 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 NCT05147792.

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 25 Sep 2026.

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The CONFORM Pivotal Trial (NCT05147792) | AzTrials