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Atrial Fibrillation (AF)Conquer-AFNCT07298473

Conquer-AF Protocol for Redo Ablation Procedures in Recurrent Paroxysmal and Persistent Atrial Fibrillation Using the Sphere-9 Catheter and Affera Ablation System (Conquer-AF)

A study testing Sphere-9 Catheter Ablation in people with Atrial Fibrillation (AF) and Persistent Atrial Fibrillation, run by Medtronic Cardiac Ablation Solutions at 30 sites in 6 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

Conquer-AF is a prospective, multi-center, interventional, non-randomized clinical study that will enroll up to 400 subjects at up to 30 sites across the United States, Europe, and Australia. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
Sphere-9 Catheter Ablation
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
400 participants
Where
30 sitesin 6 countries
Study dates
8 Apr 2026to 29 Mar 2028
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

  • 1. History of a single AF ablation procedure for PAF or PsAF within 3 years prior to enrollment 2. Documented evidence of symptomatic AF, AT or AFL recurrence at least 90 days after subject's de novo ablation procedure, as demonstrated by:
  • A physicians' note indicating at least 1 symptomatic AF, AT, or AFL episode occurring within 12 months prior to the enrollment; and
  • At least 1 electrocardiographically documented episode of AF, AT, or AFL within 12 months prior to enrollment 3. Adults who are ≥18 years of age on the day of enrollment 4. Willing and able to comply with all study requirements and provide informed consent

Who cannot join

  • 1. Continuous AF lasting for 12 months or longer 2. LA anteroposterior >55 mm (by MRI, CT, or TTE), or if LA diameter not available, non-index volume >100 mL for PsAF subjects; OR LA anteroposterior >50 mm (by MRI, CT, or TTE), or if LA diameter not available, non-index volume >95 mL for PAF subjects 3. Previous left atrial percutaneous interventions including left atrial appendage occlusion and septal closure devices 4. Planned left atrial appendage (LAA) closure procedure, cardiac transplantation or implant of a permanent pacemaker, biventricular pacemaker, loop recorder/insertable cardiac monitor (ICM), or any type of implantable cardiac defibrillator (with or without biventricular pacing function) for any time during the follow-up period 5. More than 1 previous AF ablation procedure 6. Any prior surgical ablation procedure 7. Patient who is not on oral anticoagulation therapy for at least 3 weeks prior to the ablation procedure 8. Contraindication to or unwillingness to use systemic anticoagulation 9. Severe thrombocytosis, thrombocytopenia, or any bleeding or clotting disorder 10. Presence of a permanent pacemaker, biventricular pacemaker, loop recorder/insertable cardiac monitor (ICM), or any type of implantable cardiac defibrillator (with or without biventricular pacing function) 11. Presence of any pulmonary vein stents 12. Known pre-existing pulmonary vein stenosis 13. Pre-existing hemidiaphragmatic paralysis 14. Prior valvular (surgical or percutaneous) procedure including prosthetic, bioprosthetic, valve replacement, valve repair or valvuloplasty, or any prior atriotomy 15. Moderate to severe mitral valve or aortic stenosis 16. Moderate to severe mitral regurgitation (i.e., 3+ or 4+ MR) 17. Any cardiac surgery, myocardial infarction, PCI/PTCA or coronary artery stenting which occurred within the 3 months preceding the consent date 18. NYHA Class III or IV congestive heart failure 19. Documented left ventricular ejection fraction (LVEF) ≤40%, measured by acceptable cardiac testing (e.g., TTE) 20. Unstable angina 21. Severe lung disease, primary pulmonary hypertension, or any lung disease requiring supplemental oxygen 22. Rheumatic heart disease 23. Significant restrictive or obstructive pulmonary disease or chronic respiratory condition 24. Presence of left atrial thrombus on imaging 25. Active systemic infection or sepsis 26. Hypertrophic cardiomyopathy 27. Amyloid heart disease 28. Diagnosed atrial myxoma 29. Known reversible causes of AF (e.g., uncontrolled hyperthyroidism, severe untreated obstructive sleep apnea, acute alcohol toxicity or other reversible or non-cardiac cause) 30. Any cerebral ischemic event (strokes or TIAs) which occurred within the preceding 6 months of the consent date through the date of study index redo ablation procedure 31. Carotid stenting or endarterectomy 32. Thromboembolic event within the past 6 months or evidence of intracardiac thrombus at the time of the procedure 33. Body mass index > 40 kg/m2 34. Any woman known to be pregnant or breastfeeding, or any woman of childbearing potential who is not on a reliable form of birth regulation method or abstinence* 35. Patient with life expectancy that makes it unlikely 12 months of follow-up will be completed 36. Current or anticipated participation in any other clinical study of a drug, device or biologic during the duration of the study not pre-approved by Medtronic 37. Renal insufficiency with an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2, or any history of renal failure requiring dialysis or renal transplant 38. Presence of intramural thrombus, tumor, or other abnormality that precludes vascular access, catheter introduction, or manipulation 39. Presence of an inferior vena cava (IVC) filter (e.g., Greenfield or similar) that would preclude safe transfemoral venous access, catheter passage, or sheath manipulation.
  • 40. Known drug or alcohol dependency 41. Significant congenital anomaly or medical problem that would, in the opinion of the investigator, preclude enrollment, follow-up compliance, or the scientific integrity of the study
  • Women who are of child-bearing potential must undergo a pregnancy test after consent and prior to the study index redo ablation procedure, as allowed according to local regulations

Trial locations and contacts

30 sites in 6 countries. Contact the study team or a site near you to ask about taking part.

Ryan S Radtke, Bachelors of Science- Biology contact

712-941-9372

ryan.s.radtke@medtronic.com

30 sites in 6 countries

United States22 sites, 22 recruiting

  • Piedmont Heart Institute

    Atlanta, Georgia, 30309

    Sandeep Goyal, 404-605-5000, sandeep.goyal@piedmont.org

    Sandeep Goyal, MD

    Recruiting

  • University of Alabama at Birmingham (UAB) Hospital

    Birmingham, Alabama, 35233

    Hugh Thomas McElderry, (205) 934-2525, tommcelderry@uabmc.edu

    Hugh Thomas McElderry, MD

    Recruiting

  • Massachusetts General Hospital

    Boston, Massachusetts, 02114-2621

    Moussa Mansour, (617) 726-2928, mmansour@mgh.harvard.edu

    Moussa Mansour, MD

    Recruiting

  • Cleveland Clinic Foundation

    Cleveland, Ohio, 44195

    Ayman Hussein, (216) 444-6697, husseia@ccf.org

    Ayman Hussein, MD

    Recruiting

  • OhioHealth Research and Innovation Institute (OHRI)

    Columbus, Ohio, 43214-3467

    Anish Amin, (614) 262-6772, anish.amin@ohiohealth.com

    Anish Amin, MD

    Recruiting

  • Texas Cardiac Arrhythmia Research Foundation

    Dallas, Texas, 75226

    Andrea Natale, (512) 807-3150, tcarfan@gmail.com

    Andrea Natale, MD

    Recruiting

  • Inova Fairfax Hospital

    Falls Church, Virginia, 22042

    Stephen Gaeta, 703-776-4001, stephen.gaeta@inova.org

    Stephen Gaeta, MD

    Recruiting

  • Texas Health Fort Worth

    Fort Worth, Texas, 76104

    Theodore Takata, 817-250-2000, theodoretakata@texashealth.org

    Theodore Takata, MD

    Recruiting

  • Kansas City Heart Rhythm Institute (Midwest Heart and Vascular Specialist)

    Kansas City, Missouri, 64111

    Dhanunjaya Lakkireddy, 816-276-4000, dhanunjaya.lakkireddy@hcahealthcare.com

    Dhanunjaya Lakkireddy, MD

    Recruiting

  • Scripps Green Hospital

    La Jolla, California, 92037

    Douglas Gibson, (858) 455-9100, gibson.douglasmd@scrippshealth.org

    Douglas Gibson, MD

    Not yet recruiting

  • Cedars Sinai Medical Center

    Los Angeles, California, 90048-1804

    Michael Shehata, 310-423-3277, michael.shehata@cshs.org

    Michael Shehata, MD

    Recruiting

  • Centra Medical Group Stroobants Cardiovascular Center

    Lynchburg, Virginia, 24501

    Chinmaya Mareddy, 434-200-3000, chinmaya.mareddy@centrahealth.com

    Chinmaya Mareddy, MD

    Recruiting

  • NCH Rooney Heart Institute

    Naples, Florida, 34102

    Dinesh Sharma, 239-624-5000, dinesh.sharma@nchmd.org

    Dinesh Sharma, MD

    Recruiting

  • Vanderbilt University Medical Center

    Nashville, Tennessee, 37232-0019

    Zachary Yoneda, (615) 457-7391, zachary.t.yoneda@vumc.org

    Zachary Yoneda, MD

    Recruiting

  • Northwell Health Lenox Hill Hospital

    New Hyde Park, New York, 11040-1402

    Haisam Ismail, (718) 470-7330, hismail@northwell.edu

    Haisam Ismail, MD

    Recruiting

  • NYU Langone Health

    New York, New York, 10016-4972

    Larry Chinitz, 212-263-7300, larry.chinitz@nyulangone.org

    Larry Chinitz, MD

    Recruiting

  • Sentara Norfolk General Hospital

    Newport News, Virginia, 23606-2981

    Venkat Iyer, (757) 499-2825, viyer@cval.org

    Venkat Iyer, MD

    Recruiting

  • AdventHealth Cardiovascular Research Institute

    Orlando, Florida, 32803

    Usman Siddiqui, 407-303-5600, siddiqui.u@gmail.com

    Usman Siddiqui, MD

    Recruiting

  • Hospital of the University of Pennsylvania

    Philadelphia, Pennsylvania, 19104

    Saman Nazarian, (215) 615-5220, saman.nazarian@pennmedicine.upenn.edu

    Saman Nazarian, MD

    Recruiting

  • Allegheny General Hospital

    Pittsburgh, Pennsylvania, 15212-4756

    Amit Thosani, (412) 310-6711, amit.thosani@ahn.org

    Amit Thosani, MD

    Recruiting

  • Memorial Health University Medical Center

    Savannah, Georgia, 31404

    Todd Senn, 912-350-8000, todd.senn@hcahealthcare.com

    Todd Senn, MD

    Recruiting

  • Montefiore Medical Center

    The Bronx, New York, 10467

    Luigi Di Biase, (718) 920-4116, ldibiase@montefiore.org

    Luigi Di Biase, MD

    Recruiting

Other trials in United States

Australia3 sites, 3 recruiting

  • Adelaide University

    Adelaide, South Australia, 5000

    Prashanthan Sanders, +61 882222723, prash.sanders@adelaide.edu.au

    Sanders Prashanthan, MD

    Recruiting

  • The Royal Melbourne Hospital

    Parkville, Victoria, 3050

    Jonathan M Kalman, +61 393495400, jon.kalman@mh.org.au

    Jonathan M Kalman, MD

    Recruiting

  • Westmead Hospital

    Westmead, New South Wales, 2145

    Stuart Thomas, 61 2 8890 5555, stuart.thomas@sydney.edu.au

    Stuart Thomas, MD

    Recruiting

Other trials in Australia

Czechia2 sites, 2 recruiting

  • IKEM - Institut Klinické a Experimentální Medicíny

    Prague, 140 21

    Josef Kautzner, +420 261365006, josef.kautzner@ikem.cz

    Josef Kautzner, MD

    Not yet recruiting

  • Motol and Homolka University Hospital

    Prague, 150 30

    Petr Neuzil, +420 257272211, pneuzil@seznam.cz

    Petr Neuzil, MD

    Not yet recruiting

Other trials in Czechia

Belgium1 site, 1 recruiting

  • Universitair Ziekenhuis Brussel

    Brussels, 1090

    Andrea Sarkozy, +32 24774111, andrea.sarkozy@uzbrussel.be

    Andrea Sarkozy, MD

    Not yet recruiting

Other trials in Belgium

France1 site, 1 recruiting

  • Clinique Pasteur

    Toulouse, 31076

    Jean-Paul Albenque, +33 562211645, j.albenque@clinique-pasteur.com

    Jean-Paul Albenque, MD

    Not yet recruiting

Other trials in France

Switzerland1 site, 1 recruiting

  • Inselspital - Universitätsspital Bern

    Bern, 3010

    Tobias Reichlin, +41 316640050, tobias.reichlin@insel.ch

    Tobias Reichlin, MD

    Not yet recruiting

Other trials in Switzerland

About this study

Conquer-AF is a prospective, multi-center, interventional, non-randomized clinical study that will enroll up to 400 subjects at up to 30 sites across the United States, Europe, and Australia.

Subjects diagnosed with symptomatic recurrent paroxysmal or persistent atrial fibrillation after a single prior ablation procedure will be enrolled in this study. Each subject will undergo a study index redo ablation procedure using the Sphere-9 Catheter and Affera Ablation System and will be followed for 12 months. The expected total study duration (from time of first enrollment to the exit of last enrolled subject) is approximately 2 years.

Read the detailed description

The Conquer-AF study is a prospective, multi-center, interventional, non-randomized clinical study to evaluate the safety and effectiveness of the Sphere-9 Catheter and Affera Ablation System, when used in conjunction with the Affera Mapping System or Affera Integrated Mapping System, in patients undergoing redo ablation for symptomatic recurrent paroxysmal or persistent atrial fibrillation following a single prior ablation procedure.

This study will enroll up to 400 subjects diagnosed with symptomatic recurrent PAF and PsAF and will be conducted at up to 30 study sites located across the United States, Europe, and Australia. No single site may enroll more than 60 (with no more than 37 in either cohort) subjects to ensure a reasonable distribution of subjects across sites.

Adult subjects with symptomatic recurrent PAF and PsAF will undergo a study index redo ablation procedure with the Sphere-9 Catheter and Affera Ablation System. Following the study index redo ablation procedure and hospital discharge, all study subjects will be followed at 7 days, 3 months, 6 months, and 12 months post-procedure. Subjects will be exited from the study at the conclusion of the 12-month follow-up visit and associated 24-hour Holter. The expected total study duration is approximately 2 years, representing approximately 12 months of enrollment and 12 months of subject follow-up. Treated subjects will not be replaced with newly enrolled subjects upon early study exit.

Being tested
Sphere-9 Catheter Ablation
Keywords
Sphere-9 Catheter, Affera Ablation System, Affera Mapping System, Pulsed Field Ablation (PFA), Radiofrequency Ablation (RFA), Dual-Energy Ablation, Atrial Fibrillation, Paroxysmal Atrial Fibrillation, Persistent Atrial Fibrillation, Redo Ablation, Repeat Ablation, Electrophysiology Mapping, 3D Cardiac Mapping, Left Atrial Ablation, Redo AF Ablation, Repeat Ablation Procedures
Medical subject headings
Atrial Fibrillation

What participants receive

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

  • Sphere-9 Catheter AblationDevice

    Also called Affera Ablation System, Affera Mapping System

    Redo atrial fibrillation ablation performed using the Sphere-9 Catheter in conjunction with the Affera Ablation System and Affera Mapping System. The intervention delivers radiofrequency and pulsed field energy according to the study protocol for treatment of recurrent paroxysmal or persistent AF. All participants receive this device-based ablation procedure.

Study groups in NCT07298473
Study groupRoleWhat they receive
Single Arm: Redo AF Ablation with Sphere-9 CatheterExperimentalParticipants undergo a redo atrial fibrillation ablation using the Sphere-9 Catheter and the Affera Ablation System per study protocol. All subjects receive the same intervention with no control or comparator arm.
Receives: Device: Sphere-9 Catheter Ablation

What is being measured

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

  1. Effectiveness: Number of Participants With Treatment Success.

    Treatment success is defined to be freedom from treatment failure. The study requires 24-hour Holter monitoring at 6 and 12 months, weekly and symptomatic patient activated TTM transmissions through 12 months, and 12-lead ECGs or TTMs at all follow up visits. Treatment failure is defined as any of the following components:

    • Inability to successfully complete the study index redo ablation procedure utilizing the Sphere-9 Catheter and Affera Ablation System exclusively
    • Documented AF/AT/AFL after the 90-day post-ablation blanking period
    • Any subsequent catheter or surgical ablation, for recurrent AF/AT/AFL including repeat redo ablation at any time during the study
    • Direct current or pharmacological cardioversion for AF/AT/AFL recurrences after the 90-day blanking period (See section 9.11)
    • Use of a Class I or III AAD at a higher daily dose than the pre-ablation maximum dose after the 90-day blanking period and on or before day 365.
    • Initiation of a new Class I or III AAD after t

    Measured: 12-months post-redo ablation procedure

  2. Safety: Number of Participants With at Least One Primary Safety Event

    Primary safety events include:

    • 7 days of post-ablation: AKI requiring dialysis, new hospitalization >48 hours, or prolongation of hospitalization >48 hours beyond expected discharge, Death, Heart block requiring pacemaker, Major bleeding requiring transfusion, MI, Permanent phrenic nerve paralysis, Pulmonary edema, Severe pericarditis, Significant pericardial effusion/tamponade, Stroke/CVA, Systemic/pulmonary embolism requiring intervention, TIA, Vagal nerve injury resulting in esophageal dysmotility or gastroparesis, Vascular access complications requiring intervention, Any Sphere-9 Catheter or Affera Mapping \& Ablation System device- or procedure-related cardiovascular and/or pulmonary AE that prolongs or requires hospitalization >48 hours (excl recurrent AF/AT/AFL)
    • 3 months post-ablation: Atrioesophageal fistula/esophago-pericardial fistula, Esophageal perforation (procedure \& Sphere-9 Catheter related)
    • 6 months post-ablation: Pulmonary vein stenosis (≥70% diameter reduction)

    Measured: 6-months post-redo ablation procedure

Timeline

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

  1. First posted23 Dec 2025
  2. Study start8 Apr 2026
  3. Primary completion29 Mar 2028 (estimated)
  4. Study completion29 Mar 2028 (estimated)

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
Treatment
Allocation
Not applicable
Intervention model
Single group
Model description
This is a prospective, multi-center, single-arm study in which all enrolled participants undergo a redo atrial fibrillation ablation using the Sphere-9 Catheter and Affera Ablation System. There is no randomization or control groups. All subjects who have the Sphere-9™ Catheter inserted into the vasculature are included in the Primary Analysis Group. Subjects who exit the study prior to catheter insertion are classified as non-treated and are not included in the primary analysis.
Masking
None (open label)
Enrolment
400 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07298473
Sponsor's protocol ID
MDT25005
Acronym
Conquer-AF
Status last verified
Apr 2026
First submitted
19 Dec 2025
Last updated
19 Oct 2026
Results posted
No
Data monitoring committee
No
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 Sphere-9 Catheter Ablation in people with Atrial Fibrillation (AF) and Persistent Atrial Fibrillation, run by Medtronic Cardiac Ablation Solutions at 30 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 3 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 19 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 30 sites in United States, Australia, Czechia, Belgium, France 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?

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 Ryan S Radtke, Bachelors of Science- Biology (712-941-9372, ryan.s.radtke@medtronic.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Effectiveness: Number of Participants With Treatment Success. (time frame: 12-months post-redo ablation procedure). 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 NCT07298473.

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 19 Oct 2026.

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