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Atrial FibrillationPARALELLNCT05408754

Pulsed Field Ablation and Pulsed Field CRyoAbLation in PErsistent AtriaL FibrilLation

A study testing Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF. in people with Atrial Fibrillation, run by Adagio Medical at 6 sites in 6 countries.

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

A prospective, two-arm, multi-center, randomized, open-label, pre-market, First-in-Human clinical study designed to provide safety and performance data regarding the use of the Adagio PFA and PFCA Systems in the treatment of PsAF. Read more about this study

Who is it for?
Ages 18 to 80 years
Conditions the study is for
Atrial Fibrillation
What is being tested?
Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF.
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
89 participants
Where
6 sitesin 6 countries
Study dates
20 Oct 2022to 3 Mar 2025
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 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • IC 1 Male or female between the ages of 18 - 80 years
  • IC 2 Currently scheduled for an ablation of symptomatic persistent (> 7 days) atrial fibrillation within the past year documented by ECG or Continuous Holter monitoring
  • IC 3 Refractory to at least one class I or III AAD. (Refractory defined as not effective or not tolerated)
  • IC 4 Willingness, ability, and commitment to participate in baseline and follow-up evaluations for the full length of the study
  • IC 5 Willingness and ability to give an informed consent

Who cannot join

  • EC 1 In the opinion of the Investigator, any known contraindication to an atrial ablation, TEE, or anticoagulation. Including but not limited to the identification of any atrial thrombus or evidence of sepsis
  • EC 2 Continuous AF lasting longer than 12-months
  • EC 3 History of previous left atrial ablation or surgical treatment for AF/AFL/AT
  • EC 4 AF secondary to electrolyte imbalance, active thyroid disease, or any other reversible or non-cardiac cause
  • EC 5 Structural heart disease as described below:
  • Left ventricular ejection fraction (LVEF) < 40% based on most recent TTE
Show all 30Show fewer
  • Left atrial size > 55 mm (parasternal long axis view) documented within 6-months of screening
  • NYHA Class III or IV heart failure documented within the previous 12-months
  • An implanted pacemaker or ICD
  • Previous cardiac surgery, ventriculotomy, or atriotomy (excluding atriotomy for CABG),
  • Previous cardiac valvular surgical or percutaneous procedure, or prosthetic valve
  • Interatrial baffle, closure device, patch, or PFO occluder
  • Presence of a left atrial appendage occlusion device
  • Presence of any pulmonary vein stenting devices
  • Coronary artery bypass graft (CABG) or PTCA procedure within six (6) months prior to procedure
  • Unstable angina or ongoing myocardial ischemia
  • Myocardial infarction within the previous six (6) months prior to procedure
  • Moderate or severe mitral insufficiency or stenosis based on most recent TTE
  • Atrial myxoma
  • Significant congenital anomaly
  • EC 6 BMI > 40
  • EC 7 Any previous history of cryoglobulinemia (for those patients randomized to the PFCA arm)
  • EC 8 History of blood clotting or bleeding disease
  • EC 9 History of severe COPD requiring steroid use in the previous 12-months
  • EC 10 History of severe sleep apnea (AHI > 30) not currently treated with a CPAP machine or other mechanical device
  • EC 11 Stroke or TIA within the last year.
  • EC 12 Any prior history or current evidence of hemidiaphragmatic paralysis
  • EC 13 Pregnant or lactating (current or anticipated during study follow-up
  • EC 14 Current enrollment in any other study protocol where testing or results from that study may interfere with the procedure or outcome measurements for this study
  • EC 15 Any other conditions such as, mental illness, addictive disease, terminal illness with a life expectancy of less than two years, extensive travel away from the research center that may lead to non-compliance with the protocol procedure or follow up

Trial locations and contacts

6 sites in 6 countries.

6 sites in 6 countries

Belgium1 site
  • Onze-Lieve-Vrouwziekenhuis (OLV)

    Aalst, B-9300

Other trials in Belgium

Canada1 site
  • McGill University Health Centre (MUHC), Montreal General Hospital (MGH)

    Montreal, Quebec, H3G 1A4

Other trials in Canada

Czechia1 site
  • Nemocnice Na Homolce

    Prague, 150 30

Other trials in Czechia

Ireland1 site
  • Blackrock Health

    Dublin, A94 E4X7

Other trials in Ireland

Netherlands1 site
  • St Antonius Ziekenhuis

    Nieuwegein, 3435

Other trials in Netherlands

United Kingdom1 site
  • St George'S University Hospital

    London, SW17 0QT

Other trials in United Kingdom

About this study

Official title: PARALELL - Pulsed Field Ablation and Pulsed Field CRyoAbLation in PErsistent AtriaL FibrilLation

A prospective, two-arm, multi-center, randomized, open-label, pre-market, First-in-Human clinical study designed to provide safety and performance data regarding the use of the Adagio PFA and PFCA Systems in the treatment of PsAF.

Read the detailed description

Enrolled subjects will be treated (ablation) with the Adagio PFA or PFCA System in a 1:1 randomized fashion.

Treatment will include the isolation of pulmonary veins (PVIs), and isolation of the left atrial posterior wall (PWI), and CTI at the discretion and clinical judgment of the investigator.

Data will be collected throughout 12-month follow up period to assess safety and performance of the device. Recurrence of atrial arrhythmias is measured by 12-lead ECGs and 48-hour continuous ECG recording (Holter).

Being tested
Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF.
Keywords
Pulsed Field Ablation, Pulsed Field CryoAblation, Persistent AF, PFA, PFCA, AF, Adagio Medical
Medical subject headings
Atrial Fibrillation

What participants receive

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

  • Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF.Device

    Treatment will include the isolation of pulmonary veins (PVIs), and isolation of the left atrial posterior wall (PWI). A right atrial cavo-tricuspid line for bi-directional block may be performed at discretion and clinical judgment of the investigator

Study groups in NCT05408754
Study groupRoleWhat they receive
Pulsed Field Ablation (PFA) groupExperimentalPsAF patients treated by PFA
Receives: Device: Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF.
Pulsed Field CryoAblation (PFCA) groupExperimentalPsAF patients treated by PFCA
Receives: Device: Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF.

What is being measured

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

  1. Primary Endpoint for Safety

    Analysis of the proportion of subjects who are free from device/procedure-related Major Adverse Events that occur during or following the ablation procedure

    Measured: Up to 7 days following the ablation procedure

  2. Primary Procedural Performance Outcome

    Analysis of the evidence of procedural electrical isolation of all pulmonary veins, posterior wall, and bidirectional block (if applicable) across all other ablation lines using the study device.

    Measured: Procedure

Secondary outcomes (8)
  1. One-Year Safety

    Recording and analysis of all identified serious adverse events and serious adverse device effects through 12 months post-procedure.

    Measured: 12 months

  2. One-Year Performance

    Proportion of subjects receiving a single ablation procedure who has freedom from any documented left atrial arrhythmia (AF/AFL/AT) lasting longer than 30 seconds following the Blanking Period (3-months ± 14-days post index ablation) using a continuous 48-hour ECG recording through 12 months post-procedure.

    Measured: 12 months

  3. Procedural Performance - ablation time

    Ablation time defined as the total time for energy delivery to achieve PVI, PWI, and CTI (if applicable)

    Measured: procedure

  4. Procedural Performance - procedure time

    Total procedure time defined as the time from first venous access to the removal of the catheters from the heart at the end of the procedure

    Measured: procedure

  5. Procedural Performance - fluoroscopy time

    Procedure fluoroscopy time

    Measured: procedure

  6. Procedural Performance - intraprocedural PV reconnection rate

    The rate of intraprocedural PV reconnection - defined as confirmed conduction across a PVI line during the 20-minute waiting period to confirm PVI

    Measured: procedure

  7. Procedural Performance - AAD use

    Recording of the use of AADs in the follow up period beyond a 90-day blanking period

    Measured: procedure and up to 12-month

  8. Procedural Performance - repeat ablation

    Number of repeat ablations within and following the blanking period

    Measured: procedure and up to 12-month

Timeline

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

  1. First posted7 Jun 2022
  2. Study start20 Oct 2022
  3. Primary completion14 Oct 2024
  4. Study completion3 Mar 2025

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
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
89 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05408754
Sponsor's protocol ID
CS-169
Acronym
PARALELL
Status last verified
Sep 2025
First submitted
2 Jun 2022
Last updated
13 Apr 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Atrial ablation for subject scheduled for a de novo endocardial ablation of symptomatic, drug-refractory PsAF. in people with Atrial Fibrillation, run by Adagio Medical at 6 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 5 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: finished, as of the sponsor's last update on 13 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in Belgium, Canada, Czechia, Ireland, Netherlands 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?

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?

Primary Endpoint for Safety (time frame: Up to 7 days following the 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?
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 13 Apr 2026.

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