Atrial Fibrillation (AF)CONSCIOUS-PFANCT07900685
A Comparison of Pulsed Field Ablation (PFA) vs Cryoablation for Atrial Fibrillation Under Deep Sedation
A study testing Catheter ablation, Deep sedation with midazolam and fentanyl or midazolam and remifentanil and Sedation with midazolam and fentanyl in people with Atrial Fibrillation (AF), run by East Sussex Healthcare NHS Trust at 1 site in United Kingdom.
Trial summary
Pulsed Field Ablation (PFA) has created a 'paradigm shift' within cardiac electrophysiology and the initial experience demonstrates that PFA is safe, rapid and effective compared to both radiofrequency ablation and cryoablation in atrial fibrillation (AF). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation (AF)
- What is being tested?
- Catheter ablation, Deep sedation with midazolam and fentanyl or midazolam and remifentanil and Sedation with midazolam and fentanyl
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 19 Oct 2026to 1 Oct 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
- Patients with paroxysmal or persistent AF requiring a clinically-indicated AF ablation
- Age >18 years old
- Able to give informed consent
Who cannot join
- Patients with a BMI >35
- Any patient with a history of airway issues/Obstructive sleep apnoea/ obesity hypoventilation syndrome
- Significant acid reflux or presence of a large hiatus hernia
- Lack of capacity to give informed consent
- Unable to lie flat for a minimum of 45 mins
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Eastbourne DGH
Eastbourne
Jo-Anne Taylor, x771439, esh-tr.researchanddevelopment@nhs.net
About this study
Pulsed Field Ablation (PFA) has created a 'paradigm shift' within cardiac electrophysiology and the initial experience demonstrates that PFA is safe, rapid and effective compared to both radiofrequency ablation and cryoablation in atrial fibrillation (AF). Presently, AF ablation procedures in the UK using PFA are routinely performed using general anaesthetic (GA) support requiring an anaesthetist and ODP being present in all procedures. This need significantly limits the ability to use PFA technology to perform AF ablations, particularly in centres that have limited availability of GA provision.
The need for GA also leads to extended patient recovery time post procedure which impacts patient throughput and has the potential to reduce hospital bed availability. The need for GA and the potential to limit patient throughput has negative implications for all hospitals in terms of cost. PFA procedures performed elsewhere in Europe use deep sedation with IV propofol led by the ablating physician, but this is not permitted in the UK and still requires the presence of an anaesthetist.
The investigators will aim to evaluate if AF ablation using PFA is feasible during spontaneous respiration without the use of propofol. The investigators will conduct a non-randomized study comparing AF ablation using PFA vs cryoballoon under deep sedation - aiming to demonstrate that >75% of patients can complete the PFA protocol under deep sedation without conversion to cryoballoon (due to patient intolerance). The principal aim of the study is therefore not to demonstrate superiority or comparative efficacy of one ablation modality over another but rather the ability and feasibility to deliver pulsed field ablation under deep sedation. The use of cryoablation serves as a benchmark comparator to contextualise procedural and sedation-related observations.
Read the detailed description
60 patients undergoing a clinically-indicated AF ablation procedure will be allocated in a 2:1 ratio to either receive PFA or cryoballoon. All procedures will be completed using deep sedation using intravenous fentanyl or remifentanil infusion and midazolam. Additionally, a bolus of intravenous lidocaine will be given to suppress the cough reflex during PFA applications. If a participant is unable to tolerate the procedure using PFA, the procedure will be converted to cryoballoon during the same sitting and completed as per standard clinical protocol. It is anticipated that general anaesthesia will not be required for any participants in the study.
If the study proves successful, this will provide a clear deep sedation protocol for use with PFA during pulmonary vein isolation with a view to reducing the need for GA cover and improve lab efficiency which has significant financial implications for NHS healthcare providers.
- Conditions
- Atrial Fibrillation (AF)
- Being tested
- Catheter ablation, Deep sedation with midazolam and fentanyl or midazolam and remifentanil, Sedation with midazolam and fentanyl
- Keywords
- ablation, atrial fibrillation, pulsed field ablation
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Catheter ablationDevice
Catheter ablation for AF
Deep sedation with midazolam and fentanyl or midazolam and remifentanilDrug
During ablation, sedation will be given with either midazolam and fentanyl or midazolam and remifentanil
Sedation with midazolam and fentanylDrug
Sedation using lower doses of midazolam and fentanyl
| Study group | Role | What they receive |
|---|---|---|
| Pulsed field ablation group under deep sedation | Experimental | Not described Receives: Device: Catheter ablation; Drug: Deep sedation with midazolam and fentanyl or midazolam and remifentanil |
| Cryoablation group under sedation | Active comparator | Not described Receives: Device: Catheter ablation; Drug: Sedation with midazolam and fentanyl |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of patients able to complete protocol with pulsed field ablation without conversion to cryoablaton
Target is 75% of patients
Measured: 18 months
Secondary outcomes (3)
Numeric Rating scale for pain - Pain severity index (PSI)
0-10 (high score = more pain) - comparison of pain scores between PFA and cryoablation
Measured: 18 months
- Patient Experience Questionnaire for post-procedural pain, discomfort - Visual Analogue Scale (VAS) - Atrial Fibrillation Specific Patient Reported Outcome Measures Questionnaire (AF-PROMs) questionnaire
Patients mark with an X on a visual analogue scale how much pain/discomfort they experienced (0-10) - 10 being more pain; comparison of numerical scores between pulsed field ablation and cryoablation
Measured: 18 months
- Lab occupancy time/ skin-to-skin time
Time in minutes
Measured: 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Oct 2026
- Study start19 Oct 2026 (estimated)
- Primary completion1 Apr 2028 (estimated)
- Study completion1 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial Fibrillation (AF)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- East Sussex Healthcare NHS Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rahul Mukherjee, East Sussex Healthcare NHS Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07900685
- Sponsor's protocol ID
- CONSCIOUS-PFA
- Acronym
- CONSCIOUS-PFA
- Status last verified
- Oct 2026
- First submitted
- 16 Oct 2026
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Comparison of Pulsed Field Ablation (PFA) vs Cryoablation for Atrial Fibrillation Under Deep Sedation
- ClinicalTrials.gov ID
- NCT07900685
- Acronym / sponsor ID
- CONSCIOUS-PFA / CONSCIOUS-PFA
- Conditions
- Atrial Fibrillation (AF)
- Keywords
- ablation, atrial fibrillation, pulsed field ablation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- East Sussex Healthcare NHS TrustUniversity, hospital or other
- Study start
- 19 Oct 2026 (estimated)
- Primary completion
- 1 Apr 2028 (estimated)
- Study completion
- 1 Oct 2028 (estimated)
- First posted
- 28 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Pulsed Field Ablation (PFA) has created a 'paradigm shift' within cardiac electrophysiology and the initial experience demonstrates that PFA is safe, rapid and effective compared to both radiofrequency ablation and cryoablation in atrial fibrillation (AF). Presently, AF ablation procedures in the UK using PFA are routinely performed using general anaesthetic (GA) support requiring an anaesthetist and ODP being present in all procedures. This need significantly limits the ability to use PFA technology to perform AF ablations, particularly in centres that have limited availability of GA provision.
The need for GA also leads to extended patient recovery time post procedure which impacts patient throughput and has the potential to reduce hospital bed availability. The need for GA and the potential to limit patient throughput has negative implications for all hospitals in terms of cost. PFA procedures performed elsewhere in Europe use deep sedation with IV propofol led by the ablating physician, but this is not permitted in the UK and still requires the presence of an anaesthetist.
The investigators will aim to evaluate if AF ablation using PFA is feasible during spontaneous respiration without the use of propofol. The investigators will conduct a non-randomized study comparing AF ablation using PFA vs cryoballoon under deep sedation - aiming to demonstrate that >75% of patients can complete the PFA protocol under deep sedation without conversion to cryoballoon (due to patient intolerance). The principal aim of the study is therefore not to demonstrate superiority or comparative efficacy of one ablation modality over another but rather the ability and feasibility to deliver pulsed field ablation under deep sedation. The use of cryoablation serves as a benchmark comparator to contextualise procedural and sedation-related observations.
Detailed description
60 patients undergoing a clinically-indicated AF ablation procedure will be allocated in a 2:1 ratio to either receive PFA or cryoballoon. All procedures will be completed using deep sedation using intravenous fentanyl or remifentanil infusion and midazolam. Additionally, a bolus of intravenous lidocaine will be given to suppress the cough reflex during PFA applications. If a participant is unable to tolerate the procedure using PFA, the procedure will be converted to cryoballoon during the same sitting and completed as per standard clinical protocol. It is anticipated that general anaesthesia will not be required for any participants in the study.
If the study proves successful, this will provide a clear deep sedation protocol for use with PFA during pulmonary vein isolation with a view to reducing the need for GA cover and improve lab efficiency which has significant financial implications for NHS healthcare providers.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Pulsed field ablation group under deep sedation | Experimental | Device: Catheter ablation, Drug: Deep sedation with midazolam and fentanyl or midazolam and remifentanil |
| Cryoablation group under sedation | Active comparator | Device: Catheter ablation, Drug: Sedation with midazolam and fentanyl |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients with paroxysmal or persistent AF requiring a clinically-indicated AF ablation
- Age >18 years old
- Able to give informed consent
Key exclusion criteria (5 listed)
- Patients with a BMI >35
- Any patient with a history of airway issues/Obstructive sleep apnoea/ obesity hypoventilation syndrome
- Significant acid reflux or presence of a large hiatus hernia
- Lack of capacity to give informed consent
- Unable to lie flat for a minimum of 45 mins
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Catheter ablationCatheter ablation for AF | Device | Cryoablation group under sedation, Pulsed field ablation group under deep sedation |
| Deep sedation with midazolam and fentanyl or midazolam and remifentanilDuring ablation, sedation will be given with either midazolam and fentanyl or midazolam and remifentanil | Drug | Pulsed field ablation group under deep sedation |
| Sedation with midazolam and fentanylSedation using lower doses of midazolam and fentanyl | Drug | Cryoablation group under sedation |
Primary outcome
Percentage of patients able to complete protocol with pulsed field ablation without conversion to cryoablaton
Time frame: 18 months
Target is 75% of patients
3 secondary outcomes
Numeric Rating scale for pain - Pain severity index (PSI)
Time frame: 18 months
- Patient Experience Questionnaire for post-procedural pain, discomfort - Visual Analogue Scale (VAS) - Atrial Fibrillation Specific Patient Reported Outcome Measures Questionnaire (AF-PROMs) questionnaire
Time frame: 18 months
- Lab occupancy time/ skin-to-skin time
Time frame: 18 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Catheter ablation, Deep sedation with midazolam and fentanyl or midazolam and remifentanil and Sedation with midazolam and fentanyl in people with Atrial Fibrillation (AF), run by East Sussex Healthcare NHS Trust at 1 site in United Kingdom.
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 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: looking for participants now, as of the sponsor's last update on 28 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 1 site in United Kingdom. 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 Jo-Anne Taylor (0300 13 14 500 ext. x771439, esh-tr.researchanddevelopment@nhs.net), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of patients able to complete protocol with pulsed field ablation without conversion to cryoablaton (time frame: 18 months). 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 28 Oct 2026.