Comparison of the Performance of Implantable Cardiac Monitors and Cardiac Implantable Electronic Devices in Detecting Atrial Fibrillation

Study Overview
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Brief Summary
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Atrial fibrillation (AF) is the most common abnormal heart rhythm disturbance, affecting 1-2 million people in the UK. The irregular heartbeat caused by AF can make the heart pump blood less efficiently. As a result, AF significantly increases the risk of having a stroke, heart failure and dementia. However, a significantly proportion of people have no symptoms, and they may be only found to be in AF after having a stroke. Therefore, diagnosis largely relies on accurate electrocardiogram (ECG) monitoring. AF episodes can be unpredictable and easily missed unless continuous ECG monitoring is undertaken. Pacemakers can continuously record the heart's electrical activity and detect AF with a high degree of confidence. However, they are invasive and rely on electrical wires implanted inside the heart, and hence less suited to be used as primary monitoring devices. To overcome these difficulties, implantable cardiac monitors (ICM) have been designed to be placed under the skin. The new generation of ICMs can now be injected under the skin. Moreover, they connect with the patient's smartphone and transmit recordings. Despite these significant improvements, their ability to reliably capture AF has never been tested against pacemakers. The aim of this project is to study the performance of the two commonly used ICMs in detecting AF episodes and explore how the new connectivity can empower patients and improve patient care. The investigators plan to inject an ICM in 30 patients with AF and pre-existing pacemaker. After a period of 6 months, the investigators will compare how many episodes were detected in each device. With the information collected the investigators will try to understand the pitfalls in the current technology and develop strategies to improve it. Accurate, minimally invasive long-term ECG monitor can have far reaching benefits for patients, both in routine clinical practice and research.

Official Title
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Comparison of the Performance of Implantable Cardiac Monitors and Cardiac Implantable Electronic Devices in Detecting Atrial Fibrillation

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Device: Confirm Rx (Implantable Cardiac Monitor)
* Device: Reveal LINQ (Implantable Cardiac Monitor)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant is willing and able to give informed consent for participation in the trial. Male or Female. Aged 18 years or above. History of paroxysmal and persistent AF. Dual-chamber pacemaker, Implantable cardioverter defibrillator (ICD) or cardiac resynchronisation therapy (CRT) device with a functioning atrial lead, able to record electrograms and remote monitoring. Exclusion Criteria: Diagnosis of permanent AF. Contra-indications for implantable cardiac monitor. Unable to comply with the follow-up schedule.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Confirm Rx<br>Patient with cardiac implantable electronic devices with an atrial lead will have Confirm Rx Implantable Cardiac Monitor injected in the anterior chest wall. | Device: Confirm Rx (Implantable Cardiac Monitor)<br>* Confirm Rx implanted in patients with atrial fibrillation detected on their cardiac implantable electronic device (CIED)<br>|
| Other: LINQ<br>Patient with cardiac implantable electronic devices with an atrial lead will have LINQ Implantable Cardiac Monitor injected in the anterior chest wall. | Device: Reveal LINQ (Implantable Cardiac Monitor)<br>* Reveal LINQ implanted in patients with atrial fibrillation detected on their cardiac implantable electronic device (CIED)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the performance of the Confirm Rx™ ICM and Reveal LINQ™ ICM in detecting clinically significant AF episodes (episodes longer than 6 minutes) to CIED (gold standard). | Confirm Rx and Reveal LINQ™ ICM sensitivity, specificity, positive predictive value and negative predictive value will be calculated for AF episodes longer than 6 minutes. | During follow-up (6 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the changes in R-wave amplitude following implantation in both ICMs. | Compare the percentage of changes in R-wave amplitude between both ICMs. | During follow-up (6 months) | 
| To compare the transmission success rate of both devices. | The percentage of successful transmission in both ICMs will be calculated. | During follow-up (6 months) | 
| To compare the number of patient- activated recordings that contains symptoms. attributed to those episodes. | The percentage of activated recordings with symptoms will be calculated. | During follow-up (6 months) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Confirm Rx, Reveal LINQ