Specific Electrophenotypes in Atrial Fibrillation

Study Overview
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Brief Summary
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This study will investigate a common heart rhythm disturbance (arrhythmia), atrial fibrillation (AF), to improve understanding of how best to treat it in different patients. Direct current cardioversion (DCCV) is a procedure that can revert the heart to a normal rhythm, however almost all patients will only have a transient benefit, and their heart will return to the abnormal rhythm, AF. Ablation is an invasive procedure that creates scar tissue within the heart to reduce the arrhythmias, with a longer lasting effect than DCCV. It has been used with success in AF that occurs occasionally (paroxysmal) but is not as effective in AF that is more long-lasting, also known as persistent AF. Persistent AF is major cause of symptoms of breathlessness and palpitations and significantly increases the risk of stroke. Doctors are unable to accurately predict which patients will benefit most from an ablation, this can lead to as many as 50% of patients not benefitting from the procedure. The aim is to better predict which patients will benefit from an ablation. The study will include patients undergoing AF ablation or DCCV and perform additional tests including blood tests a heart MRI scan, a special type of heart tracing with up to 252 points and a short period of extra recordings from within the heart during the ablation procedure. Several techniques will be used to analyse this data, including machine learning, to develop a means predict which patients will benefit the most from the ablation procedure, without needing to use any recordings from within the heart.

Official Title
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IdeNtification of SPecific EleCTrophenotypes in Atrial Fibrillation

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Other: Biomarkers, electrocardiographic imaging, intracardiac electrograms, cardiac magnetic resonance imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Suitable candidate for catheter mapping/ablation for arrhythmias or direct current cardioversion for atrial fibrillation Signed Informed Consent Exclusion Criteria: Severe cerebrovascular disease Moderate to severe renal impairment (eGFR < 30) Active gastrointestinal bleeding Active infection or fever Short life expectancy Significant anaemia Severe uncontrolled systemic hypertension Severe electrolyte imbalance Congestive heart failure - NYHA Class IV Recent myocardial infarction Bleeding or clotting disorders Uncontrolled diabetes Inability to receive IV or oral Anticoagulants Unable to give informed consent Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Biomarkers, electrocardiographic imaging, intracardiac electrograms, cardiac magnetic resonance imaging|ECGi is a non-invasive body surface mapping technique that collects electrocardiographic data using 252 leads, and combines it with subject specific anatomic data acquired from cross sectional imaging to recreate epicardial electrograms.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from atrial fibrillation | Percentage of patients who do not have a recurrence of atrial fibrillation | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atrial fibrillation burden | Mean number of episodes of atrial fibrillation | 1 year | 
| Atrial fibrillation related symptoms and quality of life | Mean Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) score | 1 year | 
| Health related quality of life | Mean Short Form 36 (SF-36) score | 1 year |