The Basel CardioInsightTM - 3D Mapping Study

Study Overview
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Brief Summary
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This study is to describe the exact location of NOAF-maintaining foci and rotors after cardiac surgery identified by mapping using the non-invasive phase mapping with CardioInsightTM - 3D Mapping technology (CardioInsightTM, Medtronic Switzerland, Tolochenaz, Switzerland) and a low-dose computed tomography scan of the chest.

Detailed Description
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Atrial fibrillation (AF) is the most commonly oberserved postoperative complication after cardiac surgery. New-onset atrial fibrillation (NOAF) leads to prolonged intensive care unit (ICU) and hospital length of stay, increased early mortality and stroke along with higher treatment costs. The exact location of structures triggering or maintaining NOAF is unknown. Identifying the exact location of NOAF- maintaining foci and rotors could allow development of preventive treatment strategies like preoperative ablation or perioperative ablation of high-risk foci. Non-invasive phase mapping with CardioInsightTM (CIT) - 3D Mapping technology (CardioInsightTM, Medtronic Switzerland, Tolochenaz, Switzerland) allows non-invasive description of AF foci and rotors with a 252-electrode vest applied to the patient's torso due to detailed mapping of NOAF-maintaining structures without invasive electrophysiological examination. This study is to describe the exact location of NOAF-maintaining foci and rotors after cardiac surgery identified by mapping using the non-invasive phase mapping with CardioInsightTM - 3D Mapping technology (CardioInsightTM, Medtronic Switzerland, Tolochenaz, Switzerland) and a low-dose computed tomography scan of the chest.

Official Title
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Non-invasive Evaluation of New-onset Atrial Fibrillation After Cardiac Surgery The Basel CardioInsightTM - 3D Mapping (BigMap) Study

Conditions
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New-onset Atrial Fibrillation (NOAF)

Intervention / Treatment
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* Diagnostic Test: Mapping
* Diagnostic Test: Computed tomography scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cardiac surgery Signed informed consent by patient or next of kin Mapping inclusion criteria NOAF within the first seven postoperative days (168 hours) after cardiac surgery developing on the cardiac surgery ward, intermediate care unit or the intensive care unit of the University Hospital Basel. ICU admission will be set as starting point for observation time. General Exclusion Criteria: Preoperative conditions: History of previous left atrial ablation History of cardioembolic stroke History of amiodarone treatment within three months Any documented history of atrial fibrillation/atrial flutter before surgery Left ventricular ejection fraction <40% Patient included into other study with radiation exposure Perioperative conditions Perioperative mechanical circulatory support (e.g., intraaortic balloon pump; extracorporeal membrane oxygenation; left ventricular assist device (e.g. Impella, Abiomed Inc., Aachen, Germany) Mapping exclusion criteria Heart rate ≥ 50 bpm AND contraindication to adenosine. Contraindications to adenosine: Allergy/intolerance to adenosine History of chronic obstructive pulmonary disease (COPD Gold IV)(28) History of asthma History of Long-QT syndrome Hemodynamically unstable patients (margin of discretion of the attending physician)

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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Mapping|CardioInsightTM Cardiac Mapping System is a non-invasive single beat cardiac mapping system that provides three-dimensional electroanatomic maps of the heart. The CIT vest is attached to the patient's torso for non-invasive mapping. To ensure correct and rapid mapping of the NOAF by the CIT device, it is essential to briefly slow down the patient's heart rate below 50bpm for a few seconds. Therefore 6mg adenosine as a rapid i.v. bolus will be administered. The adenosine application will slow down the patient's heart rate and allow for correct mapping by the CIT device. Medical therapy of atrial fibrillation is started immediately according to local protocol. Since non-invasive mapping is performed within a few minutes, the therapy of atrial fibrillation will not be critically delayed. Consecutively, a low-dose thoracic computed tomography (CT) scan (neck to upper abdomen) will be performed independent from the patient's rhythm.|
|Diagnostic Test: Computed tomography scan|The CT scans will follow a standardised protocol as predefined by the manufacturer of the CIT vest, Medtronic (Dublin, Ireland). After the sensor array has been placed on the patient, the patient is ready to undergo a CT scan to register each electrode's locations with respect to the body surface. All CT scans cover a body region from neck to the upper abdomen, have no cardiac gating performed or any contrast agent given. The CT scans are acquired on 3 CT scanners manufactured by Siemens Corporation (Berlin, Germany) with a fixed tube voltage of 80 kVp and 250 effective mAs (=mAs/pitch). The reconstruction parameters are of 3 mm slice thickness and of 1.5 mm increment (slice overlap) The estimated effective dose (ED) is 3.2 mSv per patient.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| localisation of foci and rotors maintaining NOAF after cardiac surgery identified by mapping | localisation of foci and rotors maintaining NOAF after cardiac surgery identified by mapping system as three-dimensional electroanatomic map of the heart. | one time assessment at baseline (up to 5 minutes) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pulmonary vein isolation, atrial fibrillation (AF), cardiac surgery, reentrant circuits, rotors, left atrial foci, CardioInsightTM (CIT) - 3D Mapping technology, NOAF-maintaining foci