Left Atrium Reservoir Function Modulation in Patients With Atrial Fibrillation: Digoxin Versus Beta Blocker

Study Overview
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Brief Summary
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ß blocker and digoxin effect on left atrium reservoir function are unknown. This is a randomized open label study to compare the effect of theses two molecules on left atrium function

Detailed Description
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Atrial fibrillation (AF) is responsible of significant morbidity and mortality. Management of signs and symptoms of heart failure generated by AF is at the center of the latest European recommendations . Mechanisms by which these symptoms are generated are very poorly understood. Heart rate control is one of the recommended strategies but remains poorly codified and generally follows the preferences and experiences of each local center. The European guidelines propose at least 4 molecules for heart rate control without emitting preferences for one molecule over the other due to the lack of robust randomized studies. Recently, a study comparing digoxin vs ß-blockers showed the superiority of digoxin in decreasing symptoms despite a comparable action on heart rate. On the other hand, the reservoir function of the left atrium (LA) has taken a central role in assessing signs of left heart failure and monitoring filling pressures . Other studies have demonstrated the association of left atrium reservoir strain with these symptoms . It is commonly accepted that ß blockers decrease AF-related symptoms by a negative chronotropic effect thanks to their blocking action on the sympathetic system. While the action of digoxin on symptoms goes through a positive inotropic effect thanks to the increase in intracellular calcium . However, the impact of these two molecules on the function of the left atrium has never been investigated. Our diagnostic hypothesis is that in addition to their action on heart rate, the improvement of symptoms noted by using b blockers and digoxin during the treatment of AF would go through an improvement LA reservoir function . The superiority of digoxin in the reduction of symptoms compared to ß blockers would be due to a greater improvement in reservoir function and this thanks to the increase in myocardial intracellular calcium.

Official Title
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Left Atrium Reservoir Function Modulation in Patients With Atrial Fibrillation: A Randomized Digoxin Versus Beta Blocker Study

Conditions
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Atrial Fibrillation, Left Atrial Rhythm

Intervention / Treatment
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* Drug: Digoxin 0.25 mg
* Drug: Bisoprolol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Any patient with atrial fibrillation naïve to ß-blocker and digoxin or patients followed for Atrial fibrillation and discontinued all treatment for more than a week. Frequency Control Strategy Decided Age over 18 years Stable hemodynamic state No contraindication to digoxin or ß-blocker Exclusion Criteria: Required rhythm control strategy Contraindication to one of the two Heart rate <60 BPM Clearance rénale <30 ml/mn Pregnant or breastfeeding woman Persistence of a resting heart rate > 110 Severe comorbidity with decreased life expectancy (advanced neoplasia, large stroke...)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Digoxin group<br>Patients will receive digoxin 0.25 mg once daily for a duration of 4 weeks | Drug: Digoxin 0.25 mg<br>* Patients will have the dose of one tablet of 0.25mg per day<br>|
| Experimental: beta blocker group<br>Patients will receive bisoprolol 2.5 mg or 5 m twice a day for a duration of 4 weeks. The choice of dose will depend on blood pressure (BP): If systolic BP ≥ 150 mmHG, the patient will have bisoprolol 5 mg x 2 per day, If systolic BP < 150 mmHG, the patient will have bisoprolol 2.5 mg x 2 per day | Drug: Bisoprolol<br>* Patients will have the dose of bisoprolol 2.5 mg or 5 mg twice a day based on the arterial pressure at randomization<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Left atrium reservoir strain before and after treatment | Measurements of Left atrium reservoir strain will be performed at randomization and after 4 weeks on 4 chambers and 2 chamber views according to the most recent recommendations. The acquisition of strain-2D curves will be made by taking as a reference the beginning of the QRS complex. The peak of the curve corresponds to the value of the reservoir strain of the left atrium | 4 weeks |