The Effect of Beta-blocker on Chronotropic Response and Cardiorespiratory Fitness in Patients With Atrial Fibrillation

National Taiwan University

Status: Enrolling

Conditions: Atrial Fibrillation

Treatments: Drug: Reduced dosage of beta-blocker

Study type: Interventional

Funder types: Other

Identifiers

NCT05332457

202201028MINB

Details and patient eligibility

About

This is a prospective study to evaluate changes in exercise capacity and chronotropic response to exercise before and after beta-blocker dosage reduction in patients with atrial fibrillation (AF).

Full description

Rate control therapy is the first-line treatment for atrial fibrillation (AF). Resting heart rate(HR) is the treatment target of rate control therapy in current clinical practice; However, the optimal value for resting heart rate in AF remained unclear. Beta-blocker(BB) is widely used as rate-control agent. It is concerned that excessive use of BB might lead to a negative effect on exercise capacity in patients with AF. The aim of this study is to explore the effect of Beta-blocker on hemodynamic parameters and peak oxygen uptake during cardiopulmonary exercise test (CPET).

Enrollment: 40 estimated patients

Sex: All

Ages: 20+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. > 20 years of age.
2. Clinically stable patients with persistent atrial fibrillation using beta-blocker as rate-control agent without dosage adjustment for at least 3 months.
3. Resting heart rate < 80 bpm.
4. Left ventricular ejection fraction > 50%.

Exclusion criteria

1. Beta-blocker usage due to indications other than rate control for atrial fibrillation.
2. Inability to perform a cardiopulmonary exercise testing.
3. Presence of contraindications for cardiopulmonary exercise testing according to the American College of Sports Medicine's Guidelines for Exercise Testing and Prescription.
4. Patients with implantable cardioverter defibrillator or pacemaker.
5. Pregnancy.
6. Inability to provide informed consent.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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40 participants in 2 patient groups

Arm A

Active Comparator group

Description:

Phase I : Participants will undergo first CPET (Day 0) at trough concentration of BB. After 7-day regular usage of BB, the second CPET(Day 7) will be performed at peak concentration of BB. Participants will enter the second phase if the results of CPET fulfill the pre-determined conditions as follows: (1) Chronotropic index \< 0.8 at peak level of BB, (2) Resting HR \< 110 bpm at trough level of BB, (3) Absent of unstable arrhythmia or unstable hemodynamics during CPET at trough level. Phase II: BB dosage will be reduced. Daily blood pressure, heart rate and adverse event will be recorded. If participants remained clinically stable, the third CPET(Day 21) will be performed 14 days after the reduction of dosage. If participants' resting heart rate exceed 110 bpm, the dosage will be adjusted to the original level.

Treatment:

Drug: Reduced dosage of beta-blocker

Arm B

Active Comparator group

Description:

Phase I : Participants will undergo first CPET(Day 0) at peak concentration of BB. After 7-day regular usage of BB, the second CPET(Day 7) will be performed at trough concentration of BB. Participants will enter the second phase if the results of CPET fulfill the pre-determined conditions as follows: (1) Chronotropic index \< 0.8 at peak level of BB, (2) Resting HR \< 110 bpm at trough level of BB, (3) Absent of unstable arrhythmia or unstable hemodynamics during CPET at trough level. Phase II: BB dosage will be reduced. Daily blood pressure, heart rate and adverse event will be recorded. If participants remained clinically stable, the third CPET(Day 21) will be performed 14 days after the reduction of dosage. If participants' resting heart rate exceed 110 bpm, the dosage will be adjusted to the original level.

Treatment:

Drug: Reduced dosage of beta-blocker