Pulmonary Vein Antrum Isolation vs. AV Node Ablation With Biventricular Pacing for Treatment of Atrial Fibrillation in Patients With Congestive Heart Failure - PABA CHF

Description:

The goal of the trial was to evaluate the effect of pulmonary vein isolation (PVI) compared with atrioventricular (AV) node ablation with biventricular pacing among patients with atrial fibrillation and congestive heart failure (CHF).

Study Design

Patients Enrolled: 77
Mean Follow Up: 6 months
Mean Patient Age: Mean age 60 years
Female: 9

Patient Populations:

EF ≤40%, symptomatic refractory ischemia, ability to complete 6-minute walk test, and adequate rate control

Exclusions:

Reversible cause of atrial fibrillation or heart failure

Primary Endpoints:

Six-minute walk test, Minnesota Living With Heart Failure Questionnaire, and EF on echocardiography

Secondary Endpoints:

Freedom from atrial fibrillation and left atrial size

Drug/Procedures Used:

Patients were randomized to PVI (n = 39) or AV node ablation with biventricular pacing (n = 38). At baseline and 6 months, patients underwent 6-minute walk test, echocardiography, and Minnesota Living With Heart Failure Questionnaire. Repeat PVI procedures could be performed as needed after 2 months. Patients were to receive optimal medical therapy (beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers).

Principal Findings:

Type of atrial fibrillation at baseline was paroxysmal in 54% of patients and persistent/permanent in 46% of patients. Mean duration of atrial fibrillation was 4 years. Coronary artery disease was present in 73% of patients. Mean ejection fraction (EF) was 28% and left atrial size was 4.8 cm.

Freedom from atrial fibrillation without antiarrhythmic medication and more than one procedure by 6 months was present in 72% of the PVI group and 0% of the AV node ablation group (p < 0.05). Use of antiarrhythmic therapy was similar between groups (p = 0.12). EF was higher in the PVI group than in the AV node ablation group at 3 months (p = 0.01) and 6 months (35% vs. 28%, p = 0.0004). In the PVI group, 74% of patients had improved EF compared with 24% of the AV node ablation group (p < 0.001).

The 6-minute walk test was improved in 95% of patients in the PVI group compared with 58% of the AV node ablation group (p < 0.001). Walk distance was 338 in the PVI group vs. 297 in the AV node ablation group (p = 0.0001). Quality-of-life score was also better in the PVI group (60 vs. 80, p < 0.001). Results were consistent in those with paroxysmal and nonparoxysmal atrial fibrillation at baseline. There was one major complication in each group.

Interpretation:

Among patients with atrial fibrillation and CHF, PVI was associated with improvements in EF, 6-minute walk test, and quality-of-life scores at 6 months compared with AV node ablation with biventricular pacing.

Results of the present study, which favor rhythm control over rate control, differ from that of the much larger AFFIRM trial, which favored rate control over rhythm control. However, there are several differences between the studies, including the focus on patients with CHF in addition to atrial fibrillation in the present study and the mode of rate and rhythm control in the two trials. It is not known how many procedures were required in the PVI group.

Additionally, it should be noted that the present study was very small (only 77 patients) and was conducted at expert experienced centers in these procedures. Larger trials involving many hospitals would be needed before widespread use of the therapy could be widely adopted.

References:

Khan MN, Jaïs P, Cummings J, et al. Pulmonary-vein isolation for atrial fibrillation in patients with heart failure. N Engl J Med. 2008 Oct 23;359(17):1778-85.

Presented by Dr. Andrea Natale at the American Heart Association Annual Scientific Sessions, Chicago, IL, November 2006.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Echocardiography/Ultrasound

Keywords: Coronary Artery Disease, Cardiac Pacing, Artificial, Pulmonary Veins, Heart Failure, Questionnaires, Catheter Ablation, Cardiac Resynchronization Therapy, Echocardiography, Atrioventricular Node


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