Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation - MAGIC-AF

Description:

The goal of the trial was to assess the efficacy of ibutilide in guiding catheter-based ablation for persistent atrial fibrillation (AF).

Contribution to the Literature: Ibutilide-guided complex fractionated atrial electrograms (CFAE) ablation is not efficacious in improving procedural characteristics or freedom from atrial arrhythmias at 12 months in patients with persistent AF.

Study Design

Patients with persistent AF and remaining in AF after pulmonary vein isolation (PVI) alone were randomized in a 1:1 fashion to either intravenous ibutilide 0.25 mg (n = 105) or placebo (n = 95).

  • Total number of enrollees: 200
  • Duration of follow-up: 1 year
  • Mean patient age: 60 years
  • Percentage female: 22%

Inclusion criteria:

  • Age ≥18 years
  • First-ever catheter ablation procedure for persistent AF

Exclusion criteria:

  • Reversible etiology of AF
  • Hypertrophic cardiomyopathy
  • Rheumatic heart disease
  • Congenital heart disease
  • Prior left-sided ablation procedure
  • Total number of enrollees: 200
  • Duration of follow-up: 1 year
  • Mean patient age: 60 years
  • Percentage female: 22%

Other salient features/characteristics:

  • CHA2DS2-VASc score: 1.5
  • Duration of AF: 9.5 months
  • Current medications: beta-blockers: 54%, antiarrhythmic drug (AAD) use: 37%

Principal Findings:

Primary efficacy endpoint, freedom from recurrent atrial arrhythmia >30 seconds in duration after a single ablation procedure without use of AADs after a 3-month post-ablation blanking period, for ibutilide vs. placebo: 56% vs. 49%, p = 0.38

Endpoint with or without AAD use: 62% vs. 51%, p = 0.14

Secondary outcomes:

  • Left atrial surface area with CFAE post-PVI: 23% vs. 19%, p = 0.2
  • AF termination with CFAE ablation: 71% vs. 56%, p = 0.03
  • Total CFAE ablation time: 30 vs. 25 minutes, p = 0.17

Interpretation:

The results of this trial indicate that ibutilide-guided CFAE ablation is not efficacious in improving procedural characteristics or freedom from atrial arrhythmias at 12 months in patients with persistent AF. However, ibutilide administration does reduce left atrial surface area with CFAE and also is associated with greater rates of AF termination during catheter ablation.

CFAE ablation is a method of left atrial substrate modification in patients with AF that is performed immediately following PVI. Other strategies to improve PVI outcomes in persistent and permanent AF are being evaluated given the high recurrence rates.

References:

Singh SM, d'Avila A, Kim YH, et al. The modified stepwise ablation guided by low-dose ibutilide in chronic atrial fibrillation trial (The MAGIC-AF Study). Eur Heart J 2016;Feb 4:[Epub ahead of print].


< Back to Listings