The CONFIRM Trial1
The study authors hypothesized that human atrial fibrillation (AF or Afib) may be sustained by localized sources known as electrical rotors and focal impulses. Elimination of these sources called focal impulse and rotor modulation (FIRM) may improve patient outcomes.
Catheter ablation is one of various treatments for atrial fibrillation and its success is limited partly because of uncertainty in the mechanisms that sustain AF. The authors developed a computational approach to map the electrical wave fronts during AF. They then prospectively tested whether the targeting patient-specific mechanisms revealed by mapping would improve the results of AF ablation.
Ninety-two subjects were recruited during 107 consecutive ablation procedures for paroxysmal or persistent AF (72%). Cases were prospectively treated, in a 2-arm, 1:2 design, by ablation at sources (FIRM-guided therapy) followed by conventional ablation (n = 36), or conventional ablation alone (n = 71, FIRM-blinded therapy).
- The CONFIRM Trial demonstrated that AF may be sustained by rotors and focal impulses
- Conventional Ablation vs. FIRM-guided Ablation
- 66% Persistent in Conventional arm
- 81% Persistent in FIRM-guided arm
- Stable rotors were identified in 97.7% of patients
Localized electrical rotors and focal impulse sources are prevalent sustaining mechanisms for human AF. The findings offer a novel mechanistic framework of treatment for AF.
- Narayan SM, Krummen DE, Shivkumar K, Clopton P, Rappel W-J, and Miller JM. Treatment of Atrial Fibrillation by the Ablation of Localized Sources-CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) Trial. J Am Coll Cardiol 2012; 60(7):628-3