Conference Coverage
DECAAF points way to improved AF ablation
Major Finding: Patients undergoing a first ablation procedure for atrial fibrillation had an 86% long-term rate of maintenance of sinus rhythm if...
For patients scheduled to undergo AF catheter ablation, estimating the extent of atrial fibrosis using delayed enhancement MRI can help distinguish those likely to respond from patients likely to have recurrent arrhythmia, according to a report published online Feb. 4 in JAMA.
In the prospective, observational DECAAF (Delayed-Enhancement MRI Determinant of Successful Radiofrequency Ablation of Atrial Fibrillation) study, 260 such patients (mean age, 59 years) underwent quantification of left atrial fibrosis via delayed enhancement MRI with gadolinium at 15 medical centers in six countries, before undergoing AF ablation. These centers had varying levels of experience with cardiac imaging and used different ablation procedures, said Dr. Nassir F. Marrouche, director of the comprehensive arrhythmia and research management center, University of Utah, Salt Lake City, and his associates.
Dr. Nassir F. Marrouche
Four categories of fibrosis were used: involvement of less than 10% of the atrial wall (stage 1, 49 patients), 10%-19% of the atrial wall (stage 2, 107 patients), 20%-29% of the atrial wall (stage 3, 80 patients), and 30% or more of the atrial wall (stage 4, 24 patients). The estimated percentage of atrial fibrosis strongly correlated with arrhythmia recurrence at 1 year, even after the data were adjusted to account for variables such as patient age and sex; the presence of hypertension, heart failure, mitral valve disease, or diabetes; and the type of AF (paroxysmal vs persistent).
The hazard ratio for recurrent arrhythmia was 1.06 for every 1% increase in the extent of atrial fibrosis (JAMA 2014 Feb. 4 [doi:10.1001/jama.2014.3]).
This is the first multicenter study to demonstrate the feasibility and potential clinical value of quantifying the degree of AF fibrosis using delayed enhancement MRI before performing ablation, offering a noninvasive, effective method for determining which patients are likely to benefit and which should avoid the procedure, Dr. Marrouche and his associates said.
The JAMA report expands on results presented at the annual meeting of the Heart Rhythm Society last year.
The study was funded by the Comprehensive Arrhythmia and Research Management Center at the University of Utah and the George S. and Dolores Dore Eccles Foundation. Dr. Marrouche reported owning stock and being named in two patents licensed to Marrek; his associates reported numerous ties to industry sources.