A decade of complex fractionated electrograms catheter-based ablation for atrial fibrillation: Literature analysis, meta-analysis and systematic review

Abstract

Background: It has been a decade since the complex fractionated atrial electrograms (CFAEs) were first established following the publication of Nademanee's standards. However, the status and focus of CFAE research are unclear, as is the efficacy of additional CFAE ablation in atrial fibrillation (AF). This literature review and metaanalysis were designed to determine the status of CFAE research and the efficacy and complications of CFAE ablation alone, pulmonary vein isolation (PVI) alone and PVI plus CFAE ablation in AF. Methods: With the assistance from reference librarians and investigators trained in systematic review, we conducted a literature search of MEDLINE (via PubMed), Embase, the Cochrane Library, ScienceDirect, Wiley Blackwell and Web of Knowledge, using "complex fractionated atrial electrograms" for MeSH and keyword search. Results: The literature on CFAEs increased from 2007, mainly focusing on mapping studies, with mechanism studies increasing significantly from 2012. Fifteen trials with 1525 patients were qualified for our meta-analysis. Success rates were as follows. Overall (P b 0.001): CFAE ablation alone, 23.5-26.2%; PVI, 64.7%; PVI plus CFAE ablation, 67.0%. Single ablation: PVI, 60.4%; PVI plus CFAEs, 68.8% (OR 1.53, 95% CI 1.07-2.20, P = 0.02). Reablation: PVI, 69.0%; PVI plus CFAEs, 77.2% (OR 1.54, 95% CI 1.06-2.24, P = 0.02). Paroxysmal AF: PVI, 76.7%; PVI plus CFAEs, 79.1% (OR 1.20, 95% CI 0.79-1.81, P = 0.39). Persistent or permanent AF: PVI, 47.9%; PVI plus CFAEs, 58.7% (OR = 1.59, 95% CI 1.13-2.24, P = 0.008). Complication rates: PVI, 2.6%; PVI plus CFAEs, 3.4% (OR 1.22, 95% CI 0.58-2.57, P = 0.61). Conclusions: In the literature, CFAE mapping studies preceded mechanism studies. CFAE ablation alone is insufficient for the treatment of AF. Additional CFAE ablation after adequate PVI or PVI plus linear ablation improves the outcome of single ablation and re-ablation without increasing complications, especially in persistent or permanent AF. There are insufficient data to support a similar improvement in paroxysmal AF or inducible AF after PVI for paroxysmal AF.

Information Theory and Atrial Fibrillation (AF): A Review

“…A number of sources are said to be responsible for fractionation, with the local collision of multiple wavelets, local re-entry and zones of slow conduction said to result in EGM fractionation during AF (de Bakker and Wittkampf, 2010 ; Waks and Josephson, 2014 ). Consequently, it is thought that there is some relationship between CFAE and the maintenance of AF (Waks and Josephson, 2014 ), thus CFAE mapping and CFAE guided ablation have previously been explored (Nademanee et al, 2004 ; Nademanee and Oketani, 2009 ; Berenfeld and Jalife, 2011 ; Hayward et al, 2011 ; Li et al, 2011 ; Chen et al, 2014 ). Though both CFAE and entropy aim to capture the qualitative property of signal fractionation to some degree, entropy is differentiated from CFAE by having a quantitative definition rooted in signal processing and mathematics, and does not use empirically derived definitions.…”

New concepts in the therapy of atrial fibrillation

“…Recent meta-analyses [3,36] report that 77% of the ablation-treated patients are asymptomatic at a 1-year follow-up, in comparison to 52% of medically treated patients. It should be noted that up to a third of patients requires a 2 nd ablation (redo-ablation) to achieve a long-lasting symptom-free life [3,4,23,25,38]. We still lack enough information to personalize ablation in each individual, which could results in more efficacious and less extensive ablation in some patients [39].…”

Complexity of Atrial Fibrillation Electrograms Through Nonlinear Signal Analysis: In Silico Approach

“…CFAE definition does not distinguish between different morphologies; consequently, fractionated EGM according with CFAE definition are not necessarily related to arrhythmogenic substrates. Moreover, several studies have shown conflicting results with Nademanee [56,59]. This may lead the electrophysiologist to confuse the fractionated EGM that are functional in nature [60] with fractionated EGM corresponding to arrhythmogenic sources, leading to incorrect target sites for ablation.…”