Cryoballoon vs. open irrigated radiofrequency ablation for paroxysmal atrial fibrillation: long-term FreezeAF outcomes

Background: Effective treatment of paroxysmal atrial fibrillation (AF) is essential for reducing the risk of stroke and heart failure. Cryoballoon (CB) ablation has been developed as an alternative to the use of radiofrequency (RF) energy for electrical isolation of the pulmonary veins. Herein, we provide long-term data regarding the efficacy of CB ablation in comparison to RF. Methods: FreezeAF was a randomised non-inferiority study comparing CB ablation with RF ablation for the treatment of patients with drug-refractory paroxysmal AF. Procedural success for the long-term follow-up (30 months) was defined as freedom from AF with an absence of persistent complications. Results: Of the 315 patients that were randomised and received catheter ablation, 292 (92.7%) completed the 30-month follow-up (147 in the RF group and 145 in the CB group). The baseline characteristics of the RF and CB groups were similar. Single-procedure success was achieved by 40% of patients in the RF group and 42% of the CB group (p < 0.001 for non-inferiority). When including re-do procedures in the analysis, the multiple procedure success rate was 72% in the RF group and 76% in the CB group. Conclusion: The data provide long-term evidence that CB ablation is non-inferior to RF ablation, with high proportions of patients reporting freedom from AF 30 months after the index procedure. Trial registration: ClinicalTrials.gov Identifier: NCT00774566; first registered October 16, 2008; first patient included October 20, 2008

Characterization of complex fractionated atrial electrograms by Sample Entropy: An international multi-center study

Atrial fibrillation (AF) is the most commonly clinically-encountered arrhythmia. Catheter ablation of AF is mainly based on trigger elimination and modification of the AF substrate. Substrate mapping ablation of complex fractionated atrial electrograms (CFAEs) has emerged to be a promising technique. To improve substrate mapping based on CFAE analysis, automatic detection algorithms need to be developed in order to simplify and accelerate the ablation procedures. According to the latest studies, the level of fractionation has been shown to be promisingly well estimated from CFAE measured during radio frequency (RF) ablation of AF. The nature of CFAE is generally nonlinear and nonstationary, so the use of complexity measures is considered to be the appropriate technique for the analysis of AF records. This work proposes the use of sample entropy (SampEn), not only as a way to discern between non-fractionated and fractionated atrial electrograms (A-EGM), but also as a tool for characterizing the degree of A-EGM regularity, which is linked to changes in the AF substrate and to heart tissue damage. The use of SampEn combined with a blind parameter estimation optimization process enables the classification between CFAE and non-CFAE with statistical significance (p < 0:001), 0.89 area under the ROC, 86% specificity and 77% sensitivity over a mixed database of A-EGM combined from two independent CFAE signal databases, recorded during RF ablation of AF in two EU countries (542 signals in total). On the basis of the results obtained in this study, it can be suggested that the use of SampEn is suitable for real-time support during navigation of RF ablation of AF, as only 1.5 seconds of signal segments need to be analyzed.This work has been supported by the Spanish Ministry of Science and Innovation, Research Project TEC 2009-14222, by the Ministry of Education Youth and Sports of the Czech Republic, the Grant Agency of the Czech Technical University in Prague No. SGS13/203/OHK3/3T/13 and by the Czech Science 300 Foundation post-doctoral GACR research project GACR #P103/11/P106.Cirugeda Roldán, EM.; Novak, D.; Kremen, V.; Cuesta Frau, D.; Keller, M.; Luik, A.; Srutova, M. (2015). Characterization of complex fractionated atrial electrograms by Sample Entropy: An international multi-center study. Entropy. 17(11):7493-7509. https://doi.org/10.3390/e17117493S749375091711Haïssaguerre, M., Jaïs, P., Shah, D. C., Takahashi, A., Hocini, M., Quiniou, G., … Clémenty, J. (1998). 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Periprocedural anticoagulation during left atrial ablation: interrupted and uninterrupted vitamin K-antagonists or uninterrupted novel anticoagulants

Abstract Background There is a lack of data on anticoagulation requirements during ablation of atrial fibrillation (AF). This study compares different oral anticoagulation (OAC) strategies to evaluate risk of bleeding and thromboembolic complications. Methods We conducted a single-centre study in patients undergoing left atrial ablation of AF. Three groups were defined: 1) bridging: interrupted vitamin-K-antagonists (VKA), INR ≤2, and bridging with heparin; 2) VKA: uninterrupted VKA and INR of > 2; 3) DOAC: uninterrupted direct oral anticoagulants. Bleeding complications, thromboembolic events and peri-procedural heparin doses were assessed. Results In total, 780 patients were documented. At 48 h, major complications were more common in the bridging group compared to uninterrupted VKA and DOAC groups (OR: 3.42, 95% CI: 1.29–9.10 and OR: 3.01, 95% CI: 1.19–7.61), largely driven by differences in major pericardial effusion (OR: 4.86, 95% CI: 1.56–15.99 and OR: 4.466, 95% CI, 1.52–13.67) and major vascular events (OR: 2.92, 95% CI: 0.58–14.67 and OR: 9.72, 95% CI: 1.00–94.43). Uninterrupted VKAs and DOACs resulted in similar odds of major complications (overall OR: 1.14, 95% CI: 0.44–2.92), including cerebrovascular events (OR: 1.21, 95% CI: 0.27–5.45). However, whereas only TIAs were observed in DOAC and bridging groups, strokes also occurred in the VKA group. Rates of minor complications (pericardial effusion, vascular complications, gastrointestinal hemorrhage) and major/minor groin hemorrhage were similar across groups. Conclusion Our dataset illustrates that uninterrupted VKA and DOAC have a better risk-benefit profile than VKA bridging. Bridging was associated with a 4.5× increased risk of complications and should be avoided, if possible