Patterns of pulmonary vein activity that may help identify patients who need further ablation beyond pulmonary vein isolation in persistent AF

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation Background Pulmonary vein isolation (PVI) is the cornerstone interventional treatment for AF. While this strategy is effective in paroxysmal AF, the success rate of this approach is more limited in persistent AF (PsAF). In these pts, the main challenge is to discriminate those who will respond to PVI only, from those who may require an extended ablation strategy. Purpose We aimed to evaluate whether the analysis of the electrical activity recorded within the PV may provide the key to discriminate passive PV from PV playing an active role. Methods Three-subgroups of consecutive pts who underwent first-time PVI for PsAF were considered based on the mechanism of AF: 1) definitely related to PV, based on procedural AF termination during PVI (the "PV-term" group) 2) likely PV-dependent, based on the absence of AF recurrence > 18 months off-antiarrhythmic drugs after PVI only (the "PV-dep" group) 3) definitely/likely independent of the PV, based on PsAF recurrence despite isolated PV or at least one redo consisting of PV reisolation only, respectively ("PV-indep"). PV activity during AF was assessed using Lasso recordings before ablation. An automatic detection algorithm was developed to extract atrial activations from intra-cardiac electrograms in order to perform further analyses. Epochs of 60-sec were used. Different methods based on the atrial cycle length variability were assessed to best characterize the potential markers of PV activity such as the occurrence of intermittent bursts of rapid activity. Each PV and the left atrial appendage (LAA) were evaluated. Results A total of 40 pts were included (mean age: 60.0 ± 9.9 years, mean PsAF duration: 4.4 ± 4.3 years) (PV-term group (n=10), PV-dep group (n=17), PV-indep group (n= 13)). The dynamics of PV activation intervals was assessed using the envelope of the PV intervals time series (Figure 1A shows representative examples of each group). Among all features evaluated, the best feature that could discriminate similarly both the PV-term and the PV-dep group from the PV-indep group, was the standard deviation of the inferior envelope relative to the median CL of the vein (p <0.001 and p = 0.005, respectively) (Figure 1B). Cut-off selected by ROC analysis provided a 100% sensitivity and 85% specificity to discriminate the PV-term from the PV-indep group (AUC 0.931) and a 88% sensitivity and 77% specificity to discriminate the PV-dep from the PV-indep group (AUC 0.805). We compared this feature with the Fastest PV run (mean CL of the fastest 10-beat run) as recently described (p = 0.04, AUC = 0.762 and p = 0.03, AUC = 0.738, respectively) (Figure 2). Conclusions The assessment of the CL variations recorded within the PV before PsAF ablation may provide the key to discriminate pts who may be cured by PVI only.