Kent Nilsson, MD; Steven Castellano, PhD; Melissa H. Kong, MD; Pawel Derejko, MD; Tamas Szili-Torok, MD, PhD; Sandeep Goyal, MD; Mohit Turagam, MD; Atul Verma, MD
ABSTRACT
Background
Electrographic Flow (EGF) identified extra-pulmonary vein sources of AF have been shown in the multicenter, randomized controlled FLOW-AF trial to significantly increase likelihood of AF recurrence within 1 year post-ablation if left unablated. Electrographic Flow Consistency (EGFC) measures the consistency of observed wavefront patterns over time providing an assessment of atrial substrate. The combination of both pathophysiologic mechanisms may provide prognostic information regarding AF recurrence post-ablation.
Objective
Analyze predictive power of EGF mapping for post-ablation outcomes.
Methods
Persistent and longstanding persistent AF (PeAF) patients from FLOW-AF trial received PVI-only. Post-PVI, pPanoramic EGF mapping performed post- PVIusing in 2-3 standardized basket positions per atrium was performed to identify AF sources and measure mean EGFC. Logistic regression models employed to predict recurrence at 1-year. Separate cohort of PeAF patients from the AF FLOW post-market registry was then used to test this model.
Results
A total of 56 FLOW-AF patientswith mean age 65±9yrs, 32% female, and mean left atrial size 4.5±0.6cm had 54%AF recurrence within 1 year. Among patients with AF recurrence after PVI alone,58% had clinically relevant sources with activity ≥26.5% v. 30% of patientswith FFAF (p=0.037). Similarly, patients with AF recurrence had lower EGFC(0.52±0.09) than those who were AF free (0.59±0.11), p=0.012. Patients withboth unablated extra-PV sources + low EGFC<0.60 had a 77% recurrence rate. Therewere 13 patients in the post-market AF-FLOW Registry, who had PVI-onlyprocedures. These patients had mean age60±12yrs, 23% female, and mean LA size 4.7±0.8cm. Using source presence and EGFC alonecorrectly predicted patient outcome with 77% accuracy.
Conclusions
EGF mapping provides insights into underlying disease pathophysiology such as extra-PV triggers and substrate mechanisms that can and may be used to predict likelihood of recurrence in patients undergoing ablation procedures.
Figure
Source presence v. EGFC for patients in (A) FLOW-AF and (B) AF-FLOW Registry. Blue indicates FFAF and red indicates recurrence with corresponding background color referring to prediction. Recurrence rates followed similar patterns by phenotype.
