Abstract 18288: The Ablation Index of a Point Lesion is Associated With Lesion Formation Via Measurements of the Regional Change in Late Gadolinium Enhancement and T2 Intensity Following Atrial Fibrillation Ablation
Introduction: The Ablation Index (AI) in the CARTO® 3 VISITAG™ Module (Biosense Webster Inc) is a novel measurement that provides a composite metric for ablation and is based on evaluation of power, force, and time parameters.
Hypothesis: AI measurement at each ablation point is associated with regional change in late gadolinium enhancement (LGE) and T2 (edema) intensity following atrial fibrillation (AF) ablation.
Methods: We included 9 patients (age 58.5±7.4 years, 33.3% female, 33.3% persistent AF) that underwent radiofrequency AF ablation using electroanatomic mapping with CARTO® 3 System and pre- and 24-hour post-procedural left atrial (LA) LGE imaging. A subset of 6 patients underwent concomitant pre- and 24-hour post-procedural T2-weighted edema imaging. Retrospectively, ablation point coordinates were registered onto LA LGE and T2 images. The image intensity ratio (IIR) was used to normalize the LGE and T2 sector intensity by mean blood pool intensity and mean paraspinal muscle intensity, respectively.
Results: Overall, 1757 distinct ablation points each with a corresponding pair of pre and post ablation LGE IIR were available. Of these, 1287 had paired T2 IIR measurements. The mean AI was 277.3±88.3. The mean LGE IIR of image sectors increased from 0.93±0.19 to 1.00±0.19 (p<0.001), and the mean T2 IIR increased from 1.38±0.77 to 2.10±0.74 post ablation (p<0.001), respectively. In a mixed effects model, clustered by patient, the change in local LGE IIR was associated with ablation (+0.07, P<0.001) and AI (-0.02, per 100 p<0.001), and the change in T2 IIR was associated with ablation (+0.69, P<0.001) and AI (+0.04 per 100, P=0.01).
Conclusions: Ablation is associated with increased LGE and T2 signal. In the regression models, increasing AI measurement is independently associated with higher T2 signal suggestive of edema, but lower LGE signal suggestive of microvascular obstruction and complete tissue destruction, thus AI is associated with lesion formation.
Author Disclosures: E. Gucuk Ipek: None. T. Zghaib: None. M. Balouch: None. S. Zahid: None. S. Misra: None. A. Prakosa: None. J. Chrispin: None. D. Huang: None. A. Malayeri: None. R. van der Geest: None. J.E. Marine: None. D. Spragg: None. H. Ashikaga: None. R.D. Berger: None. N. Trayanova: None. S.L. Zimmerman: None. H. Calkins: None. S. Nazarian: Research Grant; Significant; Biosense Webster. Consultant/Advisory Board; Significant; Biosense Webster.
- © 2016 by American Heart Association, Inc.