Left atrial wall thickness and its relationship with reconnection after pulmonary vein isolation in patients with atrial fibrillation evaluated using a three-dimensional wall thickness map

Abstract

Background The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV reconnection, and thicker wall could be associated with reconnection. Objectives This study aimed to evaluate the wall thickness of the PV antrum in reconnection sites using a three-dimensional (3D) wall thickness map. Methods A total of 91 patients who underwent a second ablation procedure due to AF recurrence were evaluated. The locations of the PV reconnection sites were confirmed in electroanatomical maps. A 3D atrial wall thickness (AWT) map was created using computed tomography scan data. The AWT values of the ablation lines of the index procedure were graded in each segment of the PV antrum: grade 1, 0.5 < AWT ≤ 1.0 mm; grade 2, 1.0 < AWT ≤ 1.5 mm; grade 3, 1.5 < AWT ≤ 2.0 mm; grade 4, 2.0 < AWT ≤ 2.5 mm; grade 5, AWT > 2.5 mm. Results A total of 281 PV reconnection sites among 1256 segments of the PV antrum in 79 patients were detected. The average AWT grades were 2.7 ± 1.0 and 2.2 ± 1.0 in the reconnected and non-reconnected segments, respectively (P < 0.01). Higher AWT grades were observed in the reconnected superior segments of the left superior PV, carina and inferior segments of the left inferior PV, superior and posterior segments of the right superior PV, and posterior and inferior segments of the right inferior PV. Conclusion The reconnected segments of the PV antrum showed thicker myocardium than the non-reconnected ones in patients with recurrent AF after catheter ablation. A wall thickness map for PV isolation could be considered for customized ablation in order to reduce PV reconnection.

Tailored ablation index based on left atrial wall thickness assessed by computed tomography for pulmonary vein isolation in patients with atrial fibrillation

“…14,16 However, these strategies did not include regional LAWT differences. Focusing on previous reports that thicker LAWT is associated with a higher risk of AF recurrence and a higher chance to be reconnected acutely or later, [6][7][8][9][10]17 p < .01) when applying fixed AI guided PVI (500 for anterior and roof segments and 380 for posterior and inferior segments with a maximum interlesion distance of 6 mm). 18 To increase the simplicity of the protocol, 50 AI was added to the fixed AI strategy for the thick segments.…”

“…According to previous studies, the thickness and heterogeneity of LAWT are related to recurrences after AF ablation 6,8,9 . The AF‐recurrence group after catheter ablation was generally associated with a thicker left atrial wall and higher heterogeneity of LAWT than the nonrecurrence group 6,7,10 …”

“…Based on the DICOM format of the CT scan image, a three-dimensional LAWT map for each participant was reconstructed using custom software (using MATLAB R2018b; MathWorks). 10 A comprehensive description is included in the Supporting Information: Methods.…”

“…In our previous report, the segments with LAWT ≥grade 3 were associated with PV reconnection in those who underwent redo AF ablation. 10 We conducted a preliminary analysis to validate the definition of a thick PV antral segment with LAWT ≥grade 3 for acute PV reconnection (the composite of residual potential [RP] after first pass PVI and early reconnection [ER]) in patients who received fixed AI-guided PVI. This retrospective analysis was approved by the Institutional Review Board (H-2002-067-1101).…”

“…6,8,9 The AF-recurrence group after catheter ablation was generally associated with a thicker left atrial wall and higher heterogeneity of LAWT than the nonrecurrence group. 6,7,10 The recently developed ablation index (AI) is utilized widely in therapeutic settings. [11][12][13][14] The weighted AI metric includes contact force, time, and radiofrequency (RF) power and is strongly correlated with lesion formation.…”