Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Quality Measures & Complications D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-194 - Elevated Left Atrial Volume Index Is Associated With Incident Atrial Fibrillation After Cavotricuspid Isthmus Ablation For Typical Right Atrial Flutter (ID 961)

Abstract

Background: Despite multiple randomized trials showing benefit of pulmonary vein isolation (PVI) in unselected patients undergoing cavotricuspid isthmus (CTI) dependent atrial flutter (AFL) ablation, prophylactic PVI during CTI AFL ablation has not gained wide acceptance. Previously identified risk factors for incident atrial fibrillation (AF) after CTI AFL ablation include severely elevated left atrial volume index (LAVI) and elevated LA diameter. However, prior studies have been limited by short follow-up time and inclusion of patients with history of AF.
Objective: To identify patients undergoing CTI ablation for AFL most likely to benefit from prophylactic PVI.
Methods: We identified 114 consecutive patients without history of AF who underwent CTI AFL ablation at a single tertiary care center with at least one year follow-up. We analyzed baseline characteristics, electrophysiology study (EPS) data, and echocardiographic data. The primary outcome was incidence of AF at 3 years.
Results: Incident AF was identified in 44 patients over a median follow-up was 549 days. LAVI was the only baseline characteristic significantly different in patients who developed AF compared to those that did not (37cm2 vs 30 cm2, respectively, p=.007). EPS data, including CTI block time, were similar between groups. On ROC analysis LAVI achieved an AUC 0.65 (p = 0.007) for the ability to predict incident AF, and LAVI of 30 mL/m2 had sensitivity 71% and specificity 60% as a predictor of incident AF. Kaplan-Meier estimated incidence of AF at three years was significantly greater in patients with LAVI ≥ 30 mL/m2 than LAVI < 30 mL/m2 (65% vs 22%, p=0.007). A sensitivity analysis comparing risk of incident AF in patients with severely increased LAVI (> 40 mL/m2) to that of LAVI 30-40 mL/m2 showed no difference (67% vs 63%, p=0.97).
Conclusion: LAVI ≥ 30 mL/m2 is associated with significantly increased risk of incident AF following CTI ablation for typical AFL. Two-thirds of patients with any degree of elevated LAVI developed AF within 3 years. The clinical benefit, and cost-effectiveness of prophylactic PVI in patients with elevated LAVI requires further validation.
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