Abstract 19080: Association of Atrial Fibrillation Susceptibility Alleles and Intermediate Left Atrial and Pulmonary Vein Phenotypes and Their Impact on Catheter Ablation

Abstract

BACKGROUND: Recent genome-wide association studies have demonstrated that single-nucleotide polymorphisms (SNPs) on chromosomes 16q22 and 1q21 confer risk for atrial fibrillation (AF) but mechanisms and subsequent intermediate phenotypes remain elusive. Here, we analyzed the association between common AF susceptibility alleles and several left atrial and pulmonary vein phenotypes including left atrial and pulmonary vein dimensions and morphology and studied their impact on arrhythmia recurrence after AF ablation. METHODS: In 99 consecutive patients (mean age 61+/- 10 years, 68% male) undergoing catheter ablation for drug-refractory paroxysmal (48 %) or persistent (52 %) AF, left atrial and pulmonary vein dimensions were extracted from the preprocedural acquired multislice computed tomography (MSCT). Pulmonary vein anatomy was evaluated according to common trunk or additional veins. Left atrial voltage mapping was performed to identify scar and low voltage areas. Genotypes of rs7193343 (16q22) and rs13346333 (1q21) were determined. Serial 7-day Holter electrocardiographic recordings were acquired to detect AF recurrences. RESULTS: The presence of rs13346333 (1q21) was associated with a more spherical anatomy of the left atrium defined by the ratio of transversal to anterior-posterior diameter (OR: 0,138; 95% CI 0,022-0,856; p=0,033). In addition, rs7193343 (16q22) was associated with the presence of accessory veins (OR: 3,929; 95% CI 1,009-15,300; p=0,049). AF recurrence between 3 and 12 months occurred in 34,7 % of patients. Among the left atrial and pulmonary vein parameters, the presence of accessory pulmonary veins was associated with a significant lower risk of AF recurrence (OR: 0,587; 95% CI 0,461-0,748; p<0,001). CONCLUSIONS: This study suggests an association between AF susceptibility alleles and anatomic variations of the left atrium and pulmonary veins. Accessory pulmonary veins are dominant AF triggers and their ablation leads to AF elimination.