Chromosome 4q25 Variants Have Less Co-Morbid Risk Factors and High Left Atrial Conduction Velocity in Korean Patients Who Underwent Radiofrequency Catheter Ablation of Atrial Fibrillation

Background: Recent studies have demonstrated the association of 4q25 gene single nucleotide polymorphism (SNP) with atrial fibrillation (AF). We evaluated potential relationships of 4 SNPs on chromosome 4q25 with clinical and electrophysiological characteristics in patients undergoing Catheter ablation for AF. Methods: A total of 295 consecutive patients (56 ± 11 years, 78% male) with paroxysmal (68.7%) or persistent (31.3%) AF were included. Genotyping for 4 SNPs in close proximity to PITX2 gene on chromosome 4q25 (rs2200733, rs10033464, rs17042171, and rs6843082) were performed and compared with clinical, electrophysiological, and imaging database. Results: There were no significant differences in clinical and electrophysiological parameters between major and minor allele group of rs10033464, rs17042171, and rs6843082. In contrast, rs2200733 variant was associated with lower CHADS score (0.73±0.95 vs. 1.17± 1.10, p=0.021), lower prevalence of heart failure (2.5 vs. 11.5%, p=0.023), hypertension (42.3 vs. 68.9%, p=0.006), and patients with age>75 (1.2 vs 6.9%, p=0.030). In electrophysiological study, conduction velocity of left atrium was significantly higher (0.67±0.35 m/s vs. 0.55±0.22 m/s, p=0.042) in patients with variant allele of rs2200733. Conclusions: In Korean population, rs2200733 at 4q25 was the only significant SNPs associated with clinical and electrophysiological trait. It may increase the risk of AF without traditional risk factors and significant electroanatomical remodeling.