BACKGROUND: Genome-wide association (GWA) studies have identified numerous common polymorphisms associated with atrial fibrillation (AF). The 3 loci most strongly associated with AF occur at chromosome 4q25 (near PITX2), 16q22 (in ZFHX3), and 1q21 (in KCNN3). OBJECTIVE: To evaluate if timing of AF recurrence after direct current cardioversion (DCCV) is modulated by common AF susceptibility alleles. METHODS: 208 patients (age 65±11 years, 77% men) with persistent AF underwent successful DCCV and were prospectively evaluated at 3, 6 and 12 months for AF recurrence. Four single nucleotide polymorphisms (SNPs): rs2200733 and rs10033464 at 4q25; rs7193343 in ZFHX3 and rs13376333 in KCNN3 were genotyped. RESULTS: The final study cohort consisted of 184 patients. In 162 (88%) patients sinus rhythm was restored with DCCV, of which 108 (67%) had AF recurrence at a median of 60 (29 - 176) days. In multivariable analysis, the presence of any common SNP (rs2200733, rs10033464) at the 4q25 locus was an independent predictor of AF recurrence, (hazard ratio [HR]: 2.1, 95% confidence interval [CI]:1.21-3.30, P=0.008). Furthermore, rs2200733 exhibited a graded allelic dose response for early AF recurrence (homozygous variants: 7 [4-56] days, heterozygous: 54 [28-135] days and wild type: 64 [29-180] days, P=0.03). CONCLUSIONS: To our knowledge, this is the first study to evaluate whether genomic markers can predict timing of AF recurrence in patients undergoing elective DCCV. Our findings show that a common polymorphism on chromosome 4q25 (rs2200733) is an independent predictor of AF recurrence after DCCV and point to a potential role of stratification by genotype.
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