Abstract 3290: G674A Polymorphism of the Connexin 40.1 Gene and Atrial Fibrillation in Patients With Dilated Cardiomyopahty
Background: Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and a leading cause of cardiovascular morbidity. The cardiac gap-junction protein connexin is expressed in atrial myocytes and mediates the coordinated electrical activation of the atria. Some polymorphisms in connexin genes were reported to be significantly associated with AF. We hypothesized that polymorphism (G674A) in the connexin 40.1 gene may be associated with AF in patients with dilated cardiomyopathy (DCM).
Methods and Results: We genotyped this polymorphism (G674A, rs595652) in 83 patients with DCM by using the TaqMan chemical method. Patients were classified into AF group (n=21) if they had AF, and sinus rhythm (SR) group (n=62) if they had SR. Distribution of the connexin 40.1 genotypes (G/G, G/A, and A/A) among the total patients with DCM was 27.7%, 54.2%, and 18.1%, respectively. Allele frequency for the A allele was 0.52 in the AF group and 0.43 in the SR group. In a dominant G allele model (G/G and G/A genotypes vs A/A genotype), there was a significant difference in genotypes between the AF group and the SR group (p=0.035). This table⇓ shows odds ratios for atrial fibrillation in patients with DCM determined by logistic regression analysis. The odds of AF in DCM patients with the A/A genotype was 3.38-fold. In addition, age and left atrial dimension were also risk factors.
Conclusion: The A/A genotype in the connexin 40.1 gene is a significant risk factor for AF in patients with DCM.