Abstract 18310: Angiotensin Converting Enzyme Gene Polymorphism is Associated with Reverse Remodeling of Left Atrium after Catheter Ablation of Atrial Fibrillation

Abstract

Background: Although it has been known that radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) induces reverse remodeling of left atrium (LA) and improves left ventricular (LV) function, its mechanism has not been evaluated yet. We hypothesized that genetic polymorphisms in angiotensin converting enzyme (ACE) or angiotensin II type 1 receptor (AT1R) genes may contribute to the changes after RFCA. Methods: We included 263 patients with AF (male 78%, 56±11 years old, paroxysmal AF 70%) who underwent RFCA of AF, and compared pre-procedural and post-RFCA 1-year follow-up echocardiography. LA reverse remodeling was defined as decreased LA size at 1-year after RFCA. Potential 4 ACE (rs4341, rs4362, rs4309, rs4291) and 3 AT1R (rs2675511, rs422858 , and rs5182) related single nucleotide polymorphisms (SNPs) were genotyped and compared with phenotypes of AF patients. Results: Mean LA size decreased (41.4±6.1 vs. 38.5±5.8 mm, p<0.001) at 1-year after RFCA and the reduced LA size after RFCA was observed in 72.2% of patients (n=190). The patients with reverse remodeling were more likely to have larger preprocedural LA size (42.6 ± 5.9 vs. 38.4 ± 5.3 mm, p<0.001) than those without it. Mean LV ejection fraction (LVEF, 63.3±7.8 vs. 65.2±7.5%, p<0.001) increased at 1-year and E/E’ decreased (18.7±4.0 vs. 14.6±3.3 mm, p<0.001) in patients with baseline LV diastolic dysfunction (E/E’≥15). Among the 7 SNPs, ACE gene, rs4309 and rs4291 variants, were significantly associated with reverse remodeling of LA (CC vs. CT+TT; OR 0.407; 95% CI 0.189-0.879, TT vs. AT+AA; OR 0.307; 95% CI 0.114-0.827, respectively). A multiple logistic regression analysis showed that the rs4309 variant (OR 0.400; 95% CI 0.179-0.896) and preprocedural LA size (OR 1.147; 95% CI 1.083-1.215) were independent predictors of the reverse remodeling of LA. Conclusions: Reduction of AF burden by catheter ablation induces reverse remodeling of LA and improves LV systolic and diastolic function, especially in patients with baseline LV diastolic dysfunction. Several ACE polymorphisms were associated with such reverse remodeling of LA in patients with AF.