URIC ACID SIGNIFICANTLY CORRELATES WITH THE PRESENCE OF LOW–VOLTAGE AREAS AT THE ENDOCARDIAL MAPPING IN PATIENTS WITH NON–VALVULAR ATRIAL FIBRILLATION

Abstract

Abstract Background Interest in the role of atrial substrate in maintaining Atrial Fibrillation (AF) is growing. Fibrosis is the culprit in the electrical derangement of the myocites. Many cardiovascular risk factors are known to be linked to atrial scarring; among them Uric Acid (UA) is emerging. The purpose of our study is to evaluate whether UA is associated with atrial fibrosis in AF patients. Methods 81 patients who underwent radiofrequency transcatheter ablation for nonvalvular AF at the cardiological department of the Niguarda Hospital were enrolled. UA levels were analysed before the procedure as well as known predictors of atrial fibrosis. High density electroanatomic mapping of the left atrium was performed and patients were divided according to the presence or not of areas of pathological substrate (bipolar voltage < 0.5mV in sinus rhythm). Results 19 patients showed a pathological atrial substrate. The population of patients with pathological atrial substrate was older (64.7±1.6 vs 58.2±10.9 years, p=0.032) and had more often a persistent phenotype of AF (84.3 vs 35.8%, p<0.001). UA levels were significantly higher in the pathological group (6.8±1.9 vs 5.3±1.4, p<0.001) as well as the prevalence of hyperuricemia (26.5 vs 6.5%, p=0.021). The association between uric acid and pathological atrial substrate remains significant even after correction for confounding factors (age, left ventricular dysfunction, valvular disease, AF phenotype and furosemide use). Conclusions In a population of patients who underwent atrial fibrillation’s ablation, higher uric acid’s levels were significantly associated with pathological left atrium’s substrate at electro–anatomical mapping.