Relationship between the time point of left atrial size change and the outcomes of radiofrequency catheter ablation

Abstract Funding Acknowledgements No conflicts of interest INTRODUCTION  Evidence has shown that obesity, expressed as high body mass index (BMI), is associated with the development of atrial fibrillation(AF). However, the relationship between BMI and recurrence of AF after catheter ablation(CA) remains controversial. Understanding this relationship, may help in regard to patient(p) counseling and management before and after CA. Purpose To evaluate single center AF recurrences after pulmonary vein isolation according to BMI status. Secondary endpoints were to compare the influence of other comorbilitys such as pulmonar disease or obstructive sleep apnea(OSA) METHODS We included 114p with AF(54,5 ± 9,6 years; male 75,4%; paroxysmal 70,2%; persistent 29,8%) treated with first time radiofrequency ablation between 2013 and 2018. On the basis of the baseline BMI, patients were categorized into 2 groups: normal/overweigth (BMI < 30kg/m2) and obese(BMI≥30kg/m2). RESULTS There was no significant difference between the majority of baseline characteristics of the groups (table 1), however patients with BMI≥30 were more likely to sufferd OSA(34% vs 8,2%:p = 0,001), to have larger left atrial (diameter > 40mm: 70,5% vs 46,3%;p = 0,004), and persistent AF (43,4% vs 18%; p 0,004). During 12 months of follow-up AF recurred in 34p (29,8%), the freedom from AF was significantly higher in the BMI < 30 group (48p(80%) vs 31(58,5%), p = 0,015). Multivariate analysis including variables of type of AF, OSA, BMI, left atrial size, ejection fraction, and hypertension demonstrated that BMI was the strongest predictor of being freedom from recurrent AF (OR = 0.35, 95% CI: 0,11–0,81, P = 0.014). A serious complication occurred in 6p(5,3%), with no relationship to BMI. CONCLUSION This study suggest that tight association between obesity and AF recurrence after ablation may be partly due to other concomitant conditions which in turn are more frequent in obese patients like OSA, left atrial size and presence of persistent AF. Abstract Table 1