Association between weight loss and outcomes in patients undergoing atrial fibrillation ablation: a systematic review and dose–response meta-analysis

Background Obesity is an strong risk factor for atrial fibrillation (AF), and obesity can affect the prognosis of AF. However, the role of weight loss on outcomes after ablation remains unclear. Objectives This study aims to determine the relationship between weight loss and outcomes in patients with AF ablation, as well as the potential dose–response relationship. Methods The Cochrane Library, PubMed, and Embase databases were searched to identify studies that reported a relationship between weight loss and ablation up to August 17, 2021. Relative risks (RRs) were pooled using random-effects models. Results One randomized, open-labeled clinical trial and seven cohort studies involving 1283 patients were included. The mean body mass index of all included studies was over 30 kg/m 2 . The clinical trial showed a non-significant benefit of weight loss intervention on AF recurrence (Odd risk [OR] = 1.02, 95% confidence interval [CI] 0.70–1.47). Meta-analysis based on observational studies showed that the recurrence rate of AF after ablation was significantly reduced (RR = 0.43, 95% CI 0.22–0.81, I 2 = 97%) in relatively obese patients with weight loss compared with the control group. Each 10% reduction in weight was associated with a decreased risk of AF recurrence after ablation (RR = 0.54, 95% CI 0.33–0.88) with high statistical heterogeneity (I 2 = 76%). An inverse linear association (P non-linearity = 0.27) between AF relapse and increasing weight loss was found. Conclusions Our results first suggest an inverse dose–response association between weight loss and risk of recurrent AF after ablation, with moderate certainty. Graphical Abstract