5 years incident stroke, heart failure, acute myocardial infarction, and death in patients having undergone atrial fibrillation ablation according to BMI

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novo Nordisk Introduction Both atrial fibrillation (AF) and obesity have reached epidemic proportions. Obesity is an established risk factor in acute myocardial infarction (AMI), de novo AF, and AF recurrence after ablation. AF increase the risk of stroke, heart failure (HF), and death. The link between body mass index (BMI) and incident stroke, HF, AMI, or death in an AF ablation population is unknown. Purpose To examine incident stroke, HF, AMI, or death by BMI. Method Using Danish nationwide registries, all Danish patients above 18 years who underwent first-time AF ablation from January1st 2010 to December31st 2018 were identified and included at the date of ablation. Underweight patients (BMI < 18.5) were excluded. Exposure of interest was BMI and patients were stratified as normal-weight (BMI 18.5-24.9), overweight (BMI 25.0 – 29.9), obese (30.0 – 34.9), and morbidly obese (BMI ≥ 35.0). The primary endpoint was combined of either first-reached incident stroke, HF, AMI, or death. The 5-year cumulative incidence of the primary endpoint stratified by BMI, was estimated using the Aalen-Johansen estimator. The relative rates were examined using normal-weight as reference in both univariate- and multivariate-Cox models adjusted for prior HF, hypertension, age, diabetes, prior stroke, prior atherosclerotic vascular disease, and sex. Results The study cohort consisted of 7,701 patients. Median age [IQR] decreased from 64 [57, 70] to 60 [53, 66] in normal-weight and morbidly obese respectively. The prevalence of HF, ischemic heart disease, diabetes, and hypertension increased by BMI while prior stroke remained stable. Use of oral anticoagulants remained stable at around 98%. In total 1,285 patients reached the primary endpoint. By decreasing order, the most frequent endpoints were HF (564, 44%), AMI (431, 34%), stroke (199, 15%), and death (91, 7%). The cumulative incidence of the primary endpoint increased incrementally from 15%, 16%, 19%, and 21% from normal-weight to morbidly obese respectively (Figure 1). In the univariate analysis, the Hazard ratio (HR, [95% confidence interval]) increased incrementally from 1.03 [0.90 to 1.18], 1.28 [1.10 to 1.49], 1.43 [1.17 to 1.74] in overweight to morbidly obese respectively (Figure 2). In the multivariate analysis no significant differences were found. The HRs were 0.94 [0.82 to 1.08], 1.05 [0.89 to 1.23], 1.01 [0.82 to 1.24] in the overweight to morbidly obese respectively (Figure 2). Conclusion When identifying obese and morbidly obese AF ablation patients in clinical practice, the risk of either stroke, HF, AMI, or death is higher compared to normal-weight AF ablation patients, but only due to the underlying comorbidities.