Obesity paradox in catheter ablation of atrial fibrillation: analysis of national inpatient sample 2016-2018

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Obesity is a common cardiovascular risk factor and have been associated with favorable outcomes in congestive heart failure, coronary artery disease and atrial fibrillation (Afib), the so-called obesity paradox. Purpose To study the phenomenon of obesity paradox for in-hospital and procedural outcomes in catheter ablation of Afib hospitalizations. Methods We queried January 2016 to December 2018 National Inpatient Sample (NIS) to identify adult (≥18 yrs) hospitalizations with a primary diagnosis of Afib. Patients with appropriate ICD-10 PCS codes for catheter ablation were identified. Obese patients were compared with non-obese patients. We used the Chi-square tests to evaluate the differences between binary or categorical variables, and Student’s t-tests for continuous variables. Multivariate logistic regression was used in outcomes analysis to adjust for potential hospital and patient-level confounders. Results We identified 53,524 weighted catheter ablation of Afib procedural hospitalizations across three years. Of which, 13,335 (25%) of them were associated with obesity. The obese hospitalizations were associated with younger age (mean age 64.0 vs 69.3 yrs; P < 0.01), higher persistent Afib (46.6% vs 37.5%; P < 0.01), higher comorbidity burden (% of >3 Elixhauser comorbidity score 96.8% vs 72.6%; P < 0.01) and had more OSA (43.6% vs 14.7%; P < 0.01). After adjusting for patient and hospital-level characteristics, we observed statistically significant decrease in odds of in-hospital mortality in obese Afib patients undergoing catheter ablation compared to non-obese [Odds Ratio (OR): 0.000004; P < 0.01]. We also observed the obese group had statistically significant association with longer LOS [4.1 vs 3.8 days; P < 0.01], lower total hospitalization charges [US$ 144,882 vs 157,412; P < 0.01] and increased odds of post-operative respiratory failure [OR: 1.97 (1.03 – 3.7); P = 0.04] compared to non-obese group. Conclusion In this large retrospective study of catheter ablation of Afib hospitalizations, higher BMI and obesity was associated with decreased in-hospital mortality consistent with the obesity paradox phenomenon. However, it was associated with longer LOS. The vascular complications and other procedural outcomes except respiratory failure were comparable between both groups. Further prospective studies are necessary to verify our study findings.