Impact of body mass index on in-hospital outcomes in patients receiving leadless pacemakers: A five-category analysis

Background: The adoption of leadless pacemakers (LPMs) is increasing, yet the impact of body mass index (BMI) on procedural outcomes remains underexplored.

Objective: The purpose of this study was to explore the impact of BMI on in-hospital outcomes for patients receiving LPM implantation.

Methods: Data from the National Inpatient Sample from 2018-2021 were analyzed for patients older than 18 years who underwent LPM implantation, with specific inclusion and exclusion criteria applied. Patients were identified using International Classification of Diseases 10th Revision codes and categorized into BMI groups: underweight, normal, overweight, obese, and morbidly obese. The primary outcome assessed was in-hospital mortality. Secondary outcomes included blood transfusion, pericardial complications, infection/inflammation, removal/revision, and other complications.

Results: The study included 3832 patients who underwent LPM implantation between 2018 and 2021, weighted to represent 19,610 patients, with 3540 having an appropriate BMI designation. Mortality was lower in the obese group (2.3%) compared to the nonobese group (2.7%) (adjusted odds ratio [aOR] 0.462, 95% confidence interval [CI] 0.259-0.623, P = .009). Compared to the normal weight group, those categorized as overweight, obese, and morbidly obese demonstrated a lower risk of in-hospital mortality (aOR 0.432, 95% CI 0.299-0.734, P = .009; aOR 0.465, 95% CI 0.238-0.721, P <.001; aOR 0.299, 95% CI 0.153-0.586, P <.001, respectively).

Conclusion: These findings support the existence of the obesity paradox in patients with LPM implantation, where higher BMI categories are associated with improved mortality outcomes, meeting our prespecified primary endpoint. Further studies are needed to clarify the mechanisms behind these observations.