Does Racial Difference Augment the Obesity Paradox In HFpEF Patients? An Insight from the National Inpatient Sample

Abstract

Introduction Heart failure with preserved ejection fraction (HFpEF) leads to about 500,000 hospitalizations. Prior studies have shown that obesity is paradoxically associated with improved survival in HFpEF patients. However, the majority of the studies have independently focused on the impact of obesity alone on mortality. The impact of racial differences on in-hospital outcomes of obese HFpEF patients has not been well examined. Studies in patients with end-stage renal disease have shown that the race of a patient augments the obesity paradox. Based on this, we entertain the possibility that racial differeces will augment the obesity paradox in HFpEF patients. Methods We queried the 2017 National Inpatient Sample (NIS) database to identify all admissions age 18 years or older with a discharge diagnosis of HFpEF exacerbation. Elixhauser comorbidities index was used to identify obese patients based on ICD-10 codes. We accounted for survey design and built a multivariate logistic regression (MLR) model to investigate in-hospital mortality, length of hospital stay (LOS), and risk of intubation (ROI). MLR model adjusted for patient demographics and Elixhauser comorbidity index. MLR model was then applied to investigate the interaction effects of race on the in-hospital outcomes of obese HFpEF patients. All statistical analyses were completed using R statistical software version 3.6.3. Results After adjusting for survey design, an estimated 921,710 patients had a discharge diagnosis of HFpEF exacerbation, 30% of whom also have a diagnosis of obesity. 74% were White, 14% Black and 7% Hispanic. Mean age was 74, and 60% were women. After adjusting for patient demographics and comorbidities, MLR analysis showed that among HFpEF patients, obesity was associated with reduced in-hospital mortality (OR 0.79; CI 0.74-0.84), increased LOS (OR 1.38; CI 1.35-1.42), and increased ROI (OR 1.2; CI 1.15-1.26). Interaction effects showed that among obese HFpEF patients, being White increased LOS, in-hospital mortality when compared to being Black(p 0.05). Conclusion In our study, racial differences influenced the impact of obesity on in-hospital outcomes of HFpEF patients. Being White increased LOS, in-hospital mortality and ROI when compared to being Black. Finally, being White significantly increased the ROI compared to being Black, Hispanic or Asian. Unsurprisingly, the obesity paradox remains even in HFpEF patients.